Chromosome Evolution Research Papers - Academia.edu (original) (raw)

2025

En este trabajo se realiza un análisis filogenético de 13 especies de Cicindelini presentes en la Península Ibérica. El análisis sitúa al género Cephalota como un taxón basal dentro de este grupo. Las especies Cicindela campestris Linnaeus, 1758 y C. maroccana Fabricius, 1801 muestran una estrecha relación como taxones hermanos. La especie amenazada Cephalota deserticoloides (Codina, 1931) muestra una mayor diversidad genética de la establecida por trabajos previos. El análisis filogenético indica que las especies de Cicindelini presentes en la Península Ibérica no constituyen un grupo monofilético, sino que conforman linajes cuyos parientes más cercanos se encuentran en otras regiones biogeográficas, de acuerdo con las hipótesis que sitúan el origen de los cicindélidos en épocas tempranas de la fragmentación del subcontinente Gondwana.

2025

Salmonids are a heterogeneous group of fish classified in one family -Salmonidae. These species are natives of the northern hemisphere, but currently have been introduced in many countries all over the world for sport fishing and aquaculture. Despite the considerable importance of salmonids, their evolutive history is still a controversial issue. The aim of the current study is to infer the phylogeny within the Salmonidae family using as phylogenetic marker the D-loop region. For this purpose, an PCR amplification of D-loop region, followed by direct sequencing and phylogenetic analysis have been performed in four salmonids species from Romanian fauna -Salmo trutta fario, Salvelinus fontinalis, Thymallus thymallus and Oncorhynchus mykiss. For a more accurate phylogenetic classification of these species within Salmonidae family the analysis included similar sequences from GenBank belonging to 17 salmonid species and an osmerid species used as outgroup. The the phylogenetic trees illustrating the evolutive relationships within Salmonidae were constructed by using Neighbor Joining and Maximum Parsimony methodologies implemented in MEGA5.The phylogenetic analysis using mitochondrial control region as marker has allowed an overview about the positions occupied by Romanian salmonids within the Salmonidae family.

2025, Journal of Mammalogy

Phylogenetic relationships among 7 species of Reithrodontomys were examined using the complete mitochondrial cytochrome-b gene. DNA-sequence data were analyzed using parsimony (weighted and unweighted) and genetic distance methods. In all analyses, R. sumichrasti, R. megalotis, and R. zacatecae formed a monophyletic clade. Likewise, R. montanus and R. raviventris were depicted as sister taxa in all analyses. Our study supports recognition of R. zacatecae as a species distinct from R. megalotis and recognition of R. raviventris as distinct from R. montanus. Patterns of chromosomal evolution were examined using differential staining as resolved by 3 DNA probes and fluorescent in situ hybridization. Using the phylogeny based on DNA sequences, we concluded that there has been extensive chromosomal repatterning (in most cases karyotypic megaevolution) in the evo-

2025

We analyzed the main karyologic changes that have occurred during the dispersal of Triatoma infestans, the main vector of Chagas disease. We identified two allopatric groups, named Andean and non-Andean. The Andean specimens present C-heterochromatic blocks in most of their 22 chromosomes, whereas non-Andean specimens have only 4–7 autosomes with C-banding. These heterochromatin differences are the likely cause of a striking DNA content variation (approximately 30%) between Andean and non-Andean insects. Our study, together with previous historical and genetic data, suggests that T. infestans was originally a sylvatic species, with large quantities of DNA and heterochromatin, inhabiting the Andean region of Bolivia. However, the spread of domestic T. infestans throughout the non-Andean regions only involved insects with an important reduction of heterochromatin and DNA amounts. We propose that heterochromatin and DNA variation mainly reflected adaptive genomic changes that contribut...

2025, Caryologia

It was carried out a cytogenetic comparison between Phyllostomus hastatus and Artibeus lituratus (Chiroptera, Phyllostomidae), using G-, C-and NOR banding techniques. The P. hastatus specimens presented 2n=32 chromosomes, including 13 biarmed autosome pairs and one acrocentric. The X chromosome is submetacentric and the Y is a minute acrocentric. A. lituratus has 2n=30 chromosomes in females and 31 in males specimens. The autosomes are 14 biarmed pairs and the chromosomal sexual system is XY 1 Y 2 type, being the X chromosome a large submetacentric and both Y 1 (real Y) and Y 2 acrocentric elements. Several chromosomal homologies are shared between both taxa, including whole chromosomes and chromosomal arms. Based on similarity of G-banding pattern is proposed that the system XY 1 Y 2 from A. lituratus risen by a tandem fusion event involving the stenodermatine original biarmed X chromosome with the autosome acrocentric homologous to Y 2 .

2025

Dedico esta dissertação a meus amados pais: Doralice de Sena Ferreira e Augusto Pinto Correia; a minha orientadora Sandra Morelli e a equipe de Citogenética Animal da Universidade Federal de Uberlândia. vi "Aqueles que confiam em Javé são como o monte de Sião: nunca se abala esta firme para sempre." Salmo 125, 1 vii AGRADECIMENTOS Agradeço a Deus que é meu fiel companheiro e direciona meus caminhos, dando força e ânimo para seguir em frente. À minha orientadora Sandra Morelli pela sua amizade, carinho, orientação, paciência e por acreditar em mim, mesmo diante todas as dificuldades presentes. Aos meus pais Augusto Pinto Correia e Doralice de Sena Ferreira por todo amor, apoio, paciência, e por compartilharem comigo "mesmo estando longe" todo o processo de desenvolvimento deste mestrado, por sofrerem comigo nos momentos de dificuldades e vibrarem em todos os momentos de alegria. Ao José Clidenor dos Santos, pela sua disposição nas incansáveis coletas e pela amizade. Á amiga Luana por me incentivar a vir para Uberlândia, por todo apoio, por todo exemplo de fé, pela nossa longa amizade que começou com as aves na nossa querida UFT e com a graça de Deus durará por muito tempo. Aos amigos de Laboratório, Robson e Sabrina por serem meus coorientadores, pelo companherismo e pela disposição em me ajudar em todos os momentos que precisei. Em especial a Sabrina, por me socorrer nos grandes momentos de sufoco e ser minha grande conselheira e companheira. Aos amigos Aurélio Herinque, Naiara, Lívia, Daniele e Alessadra por todo carinho e amizade dentro e fora do laboratório. À amiga Ivaneia, que será sempre inesquecível, por me ajudar no trabalho com os primeiros cascudos. Aos novos estagiários, Renan, Carine e Luiz Paulo por todo auxílio, pela disposição, e empolgação com a citogenética, sendo gratificantes e valiosos os trabalhos realizados juntos. Aos colegas de mestrados e professores do Instituto de Genética e Bioquímica, por todo apoio e conhecimento compartilhado.

2025, Chromosome Research

Tenrecs (Tenrecidae) are a widely diversified assemblage of small eutherian mammals that occur in Madagascar and Western and Central Africa. With the exception of a few early karyotypic descriptions based on conventional staining, nothing is known about the chromosomal evolution of this family. We present a detailed analysis of G-banded and molecularly defined chromosomes based on fluorescence in situ hybridization (FISH) that allows a comprehensive comparison between the karyotypes of 11 species of two closely related Malagasy genera, Microgale (10 species) and Oryzorictes (one species), of the subfamily Oryzorictinae. The karyotypes of Microgale taiva and M. parvula (2n = 32) were found to be identical to that of O. hova (2n = 32) most likely reflecting the ancestral karyotypes of both genera, as well as that of the Oryzorictinae. Parsimony analysis of chromosomal rearrangements that could have arisen following Whole Arm Reciprocal Translocations (WARTs) showed, however, that these are more likely to be the result of Robertsonian translocations. A single most parsimonious tree was obtained that provides strong support for three species associations within Microgale, all of which are consistent with previous molecular and morphological investigations. By expanding on a recently published molecular clock for the Tenrecidae we were able to place our findings in a temporal framework that shows strong chromosomal rate heterogeneity within the Oryzorictinae. We use these data to critically examine the possible role of chromosomal rearrangements in speciation within Microgale.

2025

Kawakatsu, Nishino & Ohtaka (2007) reviewed the occurrence records of exotic planarians in Japan (7 species in total of freshwater and land planarians and a single temnocephalid species). Among them, two North American dugesiid species, Girardia tigrina (Girard, 1850) and Girardia dorotocephala (Woodworth, 1897), were found at first in aquaria and/or culture ponds for tropical fish cultures (cf. Hirao, Kawakatsu & Teshirogi, 1970; Kawakatsu & Hirai, 1986; Kawakatsu, Oki, Tamura & Yamayoshi, 1985; Tamura, Oki, Kawakatsu, Ninagawa, Matsumoto & Suzuki, 1985; [Masuda], 2004).

2025, Journal of Mammalogy

Monodelphis (short-tailed opossums) is the most speciose South American marsupial genus, wtih species distributed from Panama to Argentina. The goal of the present study was to analyze levels and patterns of genetic variation in M. brevicaudata (Guianan short-tailed opossum), M. dimidiata (yellow-sided opossum), M. domestica (gray short-tailed opossum), and M. kunsi (pygmy short-tailed opossum) using sequences of the mitochondrial cytochrome b (Cytb) and nuclear interphotoreceptor retinoid-binding protein (IRBP) genes from individuals sampled in the Amazon, Cerrado, Caatinga, Atlantic Forest, and Pampa biomes in Brazil. Species relationships also were analyzed using sequences of 9 other Monodelphis species retrieved from GenBank and representing 3 localities in Brazil and 17 sites in other South American countries. M. domestica and M. brevicaudata showed phylogeographic structure, but M. dimidiata and M. kunsi did not. Maximum parsimony, maximum likelihood, and Bayesian algorithms showed similar topologies for estimated phylogenetic trees. Analyses of individual genes produced comparable results, but combined loci produced trees with higher support. All Monodelphis haplotypes were monophyletic, with M. emiliae (Emilia's short-tailed opossum) sister to all other species, which form 2 groups. M. brevicaudata (from the Amazon) forms a well-supported clade with M. domestica (which occupies several biomes) and 2 unidentified Amazonian species. The other branch has M. kunsi (from the Cerrado) as sister to a well-supported clade of 5 Amazonian species.

2025, BMC Genomics

Background: Over the past years, the relationship between gene transcription and chromosomal location has been studied in a number of different vertebrate genomes. Regional differences in gene expression have been found in several different species. The chicken genome, as the closest sequenced genome relative to mammals, is an important resource for investigating regional effects on transcription in birds and studying the regional dynamics of chromosome evolution by comparative analysis. Results: We used gene expression data to survey eight chicken tissues and create transcriptome maps for all chicken chromosomes. The results reveal the presence of two distinct types of chromosomal regions characterized by clusters of highly or lowly expressed genes. Furthermore, these regions correlate highly with a number of genome characteristics. Regions with clusters of highly expressed genes have higher gene densities, shorter genes, shorter average intron and higher GC content compared to regions with clusters of lowly expressed genes. A comparative analysis between the chicken and human transcriptome maps constructed using similar panels of tissues suggests that the regions with clusters of highly expressed genes are relatively conserved between the two genomes. Conclusions: Our results revealed the presence of a higher order organization of the chicken genome that affects gene expression, confirming similar observations in other species. These results will aid in the further understanding of the regional dynamics of chromosome evolution.

2025, G3: Genes, Genomes, Genetics

Understanding the genomic basis of adaptative intraspecific phenotypic variation is a central goal in conservation genetics and evolutionary biology. Lake trout (Salvelinus namaycush) are an excellent species for addressing the genetic basis for adaptive variation because they express a striking degree of ecophenotypic variation across their range; however, necessary genomic resources are lacking. Here we utilize recently-developed analytical methods and sequencing technologies to (1) construct a high-density linkage and centromere map for lake trout, (2) identify loci underlying variation in traits that differentiate lake trout ecophenotypes and populations, (3) determine the location of the lake trout sex determination locus, and (4) identify chromosomal homologies between lake trout and other salmonids of varying divergence. The resulting linkage map contains 15,740 single nucleotide polymorphisms (SNPs) mapped to 42 linkage groups, likely representing the 42 lake trout chromosomes. Female and male linkage group lengths ranged from 43.07 to 134.64 centimorgans, and 1.97 to 92.87 centimorgans, respectively. We improved the map by determining coordinates for 41 of 42 centromeres, resulting in a map with 8 metacentric chromosomes and 34 acrocentric or telocentric chromosomes. We use the map to localize the sex determination locus and multiple quantitative trait loci (QTL) associated with intraspecific phenotypic divergence including traits related to growth and body condition, patterns of skin pigmentation, and two composite geomorphometric variables quantifying body shape. Two QTL for the presence of vermiculations and spots mapped with high certainty to an arm of linkage group Sna3, growth related traits mapped to two QTL on linkage groups Sna1 and Sna12, and putative body shape QTL were detected on six separate linkage groups. The sex determination locus was mapped to Sna4 with high confidence. Synteny analysis revealed that lake trout and congener Arctic char (Salvelinus alpinus) are likely differentiated by three or four chromosomal fissions, possibly one chromosomal fusion, and 6 or more large inversions. Combining centromere mapping information with putative inversion coordinates revealed that the majority of detected inversions differentiating lake trout from other salmonids are pericentric and located on acrocentric and telocentric linkage groups. Our results suggest that speciation and adaptive divergence within the genus Salvelinus may have been associated with multiple pericentric inversions occurring primarily on acrocentric and telocentric chromosomes. The linkage map presented here will be a critical resource for advancing conservation oriented genomic research on lake trout and exploring chromosomal evolution within and between salmonid species. Linkage map Salvelinus QTL RAD genomics lake trout Maintaining adaptive phenotypic diversity is a central tenet of conservation biology. In many taxa, diversity is produced through selective pressures that favor reduced intraspecific competition and trophic specialization . The evolution of trophically specialized morphotypes has been observed in multiple fish species

2025

We describe the karyotype, location of nucleolus-organizing regions (NORs) and heterochromatin composition and distribution in Lepidochitona caprearum (Scacchi, 1836). The examined specimens had 2n=24 chromosomes; the elements of pairs 1-4 were metacentric, subtelocentric those of the fifth pair, telocentric the elements of other pairs. NOR-FISH, Ag-NOR-and CMA 3 banding showed NORs localized on pericentromeric regions of a medium small sized, telocentric chromosome pair. After C-banding or digestions with restriction enzyme NOR associate heterochromatin only was cytologically evident, resulting CMA 3 positive. The comparison with chromosome data of other chitons, other than to evidence a karyotypic similarity of L. caprearum to species of suborder Acanthochitonina, allows us to infer that chromosome evolution in the suborder mainly occurred via reduction of the number of the chromosomes by centric fusions, which took place repeatedly and independently in the different lineages of Acanthochitonina.

2025, BMC Genomics

BackgroundThe Nile tilapia is the second most important fish in aquaculture. It is an excellent laboratory model, and is closely related to the African lake cichlids famous for their rapid rates of speciation. A suite of genomic resources has been developed for this species, including genetic maps and ESTs. Here we analyze BAC end-sequences to develop comparative physical maps, and estimate the number of genome rearrangements, between tilapia and other model fish species.ResultsWe obtained sequence from one or both ends of 106,259 tilapia BACs. BLAST analysis against the genome assemblies of stickleback, medaka and pufferfish allowed identification of homologies for approximately 25,000 BACs for each species. We calculate that rearrangement breakpoints between tilapia and these species occur about every 3 Mb across the genome. Analysis of 35,000 clones previously assembled into contigs by restriction fingerprints allowed identification of longer-range syntenies.ConclusionsOur data s...

2025, Comparative Cytogenetics

Pipidae is a clade of Anura that diverged relatively early from other frogs in the phylogeny of the group. Pipids have a unique combination of morphological features, some of which appear to represent a mix of adaptations to aquatic life and plesiomorphic characters of Anura. The present study describes the karyotype of Pipa carvalhoi Miranda-Ribeiro, 1937, including morphology, heterochromatin distribution, and location of the NOR site. The diploid number of P. carvalhoi is 2n=20, including three metacentric pairs (1, 4, 8), two submetacentric (2 and 7), three subtelocentric (3, 5, 6), and two telocentric pairs (9 and 10). C-banding detected centromeric blocks of heterochromatin in all chromosome pairs and the NOR detected in chromosome pair 9, as confirmed by FISH using the rDNA 28S probe. The telomeric probes indicated the presence of interstitial telomeric sequences (ITSs), primarily in the centromeric region of the chromosomes, frequently associated with heterochromatin, sugges...

2025

The transition from a unicellular eukaryote to Homo sapiens represents one of the most complex transformations in the history of life. This process, spanning nearly a billion years, involves the emergence of multi-layered regulatory networks, coordinated cellular differentiation, and an immense increase in organismal complexity. The fundamental question remains:
Can standard evolutionary mechanisms—random mutation, natural selection, and genetic drift—adequately account for the rise of complex multicellular life, culminating in homo sapiens?
To assess this, we examine the mutation rates across evolutionary phases, the probability of beneficial mutations fixing in populations, and the constraints imposed by regulatory systems, proteomic complexity, and bioenergetics. While the neo-Darwinian framework assumes a gradual accumulation of mutations leading to increased biological complexity, a detailed analysis of genomic and molecular constraints reveals severe limitations based on evolutionary mechanisms. In particular, the emergence of over 200 general cell types, thousands of neuronal subtypes, and an interconnected proteomic landscape governing cellular function presents formidable challenges. The sheer scale of neuronal interactomes, the orchestration of gene regulatory networks (GRNs), and the energy demands of cognitive processes necessitate an explanation beyond stochastic mutations and incremental selection.

2025, Botanical Journal of the Linnean Society

2025, Botanica Complutensis

Se llevó a cabo un detallado estudio citológico de las células madres de las esporas de ejemplares de B. occidentale procedentes del noroeste de la Argentina. Los resultados de esta contribución permiten dar a conocer un nuevo poliploide, en este caso un hexaploide, cuyo número básico se analiza y discute, estimándose como más probable en x=31. Los datos obtenidos sugieren un origen aloploiploide, es decir, este citótipo nuevo sería producto de hibridación interespecífica y posterior duplicación cromosómica. En el curso del estudio se observó también una notable estabilidad en los rasgos esporangiales, que se consideran diagnósticos en el nivel específico e independiente de la ploidía.

2025, Plant Biology

Orchidaceae is a widely distributed plant family with a very diverse vegetative and floral morphology and such variability is also reflected in their karyotypes. However, since only a low proportion of Orchidaceae has been analysed for... more
Orchidaceae is a widely distributed plant family with a very diverse vegetative and floral morphology and such variability is also reflected in their karyotypes. However, since only a low proportion of Orchidaceae has been analysed for chromosome data, a greater diversity may await to be unveiled. Here we analyse both genome size (GS) and karyotype in two subtribes recently included in the broadened Maxillariineae to detect how much chromosome and GS variation there are in these groups and to evaluate which genome rearrangements were involved in the species evolution. (2) To do so, the GS (14 species), the karyotype -based on chromosome number, heterochromatic banding and 5S and 45S rDNA localisation (18 species) -was characterized and analysed along with published data using phylogenetic approaches. (3) The GS presented a high phylogenetic correlation and it was related to morphological groups in Bifrenaria (larger plantshigher GS). The two largest GS found among genera were caused by different mechanisms: by polyploidy in

2025, The Michigan Botanist

The most recent treatment of Carex section Ovales for Indiana dates to Deam's 1940 "Flora of Indiana." This updated treatment, based upon a thorough review of herbarium material and recent field studies, increases the number of taxa in the state from 17 to 20. Additions include C. missouriensis P. Rothr. & Reznicek, C. projecta Mackenzie, and C. tenera Dewey var. echinodes (Fernald) Wiegand. Nineteen species occur in northern-most Indiana. Southern Indiana is characterized by fewer and widespread species from Carex section Ovales; only C. albolutescens Schweinitz has a predominately southern distribution in the state. Salient taxonomic and ecological notes are provided for each species as well as a key to 27 taxa occurring in Indiana and nearby Illinois, Michigan, and Ohio.

2025, Aliso

Phylogenetic analysis of amplified fragment length polymorphisms (AFLP) was used to infer patterns of morphologic and chromosomal evolution in an eastern North American group of sedges (ENA clade I of Carex sect. Ovales). Distance analyses of AFLP data recover a tree that is topologically congruent with previous phylogenetic estimates based on nuclear ribosomal DNA (nrDNA) sequences and provide support for four species groups within ENA clade I. A maximum likelihood method designed for analysis of restriction site data is used to evaluate the strength of support for alternative topologies. While there is little support for the precise placement of the root, the likelihood of topologies in which any of the four clades identified within the ENA clade I is forced to be paraphyletic is much lower than the likelihood of the optimal tree. Chromosome counts for a sampling of species from throughout sect. Ovales are mapped onto the tree, as well as counts for all species in ENA clade I. Parsimony reconstruction of ancestral character states suggest that: (1) Heilborn's hypothesis that more highly derived species in Carex have higher chromosome counts does not apply within sect. Ovales, (2) the migration to eastern North America involved a decrease in average chromosome count within sect. Ovales, and (3) intermediate chromosome counts are ancestral within ENA clade I. A more precise understanding of chromosomal evolution in Carex should be possible using likelihood analyses that take into account the intraspecific polymorphism and wide range of chromosome counts that characterize the genus.

2025, The Botanical Review

Sedges (Carex: Cyperaceae) exhibit remarkable agmatoploid chromosome series between and within species. This chromosomal diversity is due in large part to the structure of the holocentric chromosomes: fragments that would not be heritable in organisms with monocentric chromosomes have the potential to produce viable gametes in organisms with holocentric chromosomes. The rapid rate of chromosome evolution in the genus and high species diversification rate in the order (Cyperales Hutch., sensu Dahlgren) together suggest that chromosome evolution may play an important role in the evolution of species diversity in Carex. Yet the other genera of the Cyperaceae and their sister group, the Juncaceae, do not show the degree of chromosomal variation found in Carex, despite the fact that diffuse centromeres are a synapomorphy for the entire clade. Moreover, fission and fusion apparently account for the majority of chromosome number changes in Carex, with relatively little duplication of whole chromosomes, whereas polyploidy is relatively important in the other sedge genera. In this paper, we review the cytologic and taxonomic literature on chromosome evolution in Carex and identify unanswered questions and directions for future research. In the end, an integration of biosystematic, cytogenetic, and genomic studies across the Cyperaceae will be needed to address the question of what role chromosome evolution plays in species diversification within Carex and the Cyperaceae as a whole.

2024, Chiroptera …

New report on Sturnira aratathomasi diet and some notes on its distribution in Colombia. The natural history and distribution of many bat species is still unknown, especially for those restricted to mountain environments. A genus with most of its species found in the Andes is Sturnira, been Sturnira aratathomasi the largest in the genus but also a species whose biology and ecology is poorly known. Here we report for the first time, a fruit consumed by this species and we review its distribution. A study of the bat assemblage was carried out in a humid montane forest in the Central Andes of Colombia and fecal samples were collected to compare them with a plant reference built for this study. Five individuals of Sturnira aratathomasi were captured and two fecal samples were collected with seeds from Solanum sycophanta Dunal 1852, a tree found in mature and early secondary forests. This finding corroborates the strong association between the genus Sturnira and the Solanaceae family. A literary review of the species was carried out and geographical coordinates were obtained, plotted afterwards on geographical information system map of South America and Colombia. The distribution of Sturnira aratathomasi, with an emphasis in Colombia, confirms that it is restricted to habitats over 1650m and associated to Andean forests. Comments on other reports are made.

2024, Interciencia

Cervigón, 1993), from Panama and Margarita Island, Venezuela, possess a 2n=48 uniarmed chromosome karyotype (Nirchio et al., 2003). In contrast, specimens of M. curema (sensu Cervigón, 1993), also collected from Margarita Island, have a 2n=24, entirely biarmed chromosome karyotype (Nirchio et al., 2003). Thus, cytogenetic data provided important support to the hypothesis that nominal M. gaimardianus,

2024, Insects

Meloidae are commonly known as blister beetles, so called for the secretion of cantharidin, a toxic substance that causes irritation and blistering. There has been a recent increase in the interest of the cantharidin anticancer potential of this insect group. Cytogenetic and molecular data in this group are scarce. In this study, we performed a karyotype analysis of Hycleus scutellatus, an endemic species of the Iberian Peninsula. We determined its chromosome number, 2n = 20, as well as the presence of the X and Y sex chromosomes. In addition to a karyotype analysis, we carried out DAPI staining. By fluorescence in situ hybridization we mapped the rDNA clusters on 12 different chromosomes. Compared to others, this species shows an unusually high number of chromosomes carrying rDNA. This is one of the highest numbers of rDNA sites found in the Polyphaga suborder (Coleoptera). Additionally, we isolated a satellite DNA family (Hyscu-H), which was located within the pericentromeric regi...

2024, GenomeBiology.com (London. Print)

Background: Gene loss, inversions, translocations, and other chromosomal rearrangements vary among species, resulting in different rates of structural genome evolution. Major chromosomal rearrangements are rare in most eukaryotes, giving large regions with the same genes in the same order and orientation across species. These regions of macrosynteny have been very useful for locating homologous genes in different species and to guide the assembly of genome sequences. Previous analyses in the fungi have indicated that macrosynteny is rare; instead, comparisons across species show no synteny or only microsyntenic regions encompassing usually five or fewer genes. To test the hypothesis that chromosomal evolution is different in the fungi compared to other eukaryotes, synteny was compared between species of the major fungal taxa. Results: These analyses identified a novel form of evolution in which genes are conserved within homologous chromosomes, but with randomized orders and orientations. This mode of evolution is designated mesosynteny, to differentiate it from micro-and macrosynteny seen in other organisms. Mesosynteny is an alternative evolutionary pathway very different from macrosyntenic conservation. Surprisingly, mesosynteny was not found in all fungal groups. Instead, mesosynteny appears to be restricted to filamentous Ascomycetes and was most striking between species in the Dothideomycetes. Conclusions: The existence of mesosynteny between relatively distantly related Ascomycetes could be explained by a high frequency of chromosomal inversions, but translocations must be extremely rare. The mechanism for this phenomenon is not known, but presumably involves generation of frequent inversions during meiosis.

2024, Evolutionary and dispersal history of Triatoma infestans, main vector of Chagas disease, by chromosomal markers

d INTERTRYP (Interactions hôtes-vecteurs-parasites dans les infections par trypanosomatidae),

2024, Mastozoología neotropical

2024, Cancer Genetics and Cytogenetics

Renal cell carcinoma (RCC) is the most common kidney cancer, and accounts for ~3% of all adult malignancies. RCC has proven refractory to conventional treatment modalities but appears to be the only histological form that shows any consistent response to immunotherapeutic approaches. The development of a clinically effective vaccine remains a major strategic target for devising active specific immunotherapy in RCC. We aimed to identify a highly immunogenic antigenic format for immunotherapeutic approaches, so as to boost immune responses in RCC patients. We established and cloned an immunogenic cell line, RCC85#21 named Elthem, which was derived from a non-aggressive and non-metastatic clear cell carcinoma. The cell line characterization was performed by genomics (real-time PCR, genome instability), proteomics (two dimensional electrophoresis, mass spectro-metry) and immunological analysis (mixed lymphocytes tumor cell cultures). Real-time PCR confirmed the RCC85#21 cell expression of tumor antigens and cytokine genes. No difference in microsatellite instability (MSI) in RCC85#21 cell line was found as compared to control, loss of heterozygosity was observed in the RCC85#21 clone, but not in the renal cancer cell lines from which it was generated. The image analysis of RCC85#21 by two-dimensional gels showed 700±26 spots and 119 spots were identified by mass spectrometry analysis. RCC85#21 promoted a significant RCC-specific T cells activation by exhibiting a cytotoxic phenotype after mixed lymphocyte and tumor cell cultures. CD8 + T cells isolated from RCC patients displayed an elevated reactivity against RCC85#21 and efficiently lysed the RCC85#21 clone. The RCC85#21 immunogenic cell line will be suitable for immune stimulation. The identification of novel tumor associated antigens will allow the evaluation of the immune response in vitro and, subsequently, in vivo paving the way for new immunotherapeutic strategies in the RCC setting.

2024

Differential chromosomal markers between sympatric karyomorphs of the fi sh Hoplias malabaricus (Bloch, 1794) (Characiformes: Erythrinidae)

2024, Cytogenetic and Genome Research

volved heterochromatic additions, centric fusions, tandem fusions, pericentric inversions, as well as the addition of interstitial DNA not identified by chromosome paints or C-banding. The hypothesis that the ancestral karyotype for this complex had a diploid number of 52, a fundamental number of 52, and a G-band pattern of which most, if not all are similar to that present in modern day S. hispidus fails to be rejected. This hypothesis remains viable as an explanation of chromosomal evolution in Sigmodontine rodents.

2024, Journal of Heredity

We studied the chromosomal distribution of telomere repeats (TTAGGG) n in 8 species of Sigmodon (cotton rats) using chromosome paints fluorescent in situ hybridization (FISH) from Sigmodon hispidus. In 2 species with the proposed primitive karyotype for the genus, telomere repeats were restricted to telomeric sites. But in the other 6 species that include 3 with proposed primitive karyotypes and 3 with highly rearranged karyotypes, telomere repeats were found on both telomeric sites and within interstitial telomeric sites (ITSs). To explain the distribution of ITS in Sigmodon, we gather data from C-bands, silver nitrate staining, G-bands, and chromosomal paint data from previous published studies. We did find some correlation with ITS and heterochromatin, euchromatic chromosomal rearrangements, and nucleolar organizing regions. No one type of chromosomal structure explains all ITS in Sigmodon. Multiple explanations and mechanisms for movement of intragenomic sequences are required to explain ITS in this genus. We rejected the hypothesis that age of a lineage correlates with the presence of ITS using divergence time estimate analyses. This multigene phylogeny places species with ITS (S. arizonae, S. fulviventer, S. hispidus, S. mascotensis, S. ochrognathus, and S. toltecus) in the clade with a species without ITS (S. hirsutus). Lineages with ITS (S. arizonae and S. mascotensis) arose independently from a lineage absent of ITS (S. hirsutus) around 0.67 to 0.83 Ma. The rearranged karyotypes of S. mascotensis and S. arizonae appear to be an independently derived autapomorphic characters, supporting a fast rate of chromosomal changes that vary among species.

2024, Zoologischer Anzeiger - A Journal of Comparative Zoology

Microhylid frogs are a group of largely unresolved phylogeny, and diverse data sets are needed to improve the evolutionary understanding of these amphibians. We here report karyological data for 22 species of this family, belonging to the Malagasy genera Anodonthyla, Cophyla, Platypelis, Plethodontohyla, Rhombophryne, and Stumpffia (Cophylinae); Scaphiophryne and Paradoxophyla (Scaphiophryninae); and Dyscophus (Dyscophinae); and the Asian genera Calluella and Ramanella (Microhylinae). All species studied have 2n ¼ 26 chromosomes, most of which are metacentric or submetacentric. Chromosome morphology, banding pattern, and position of the nucleolar organizer regions (NORs) provide relevant characters for the understanding of the phylogeny and systematics of these frogs. The species of the Cophylinae are characterized by a subtelocentric or telocentric fourth chromosome pair (submetacentric only in Anodonthyla), which can be seen as a synapomorphy for this subfamily. Shifts in NOR position within the Cophylinae are frequent and agree with recent mitochondrial DNA data, corroborating the non-monophyly of the genus Plethodontohyla. Changes of NOR position and chromosome morphology (i.e., occurrence of subtelocentric and telocentric elements) were also common in this subfamily, possibly being related to their faster mitochondrial substitution rate and high species diversity. The ninth chromosome pair of the examined specimens of Dyscophus guineti, all juveniles, is heteromorphic. In this pair, one of the two chromosomes is longer due to the addition of two heterochromatic segments, raising the possibility that one chromosome of this pair may be a sex chromosome.

2024

The following full text is a publisher's version.

2024, Chromosome Research

We describe the karyotype, location of nucleolus-organizing regions (NORs) and heterochromatin distribution and composition in the Antarctic chiton Nuttallochiton mirandus. Specimens had a karyotype of 2n=32 chromosomes, of which two were microchromosomes. Among macrochromosomes, the elements of the first and fourth pair were bi-armed, the others were telocentric. At least six NOR sites were detected with NOR-FISH, but only four were Ag-NOR-banding-positive. The two microchromosomes were essentially euchromatic, while all macrochromosomes exhibited clear pericentromeric C bands that were found to be AT-rich (being quinacrineand DAPI-positive) and resistant to digestion with AluI and HaeIII. N. mirandus has the largest number of chromosomes (2n=32) and telocentric elements (26) of all the chiton species studied to date. The karyological results of our study agree with previous molecular data indicating N. mirandus as a sister taxon of Acanthochitona crinita. The karyotypes of the two species could be related as a result of Robertsonian rearrangements. According to the more parsimonious hypothesis, the former would be the primitive karyotype, although other evolutionary events cannot be ruled out.

2024, gazi university journal of science

In this study, results and 265 Spalax specimens obtained from the field studies performed between 1994 and 2002 were used. According to these data, reproduction period of Turkish Spalax Guldenstaedt, 1770 lasted from February to July. Turkish Spalax was distributed in areas from sea level up to 2900 meters such as cultivated areas, sparse woodland, steppes, mountain slopes where ground was suitable for burrowing, but not in dense forest. They were not distributed around Kırklareli in Thrace, costal part of Black Sea region and Antalya district, southern and southeastern parts of Van Lake. Their burrows consisted of a nest chamber, toilet room, storage room, and feeding galleries close to surface. They were feed on carrot, potato, onion, wheat seeds and clover in laboratory conditions. When they found in cultivated areas, they can cause damage especially to potatoes, onion, carrot, garlic and sugar beet. Blind mole rats were feed on underground parts and sometimes leaves of plants. Population density could reach up to 6 animals in an area of 1000 m 2. Sex ratio was determined as 40.77 % for males and 59.23 % for females based on 260 specimens identified sexually.

2024

Chromosome numbers of 14 species of Cyperaceae recently collected from the Manaslu Himalaya in Central Nepal are presented. Chromosome numbers for Carex inanis Kunth (2n = 42), C. rufulistolon T. Koyama (2n = 46), and C. speciosa Kunth (2n = 44) are reported here for the first time. Our findings of 2n = 40 for Blysmus compressus (L.) Panz. ex Link, 2n = 46 for C. filicina Nees, and 2n = 32 for Isolepis setacea (L.) R. Br. differ from previously published reports. Chromosome numbers of C. atrofusca Schkuhr subsp. minor (Boott) T. Koyama (2n = 48), Cyperus haspan L. (2n = 26), Eleocharis congesta D. Don (2n = 20), Fimbristylis dichotoma (L.) Vahl (2n = 20), F. littoralis Gaudich (2n = 10), F. schoenoides (Retz.) Vahl (2n = 10), Lipocarpha chinensis (Osbeck) Kern (2n = 26), and Schoenoplectus juncoides (Roxb.) Palla (2n = 74) coincide with past reports.

2024, Zoological Journal of the Linnean Society

Phylogenetic relationships based on 324 base pairs of the mitochondria1 cytochrome b gene were examined in 14 species of the genus Cynolebias. The monophyly of the genus relative to three outgroup taxa belonging to the famify Rivulidae was supported by the sequence data. Bootstrap values corroborated the existence of intrageneric monophyletic units in both parsimony and Neighbour-joining analyses. These include a Cynolebias bellottii-C. wolterstorclade, a C. adlo#-2, C. duratnensis, C. viarius and C. adlofi-1 group, and a C. gyrnnoventris, C. luteojlammulatus pair and the strongly supported assemblage that includes C. prognuthus and C. cheradophilus clade. Phylogenetic relationships remain poorly supported for C. nigripinnis, C. a@nis and C. alexandri, and unresolved among the previous ingroup clades. Cytochrome b sequences reveal an unexpectedly high level of divergence among species of the genus Cynolebias. Consequently, cytochrome b shows good resolution of recent cladogenetic events but limited phylogenetic information at deeper nodes. High levels of sequence divergence span a broad range within Cjnolebias. The highest sequence divergence (c. 28%) occurred among C. antenori and the remaining species of the genus. The minimum divergence value (4.5%) is exhibited by sympatric species C. cheradophilus and C. prognuthus.

2024, Chromosome Research

Extensive chromosome variation involving Robertsonian and non-Robertsonian changes were proposed to explain chromosomal evolution within killifishes of the aplocheiloid group belonging to the order Cyprinodontiforms. In the present work we describe the karyotypes of four Cynolebias species and analyze chromosome changes by means of mitochondrial phylogenetic studies, including 10 taxa of this genus. Diploid numbers varied from 48 to 44

2024, Bitlis Eren üniversitesi fen bilimleri dergisi

Öz Bu çalışmada, farklı lokaliteler dikkate alınarak Nevşehir ilinden toplanan Gnaphosidae familyasına ait Drassodes lacertosus türünün karyolojik özellikleri ilk kez araştırılmıştır. Kromozom preparatlarının elde edilmesinde, Pekâr ve Krâl (2001) yöntemine göre klâsik giemsa boyama protokolü uygulanmıştır. Türün diploid kromozom sayısı 2n=22♂ ve eşey kromozom sistemi X1X20'dır. Otozomların ve eşey kromozomların morfolojisi telosentrik tipte bulunmuştur. Otozomal kromozomların relatif uzunlukları % 9,46-% 6,90 arasında kademeli olarak bir azalış gösterirken; eşey kromozomlarının relatif uzunlukları X1=% 10,76 ve X2=% 6,67 olarak tespit edilmiştir. Karyotipte X1'in en büyük kromozom olduğu, X2'nin ise en küçük kromozom olduğu belirlenmiştir. Mayoz bölünmenin profaz 1 ve metafaz 1 evresinde eşey kromozomları pozitif heteropiknotik özellik gösterirken; mayoz bölünmeye ait diğer evrelerde ise izopiknotik özellik göstermektedir. Mayoz bölünmeye ait evrelerin değerlendirilmesiyle birlikte D. lacertosus türünün kiyazmatik mayoz özelliği taşıdığı saptanmıştır. Sonuç olarak günümüze kadar elde edilen sitogenetik çalışmalarla birlikte; bu çalışmada, Drassodes lacertosus'a ait elde edilen ilk karyolojik bulgular, Drassodes cinsi için yeni veriler sunmakta ve Gnaphosidae familyasına ait türlerin sitogenetiğine katkılar sağlamaktadır.

2024

Resumen The karyotype of Peromyscus grandis (Rodentia:

2024, Italian Journal of Zoology

2024

Background Eighty years since Dobzhansky and Mayr unified Darwinian evolution and Mendelian genetics in the Modern Synthesis [1, 2], we still seek full understanding of speciation's genetic basis [3-7]. In its simplest conception,... more

2024

Six species of Adelpha Hübner from Balneário Barra do Sul (Santa Catarina) and Morretes (Paraná) were collected as eggs or larvae and reared in captivity, aiming to provide descriptions and photography of the immature stages and imagoes. The species studied were Adelpha radiata radiata Fruhstorfer; Adelpha serpa serpa (Boisduval); Adelpha plesaure plesaure Hübner; Adelpha thesprotia (C. Felder & R. Felder); Adelpha lycorias lycorias (Godart); and Adelpha capucinus velia (C. Felder & R. Felder). Two new records of host plants were provided, Tapirira guianensis Aubl. for A. radiata radiata and Heteropterys for A. capucinus velia. This study provides a summary of host plants and the seasonality of occurrence of immature stages of these species. Data were organized in photographic plates that could be useful for the identification process.

2024, Antenor

A new subspecies of Heliconius antiochus (Linnaeus, 1767) (Heliconiinae) from Venezuela is described and illustrated.

2024, Caryologia

Among the great marine fish diversity, the Order Tetraodontiformes is remarkable by presenting post-Perciformes modern features, representing one of the major branches of the teleosteans radiation. Patterns of chromosomal evolution in this group are not fully understood. In the present work, cytogenetical analyses were carried out in the species Balistes vetula (2n=44; FN=44) and Melichthys niger (2n=40 and FN=40) (Balistidae), Chilomycterus antennatus (2n=52; 6M+46st/a, FN=58) (Diodontidae) and Sphoeroides testudineus (2n=46; 18m+4sm+6st+18a, FN=74) (Tetraodontidae), collected along the Brazilian coast and Saint Pauls Rocks. All species presented Ag-NORs sites on a single chromosomal pair. Heterochromatic regions in this group are reduced and located at centromeric position over most of chromosomal pairs. The evolutionary patterns of chromosomal changes were diverse in the distinct Tetraodontiformes families. In Balistidae, the evolution process seems to be determined by in tandem or centric fusions, followed by pericentric inversions. The higher chromosomal number in Diodontidae indicates that centric fissions and pericentric inversions played an important role in the karyotypical definition of this group. The Tetraodontidae S. testudineus displayed small chromosomes with a modal number shared with other species previously analyzed from this family. Such great karyotypical diversity is compatible with a scenario of several modifications established by the adaptative irradiation of this group.

2024

Three sympatric forms have been found within the morphospecies Ceroglossus chilensis Esch. through karyotype analysis and characterization of repetitive DNA families. The male chromosome number of these forms is 2n = 28 + XY (form A), 2n = 40 + XY (form B), and 2n = 38 + trivalent (form C). Restriction enzyme analysis of total genomic DNA of form B using EcoRI produces several conspicuous bands corresponding to monomers and dimers of two repetitive DNA families, of about 575 bp and 200 bp respectively; form C has, after total digestion, only one band of 625 bp corresponding to the monomer of a different repetitive DNA family; and form A has no conspicuous band after this treatment. In situ hybridization experiments show that repetitive DNAs are specific for each form and no crossed hybridization is observed. The results suggest that these Ceroglossus forms are actually a complex of sibling species evolving as separate evolutionary and phylogenetic units, whose characterization at the morphological, ecological and geographical levels should be the subject of further investigation.

2024, Journal of entomology and zoology studies

For present studies click beetles were collected from various localities of Tandojam. Further examination and identification was carried out at Insect Systematic Postgraduate Laboratory, Department of Entomology, Sindh Agriculture University Tandojam. Specimens were collected through traditional hand net and on light trap from various localities and were killed in a jar containing potassium cyanide and mounted through entomological pins. To identify the specimen up to the species level, they were run through the keys available for the region in various publications. Images of habitus and genitalia were taken with cameras fitted on microscope. In present study total 73 members of the family Elateridae were collected from Tandojam, Sindh, Pakistan. This revealed the occurrence 08 species under three subfamilies. Sub-family Agrypninae with five species under three tribes; Agrypnini including, Agrypnus ellipticus (Candèze, 1857) and Agrypnus thibetanus Reitter 1913; Pseudomelanactini wi...

2024, Journal of entomology and zoology studies

For present studies click beetles were collected from various localities of Tandojam. Further examination and identification was carried out at