Pedro Lorite | University of Jaen (original) (raw)
Papers by Pedro Lorite
Genes
Hippodamia variegata is one of the most commercialized ladybirds used for the biological control ... more Hippodamia variegata is one of the most commercialized ladybirds used for the biological control of aphid pest species in many economically important crops. This species is the first Coccinellidae whose satellitome has been studied by applying new sequencing technologies and bioinformatics tools. We found that 47% of the H. variegata genome is composed of repeated sequences. We identified 30 satellite DNA (satDNA) families with a median intragenomic divergence of 5.75% and A+T content between 45.6% and 74.7%. This species shows satDNA families with highly variable sizes although the most common size is 100–200 bp. However, we highlight the existence of a satDNA family with a repeat unit of 2 kb, the largest repeat unit described in Coleoptera. PCR amplifications for fluorescence in situ hybridization (FISH) probe generation were performed for the four most abundant satDNA families. FISH with the most abundant satDNA family as a probe shows its pericentromeric location on all chromos...
Sociobiology
A list of morphological characters to separate Iberoformica and Formica (Serviformica) (F. fusca ... more A list of morphological characters to separate Iberoformica and Formica (Serviformica) (F. fusca species group) is provided. Sexual forms of Formica gerardi Bondroit are described based on Iberian material and reinstated into the subgenus Serviformica based on genetic data and morphological characters. The status of †F.horrida Wheeler, 1915 is assessed.
Molecular Biology Reports
European Journal of Entomology
Cellular & Molecular Immunology
Genetica, Jan 25, 2018
The complete mitogenome of Talpa occidentalis, the Iberian mole, was sequenced using a combinatio... more The complete mitogenome of Talpa occidentalis, the Iberian mole, was sequenced using a combination of the Illumina and Sanger methods. The 16,962 bp genome obtained contains 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNAs, and a control region. Thirty-seven identical repetitions of a 10-nucleotide (CACACGTACG) repeat element were identified in the non-coding control region (D-loop). The number, order, and orientation of the mitochondrial genes are the same as in T. europaea, the only mitogenome published so far for this genus. These two mitogenomes differ only at the repeat element included in the control region. The phylogeny obtained for the Talpidae species using the protein-coding genes of these mitogenomes agrees with the current classification of this family.
Archivum immunologiae et therapiae experimentalis, Jan 25, 2018
Celiac disease is an autoimmune condition triggered by the ingestion of gluten, the protein fract... more Celiac disease is an autoimmune condition triggered by the ingestion of gluten, the protein fraction of wheat, barley and rye. It is not simply an intestinal disease; it is multifactorial caused by many different genetic factors acting together with non-genetic causes. Similar to other autoimmune diseases, celiac disease is a polygenic disorder for which the major histocompatibility complex locus is the most important genetic factor, and is the result of an immune response to self-antigens leading to tissue destruction and the autoantibodies production. Celiac disease exemplifies how an illness can have autoimmune-like features having to be driven by exogenous antigen and how can be reasonably considered as a model of organ-specific autoimmunity.
International journal of molecular sciences, Jan 24, 2018
Chagas disease or American trypanosomiasis affects six to seven million people worldwide, mostly ... more Chagas disease or American trypanosomiasis affects six to seven million people worldwide, mostly in Latin America. This disease is transmitted by hematophagous insects known as "kissing bugs" (Hemiptera, Triatominae), with and being the two most important vector species. Despite the fact that both species present the same diploid chromosome number (2 = 22), they have remarkable differences in their total DNA content, chromosome structure and genome organization. Variations in the DNA genome size are expected to be due to differences in the amount of repetitive DNA sequences. The genome-wide analysis revealed the existence of 42 satellite DNA families. BLAST searches of these sequences against the genome assembly revealed that only four of these satellite DNA families are shared between both species, suggesting a great differentiation between the and genomes. Fluorescence in situ hybridization (FISH) location of these repetitive DNAs in both species showed that they are dis...
Organisms Diversity & Evolution
Parasites & Vectors
Background: The analysis of the chromosomal and genome evolution in organisms with holocentric ch... more Background: The analysis of the chromosomal and genome evolution in organisms with holocentric chromosomes is restricted by the lack of primary constriction or centromere. An interesting group is the hemipteran subfamily Triatominae, vectors of Chagas disease, which affects around 6 to 7 million people worldwide. This group exhibits extensive variability in the number and chromosomal location of repeated sequences such as heterochromatin and ribosomal genes. This paper tries to reveal the significant differences of the repeated sequences among Triatoma species through the use of genomic DNA probes. Methods: We analysed the chromosomal distribution and evolution of repeated sequences in Triatoma species by genomic in situ hybridization (GISH) using genomic DNA probes from two North American Triatoma species. These genomic probes were hybridized both on their own chromosomes and on other Triatoma species from North and South America, with different amounts and chromosome location of C-heterochromatin. The results were compared with those previously described using South American Triatoma genomic probes. Results: We observed two chromosomal hybridization patterns: (i) very intense hybridization signals concentrated on specific chromosomal regions or particular chromosomes; and (ii) lower intensity hybridization signals dispersed along all chromosomes. Self-GISH on T. rubrofasciata and T. dimidiata chromosomes presented strong hybridization signals on all C-heterochromatin regions. However, when we perform genomic cross-hybridizations, only strong signals are detected on the Y chromosome, leaving the C-heterochromatic autosomal regions unmarked. Conclusions: We confirm that repeated DNA of the Y chromosome is shared among Triatoma species and probably represents an ancestral character of the Triatomini tribe. On the contrary, autosomal heterochromatic regions are constituted by species-specific DNA repeats, most probably satDNA families, suggesting that Triatoma speciation involved the amplification of diverse types of autosomal repeats. Molecular characterization of principal repetitive DNAs seems to be an appropriate approach to infer evolutionary relationships in triatomines.
PloS one, 2017
Triatoma infestans is the most important Chagas disease vector in South America. Two main evoluti... more Triatoma infestans is the most important Chagas disease vector in South America. Two main evolutionary lineages, named Andean and non-Andean, have been recognized by geographical distribution, phenetic and genetic characteristics. One of the main differences is the genomic size, varying over 30% in their haploid DNA content. Here we realize a genome wide analysis to compare the repetitive genome fraction (repeatome) between both lineages in order to identify the main repetitive DNA changes occurred during T. infestans differentiation process. RepeatExplorer analysis using Illumina reads showed that both lineages exhibit the same amount of non-repeat sequences, and that satellite DNA is by far the major component of repetitive DNA and the main responsible for the genome size differentiation between both lineages. We characterize 42 satellite DNA families, which are virtually all present in both lineages but with different amount in each lineage. Furthermore, chromosomal location of s...
The Indian journal of medical research, 2016
Insulin regulated aminopeptidase (IRAP) has been related to certain pathologies such as breast ca... more Insulin regulated aminopeptidase (IRAP) has been related to certain pathologies such as breast cancer, Alzheimer΄s disease and septic shock. IRAP is encoded by the leucyl/cystinyl aminopeptidase (LNPEP) gene. The genetic variation in the LNPEP gene has been analyzed in relation with the mortality and vasopressin clearance in septic shock. The LNPEP rs4869317 SNP (single nucleotide polymorphism) was the most significantly associated SNP with vasopressinase activity, being TT genotype associated with increased mortality. The objective of the present study was to develop a simple method to allow a quick and affordable genotyping for the rs4869317 SNP of LNPEP gene. Blood DNA samples were obtained from randomly selected healthy volunteers (n=28). A pair of primers was designed to amplify an 834 bp region of the LNPEP gene containing the rs4869317 SNP. The two alleles (T or A) were detected by digestion of the PCR products with the PacI restriction endonuclease. This enzyme only cuts the...
Comparative Cytogenetics, 2016
Citation: Pita S, Panzera F, Mora P, Vela J, Palomeque T, Lorite P (2016) The presence of the anc... more Citation: Pita S, Panzera F, Mora P, Vela J, Palomeque T, Lorite P (2016) The presence of the ancestral insect telomeric motif in kissing bugs (Triatominae) rules out the hypothesis of its loss in evolutionarily advanced Heteroptera Abstract Next-generation sequencing data analysis on Triatoma infestans Klug, 1834 (Heteroptera, Cimicomorpha, Reduviidae) revealed the presence of the ancestral insect (TTAGG) n telomeric motif in its genome. Fluorescence in situ hybridization confirms that chromosomes bear this telomeric sequence in their chromosomal ends. Furthermore, motif amount estimation was about 0.03% of the total genome, so that the average telomere length in each chromosomal end is almost 18 kb long. We also detected the presence of (TTAGG) n telomeric repeat in mitotic and meiotic chromosomes in other three species of Triatominae: Triatoma dimidiata Latreille, 1811, Dipetalogaster maxima Uhler, 1894, and Rhodnius prolixus Ståhl, 1859. This is the first report of the (TTAGG) n telomeric repeat in the infraorder Cimicomorpha, contradicting the currently accepted hypothesis that evolutionarily recent heteropterans lack this ancestral insect telomeric sequence.
Journal of Medical Entomology, 2016
In order to provide a broad picture on the origin and evolution of holocentric X chromosomes in h... more In order to provide a broad picture on the origin and evolution of holocentric X chromosomes in heteropteran species, we prepared a sex chromosome painting probe by microdissection of the X1 and X2 chromosomes from a kissing bug Mepraia spinolai (Hemiptera: Reduviidae: Triatominae). Fluorescence in situ hybridization on four species of the Triatomini having different amounts of autosomal heterochromatin and sex chromosome systems show that the Xs probe hybridizes on the euchromatin, located both on autosomes and X chromosomes. The heterochromatic Y chromosome and autosomal heterochromatic regions always appear free of hybridization signals. The hybridization results of the Xs probe on Rhodnius prolixus (Rhodniini) is completely different to that observed in Triatomini species. The hybridization signals are small and scattered on all euchromatin, without specific regions including the X chromosome. These results are in accordance with previous data obtained by genomic in situ hybridization and fluorescent banding, suggesting a clear differentiation in the repeat sequence composition of both sex chromosomes between Triatomini and Rhodniini tribes. These results also support that each sex chromosome in Triatomini has evolved independently from different autosomal pairs of a common ancestor, as described in other insect orders.
Clinical and Experimental Immunology, Jun 1, 2007
We have investigated the possible role of the metabolism of tryptophan and activity of the enzyme... more We have investigated the possible role of the metabolism of tryptophan and activity of the enzyme indoleamine 2,3-dioxygenase (IDO) in the immune regulation of coeliac disease (CD). Serum concentrations of tryptophan and its metabolites kinurenines were determined by high performance liquid chromatography in 24 patients with CD, seven patients with Crohn's disease and five healthy patients. We detected an increase of kynurenine (4·2 mmol/l Ϯ 0·27 versus 2·6 mmol/l Ϯ 0·54, P < 0002) and of the kynurenine/tryptophan ratio in supernatants of coeliac patients (11·5 mmol/ l Ϯ 1·01 versus 6·5 mmol/l Ϯ 1·57, P < 0005) in comparison with healthy patients, respectively, and we found no differences with Crohn's disease patients. Immunohistochemistry analysis of intestinal biopsies from CD patients showed an increased expression of IDO, interferon-g, interleukin-10 and transforming growth factor-b. Our data suggest that a mechanism(s) dependent on tryptophan catabolism might regulate the immune responses in CD.
Hereditas, Aug 9, 1999
Fixed metaphase chromosomes and isolated genomic DNA of the ant Tapinoma nigerrimum were treated ... more Fixed metaphase chromosomes and isolated genomic DNA of the ant Tapinoma nigerrimum were treated with the restriction endonucleases EcoRI, Hue111 and Tru91. EcoRI and HaeIII induced a banding pattern similar to G-banding, whereas Tru9I induced a C-band-like pattern. There is only a partial accord between the action of these enzymes on isolated genomic DNA and on DNA in fixed chromosomes. Our results indicate that the presence of target sequences along the chromosomes is necessary but not sufficient to produce chromosome bands. The chromosomal organisation also seems to be important in producing longitudinal differentiation on chromosomes.
Genome, 1998
The effects of some restriction endonucleases (REs) on the nucleolar organizing regions and on th... more The effects of some restriction endonucleases (REs) on the nucleolar organizing regions and on the genes for ribosomal RNA (rDNA) were analyzed using the nucleolar organizing region of the chromosome 6 of Tapinoma nigerrimum as an experimental model, since, in accordance with previous studies, the genes for ribosomal RNA seem to be present only in this chromosome. In situ non-digestion of the nucleolar organizing region was observed when EcoRI and HindIII were used. However, very evident digestion and partial digestion respectively were observed when HaeIII and Tru9I were used. Southern blot analysis realized on naked DNA digested with the same REs and using rDNA of Drosophila melanogaster as probe showed that there are target sequences for these enzymes in the rDNA. In accordance with the results obtained, the rDNA is poor in EcoRI and HindIII sequences, contains moderate amounts of Tru9I sequences, and is rich in HaeIII sequences. All the data obtained suggest that in the nucleolar organizing region of Tapinoma nigerrimum, the major, if not the only, limiting factor affecting in situ digestion by the REs used is the presence and frequency of their specific restriction targets. Consequently, extraction of DNA from this chromosome region depends on the size of the fragments originated.Key words: chromosome banding, Formicidae, NORs, rDNA, restriction endonucleases.
Myrmecological News, Dec 30, 2010
Ants (Hymenoptera: Formicidae) constitute a diversified insect group with more than 12,000 specie... more Ants (Hymenoptera: Formicidae) constitute a diversified insect group with more than 12,000 species described. Like other hymenopterans, they are haplodiploid whereby fertilized eggs develop into diploid females (workers and queens) whereas unfertilized eggs develop into haploid males. A large number of species have been cytogenetically studied. The chromosome number is currently known for more than 750 species. All these data are summarized in this paper. Formicidae is one of the insect groups with the most variable chromosome number. The haploid chromosome numbers are known to range from n = 1 to n = 60. This chromosome diversity suggests that karyotype modifications have accompanied ant diversification. Karyotype evolution has followed chromosome-mutation processes able to change not only chromosome number but also chromosome morphology. We review the different chromosome mutations observed in ants and the possible role of such mutations in karyotype evolution in these insects, and we examine the hypotheses proposed to explain how this karyotype evolution may have occurred. Among chromosome rearrangements, Robertsonian centric fusions and fissions, besides inversions and translocations, seem to be the main processes that generate changes in ant karyotypes. Other processes altering chromosome numbers, such as polyploidy or aneuploidy, do not appear to be important in ant evolution. Ant subfamilies present different levels of variation in relation to chromosome number. The highest variation has been found in primitive subfamilies such as Ponerinae (n = 3 -60) and Myrmeciinae (n = 1 -47) whereas in less primitive subfamilies the chromosome numbers are less variable, as in Dolichoderinae (n = 5 -16), Formicinae (n = 8 -28), and Myrmicinae (n = 4 -35). Few data are available for other subfamilies. Primitive ants present not only the highest range of variation in chromosome number but also the most complex chromosome polymorphisms. In contrast, less primitive genera show lower variation in chromosome number, and generally only simple polymorphisms have been detected. We conclude with an outlook on future research avenues.
Infection, Genetics and Evolution, 2016
The hemipteran subfamily Triatominae includes 150 blood-sucking species, vectors of Chagas diseas... more The hemipteran subfamily Triatominae includes 150 blood-sucking species, vectors of Chagas disease. By far the most specious genus is Triatoma, assembled in groups, complexes and subcomplexes based on morphological similarities, geographic distribution and genetic data. However, many molecular studies questioned the species integration of several subcomplexes as monophyletic units. In triatomines, chromosomal position of major ribosomal DNA (rDNA) loci is extremely variable but seems to be species-specific and an evolutionary conserved genetic trait, so that closely related species tend to have ribosomal clusters in the same chromosomal location. Considering that the autosomal position as the ancestral character for all heteropteran species, including triatomines, we suggest that the movement of rDNA loci from autosomes to sex chromosomes rapidly established reproductive barriers between divergent lineages. We proposed that the rDNA translocation from the autosomes to the sex chromosomes restrict reproductive compatibility and eventually promote speciation processes. We analyzed the chromosomal position of 45S rDNA clusters in almost all species of the matogrossensis, rubrovaria, maculata and sordida subcomplexes. The fluorescent in situ hybridization results are discussed considering the available genetic data and we proposed new arrangements in the species that constitute each one of these subcomplexes.
INTED2016 Proceedings, 2016
Genes
Hippodamia variegata is one of the most commercialized ladybirds used for the biological control ... more Hippodamia variegata is one of the most commercialized ladybirds used for the biological control of aphid pest species in many economically important crops. This species is the first Coccinellidae whose satellitome has been studied by applying new sequencing technologies and bioinformatics tools. We found that 47% of the H. variegata genome is composed of repeated sequences. We identified 30 satellite DNA (satDNA) families with a median intragenomic divergence of 5.75% and A+T content between 45.6% and 74.7%. This species shows satDNA families with highly variable sizes although the most common size is 100–200 bp. However, we highlight the existence of a satDNA family with a repeat unit of 2 kb, the largest repeat unit described in Coleoptera. PCR amplifications for fluorescence in situ hybridization (FISH) probe generation were performed for the four most abundant satDNA families. FISH with the most abundant satDNA family as a probe shows its pericentromeric location on all chromos...
Sociobiology
A list of morphological characters to separate Iberoformica and Formica (Serviformica) (F. fusca ... more A list of morphological characters to separate Iberoformica and Formica (Serviformica) (F. fusca species group) is provided. Sexual forms of Formica gerardi Bondroit are described based on Iberian material and reinstated into the subgenus Serviformica based on genetic data and morphological characters. The status of †F.horrida Wheeler, 1915 is assessed.
Molecular Biology Reports
European Journal of Entomology
Cellular & Molecular Immunology
Genetica, Jan 25, 2018
The complete mitogenome of Talpa occidentalis, the Iberian mole, was sequenced using a combinatio... more The complete mitogenome of Talpa occidentalis, the Iberian mole, was sequenced using a combination of the Illumina and Sanger methods. The 16,962 bp genome obtained contains 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNAs, and a control region. Thirty-seven identical repetitions of a 10-nucleotide (CACACGTACG) repeat element were identified in the non-coding control region (D-loop). The number, order, and orientation of the mitochondrial genes are the same as in T. europaea, the only mitogenome published so far for this genus. These two mitogenomes differ only at the repeat element included in the control region. The phylogeny obtained for the Talpidae species using the protein-coding genes of these mitogenomes agrees with the current classification of this family.
Archivum immunologiae et therapiae experimentalis, Jan 25, 2018
Celiac disease is an autoimmune condition triggered by the ingestion of gluten, the protein fract... more Celiac disease is an autoimmune condition triggered by the ingestion of gluten, the protein fraction of wheat, barley and rye. It is not simply an intestinal disease; it is multifactorial caused by many different genetic factors acting together with non-genetic causes. Similar to other autoimmune diseases, celiac disease is a polygenic disorder for which the major histocompatibility complex locus is the most important genetic factor, and is the result of an immune response to self-antigens leading to tissue destruction and the autoantibodies production. Celiac disease exemplifies how an illness can have autoimmune-like features having to be driven by exogenous antigen and how can be reasonably considered as a model of organ-specific autoimmunity.
International journal of molecular sciences, Jan 24, 2018
Chagas disease or American trypanosomiasis affects six to seven million people worldwide, mostly ... more Chagas disease or American trypanosomiasis affects six to seven million people worldwide, mostly in Latin America. This disease is transmitted by hematophagous insects known as "kissing bugs" (Hemiptera, Triatominae), with and being the two most important vector species. Despite the fact that both species present the same diploid chromosome number (2 = 22), they have remarkable differences in their total DNA content, chromosome structure and genome organization. Variations in the DNA genome size are expected to be due to differences in the amount of repetitive DNA sequences. The genome-wide analysis revealed the existence of 42 satellite DNA families. BLAST searches of these sequences against the genome assembly revealed that only four of these satellite DNA families are shared between both species, suggesting a great differentiation between the and genomes. Fluorescence in situ hybridization (FISH) location of these repetitive DNAs in both species showed that they are dis...
Organisms Diversity & Evolution
Parasites & Vectors
Background: The analysis of the chromosomal and genome evolution in organisms with holocentric ch... more Background: The analysis of the chromosomal and genome evolution in organisms with holocentric chromosomes is restricted by the lack of primary constriction or centromere. An interesting group is the hemipteran subfamily Triatominae, vectors of Chagas disease, which affects around 6 to 7 million people worldwide. This group exhibits extensive variability in the number and chromosomal location of repeated sequences such as heterochromatin and ribosomal genes. This paper tries to reveal the significant differences of the repeated sequences among Triatoma species through the use of genomic DNA probes. Methods: We analysed the chromosomal distribution and evolution of repeated sequences in Triatoma species by genomic in situ hybridization (GISH) using genomic DNA probes from two North American Triatoma species. These genomic probes were hybridized both on their own chromosomes and on other Triatoma species from North and South America, with different amounts and chromosome location of C-heterochromatin. The results were compared with those previously described using South American Triatoma genomic probes. Results: We observed two chromosomal hybridization patterns: (i) very intense hybridization signals concentrated on specific chromosomal regions or particular chromosomes; and (ii) lower intensity hybridization signals dispersed along all chromosomes. Self-GISH on T. rubrofasciata and T. dimidiata chromosomes presented strong hybridization signals on all C-heterochromatin regions. However, when we perform genomic cross-hybridizations, only strong signals are detected on the Y chromosome, leaving the C-heterochromatic autosomal regions unmarked. Conclusions: We confirm that repeated DNA of the Y chromosome is shared among Triatoma species and probably represents an ancestral character of the Triatomini tribe. On the contrary, autosomal heterochromatic regions are constituted by species-specific DNA repeats, most probably satDNA families, suggesting that Triatoma speciation involved the amplification of diverse types of autosomal repeats. Molecular characterization of principal repetitive DNAs seems to be an appropriate approach to infer evolutionary relationships in triatomines.
PloS one, 2017
Triatoma infestans is the most important Chagas disease vector in South America. Two main evoluti... more Triatoma infestans is the most important Chagas disease vector in South America. Two main evolutionary lineages, named Andean and non-Andean, have been recognized by geographical distribution, phenetic and genetic characteristics. One of the main differences is the genomic size, varying over 30% in their haploid DNA content. Here we realize a genome wide analysis to compare the repetitive genome fraction (repeatome) between both lineages in order to identify the main repetitive DNA changes occurred during T. infestans differentiation process. RepeatExplorer analysis using Illumina reads showed that both lineages exhibit the same amount of non-repeat sequences, and that satellite DNA is by far the major component of repetitive DNA and the main responsible for the genome size differentiation between both lineages. We characterize 42 satellite DNA families, which are virtually all present in both lineages but with different amount in each lineage. Furthermore, chromosomal location of s...
The Indian journal of medical research, 2016
Insulin regulated aminopeptidase (IRAP) has been related to certain pathologies such as breast ca... more Insulin regulated aminopeptidase (IRAP) has been related to certain pathologies such as breast cancer, Alzheimer΄s disease and septic shock. IRAP is encoded by the leucyl/cystinyl aminopeptidase (LNPEP) gene. The genetic variation in the LNPEP gene has been analyzed in relation with the mortality and vasopressin clearance in septic shock. The LNPEP rs4869317 SNP (single nucleotide polymorphism) was the most significantly associated SNP with vasopressinase activity, being TT genotype associated with increased mortality. The objective of the present study was to develop a simple method to allow a quick and affordable genotyping for the rs4869317 SNP of LNPEP gene. Blood DNA samples were obtained from randomly selected healthy volunteers (n=28). A pair of primers was designed to amplify an 834 bp region of the LNPEP gene containing the rs4869317 SNP. The two alleles (T or A) were detected by digestion of the PCR products with the PacI restriction endonuclease. This enzyme only cuts the...
Comparative Cytogenetics, 2016
Citation: Pita S, Panzera F, Mora P, Vela J, Palomeque T, Lorite P (2016) The presence of the anc... more Citation: Pita S, Panzera F, Mora P, Vela J, Palomeque T, Lorite P (2016) The presence of the ancestral insect telomeric motif in kissing bugs (Triatominae) rules out the hypothesis of its loss in evolutionarily advanced Heteroptera Abstract Next-generation sequencing data analysis on Triatoma infestans Klug, 1834 (Heteroptera, Cimicomorpha, Reduviidae) revealed the presence of the ancestral insect (TTAGG) n telomeric motif in its genome. Fluorescence in situ hybridization confirms that chromosomes bear this telomeric sequence in their chromosomal ends. Furthermore, motif amount estimation was about 0.03% of the total genome, so that the average telomere length in each chromosomal end is almost 18 kb long. We also detected the presence of (TTAGG) n telomeric repeat in mitotic and meiotic chromosomes in other three species of Triatominae: Triatoma dimidiata Latreille, 1811, Dipetalogaster maxima Uhler, 1894, and Rhodnius prolixus Ståhl, 1859. This is the first report of the (TTAGG) n telomeric repeat in the infraorder Cimicomorpha, contradicting the currently accepted hypothesis that evolutionarily recent heteropterans lack this ancestral insect telomeric sequence.
Journal of Medical Entomology, 2016
In order to provide a broad picture on the origin and evolution of holocentric X chromosomes in h... more In order to provide a broad picture on the origin and evolution of holocentric X chromosomes in heteropteran species, we prepared a sex chromosome painting probe by microdissection of the X1 and X2 chromosomes from a kissing bug Mepraia spinolai (Hemiptera: Reduviidae: Triatominae). Fluorescence in situ hybridization on four species of the Triatomini having different amounts of autosomal heterochromatin and sex chromosome systems show that the Xs probe hybridizes on the euchromatin, located both on autosomes and X chromosomes. The heterochromatic Y chromosome and autosomal heterochromatic regions always appear free of hybridization signals. The hybridization results of the Xs probe on Rhodnius prolixus (Rhodniini) is completely different to that observed in Triatomini species. The hybridization signals are small and scattered on all euchromatin, without specific regions including the X chromosome. These results are in accordance with previous data obtained by genomic in situ hybridization and fluorescent banding, suggesting a clear differentiation in the repeat sequence composition of both sex chromosomes between Triatomini and Rhodniini tribes. These results also support that each sex chromosome in Triatomini has evolved independently from different autosomal pairs of a common ancestor, as described in other insect orders.
Clinical and Experimental Immunology, Jun 1, 2007
We have investigated the possible role of the metabolism of tryptophan and activity of the enzyme... more We have investigated the possible role of the metabolism of tryptophan and activity of the enzyme indoleamine 2,3-dioxygenase (IDO) in the immune regulation of coeliac disease (CD). Serum concentrations of tryptophan and its metabolites kinurenines were determined by high performance liquid chromatography in 24 patients with CD, seven patients with Crohn's disease and five healthy patients. We detected an increase of kynurenine (4·2 mmol/l Ϯ 0·27 versus 2·6 mmol/l Ϯ 0·54, P < 0002) and of the kynurenine/tryptophan ratio in supernatants of coeliac patients (11·5 mmol/ l Ϯ 1·01 versus 6·5 mmol/l Ϯ 1·57, P < 0005) in comparison with healthy patients, respectively, and we found no differences with Crohn's disease patients. Immunohistochemistry analysis of intestinal biopsies from CD patients showed an increased expression of IDO, interferon-g, interleukin-10 and transforming growth factor-b. Our data suggest that a mechanism(s) dependent on tryptophan catabolism might regulate the immune responses in CD.
Hereditas, Aug 9, 1999
Fixed metaphase chromosomes and isolated genomic DNA of the ant Tapinoma nigerrimum were treated ... more Fixed metaphase chromosomes and isolated genomic DNA of the ant Tapinoma nigerrimum were treated with the restriction endonucleases EcoRI, Hue111 and Tru91. EcoRI and HaeIII induced a banding pattern similar to G-banding, whereas Tru9I induced a C-band-like pattern. There is only a partial accord between the action of these enzymes on isolated genomic DNA and on DNA in fixed chromosomes. Our results indicate that the presence of target sequences along the chromosomes is necessary but not sufficient to produce chromosome bands. The chromosomal organisation also seems to be important in producing longitudinal differentiation on chromosomes.
Genome, 1998
The effects of some restriction endonucleases (REs) on the nucleolar organizing regions and on th... more The effects of some restriction endonucleases (REs) on the nucleolar organizing regions and on the genes for ribosomal RNA (rDNA) were analyzed using the nucleolar organizing region of the chromosome 6 of Tapinoma nigerrimum as an experimental model, since, in accordance with previous studies, the genes for ribosomal RNA seem to be present only in this chromosome. In situ non-digestion of the nucleolar organizing region was observed when EcoRI and HindIII were used. However, very evident digestion and partial digestion respectively were observed when HaeIII and Tru9I were used. Southern blot analysis realized on naked DNA digested with the same REs and using rDNA of Drosophila melanogaster as probe showed that there are target sequences for these enzymes in the rDNA. In accordance with the results obtained, the rDNA is poor in EcoRI and HindIII sequences, contains moderate amounts of Tru9I sequences, and is rich in HaeIII sequences. All the data obtained suggest that in the nucleolar organizing region of Tapinoma nigerrimum, the major, if not the only, limiting factor affecting in situ digestion by the REs used is the presence and frequency of their specific restriction targets. Consequently, extraction of DNA from this chromosome region depends on the size of the fragments originated.Key words: chromosome banding, Formicidae, NORs, rDNA, restriction endonucleases.
Myrmecological News, Dec 30, 2010
Ants (Hymenoptera: Formicidae) constitute a diversified insect group with more than 12,000 specie... more Ants (Hymenoptera: Formicidae) constitute a diversified insect group with more than 12,000 species described. Like other hymenopterans, they are haplodiploid whereby fertilized eggs develop into diploid females (workers and queens) whereas unfertilized eggs develop into haploid males. A large number of species have been cytogenetically studied. The chromosome number is currently known for more than 750 species. All these data are summarized in this paper. Formicidae is one of the insect groups with the most variable chromosome number. The haploid chromosome numbers are known to range from n = 1 to n = 60. This chromosome diversity suggests that karyotype modifications have accompanied ant diversification. Karyotype evolution has followed chromosome-mutation processes able to change not only chromosome number but also chromosome morphology. We review the different chromosome mutations observed in ants and the possible role of such mutations in karyotype evolution in these insects, and we examine the hypotheses proposed to explain how this karyotype evolution may have occurred. Among chromosome rearrangements, Robertsonian centric fusions and fissions, besides inversions and translocations, seem to be the main processes that generate changes in ant karyotypes. Other processes altering chromosome numbers, such as polyploidy or aneuploidy, do not appear to be important in ant evolution. Ant subfamilies present different levels of variation in relation to chromosome number. The highest variation has been found in primitive subfamilies such as Ponerinae (n = 3 -60) and Myrmeciinae (n = 1 -47) whereas in less primitive subfamilies the chromosome numbers are less variable, as in Dolichoderinae (n = 5 -16), Formicinae (n = 8 -28), and Myrmicinae (n = 4 -35). Few data are available for other subfamilies. Primitive ants present not only the highest range of variation in chromosome number but also the most complex chromosome polymorphisms. In contrast, less primitive genera show lower variation in chromosome number, and generally only simple polymorphisms have been detected. We conclude with an outlook on future research avenues.
Infection, Genetics and Evolution, 2016
The hemipteran subfamily Triatominae includes 150 blood-sucking species, vectors of Chagas diseas... more The hemipteran subfamily Triatominae includes 150 blood-sucking species, vectors of Chagas disease. By far the most specious genus is Triatoma, assembled in groups, complexes and subcomplexes based on morphological similarities, geographic distribution and genetic data. However, many molecular studies questioned the species integration of several subcomplexes as monophyletic units. In triatomines, chromosomal position of major ribosomal DNA (rDNA) loci is extremely variable but seems to be species-specific and an evolutionary conserved genetic trait, so that closely related species tend to have ribosomal clusters in the same chromosomal location. Considering that the autosomal position as the ancestral character for all heteropteran species, including triatomines, we suggest that the movement of rDNA loci from autosomes to sex chromosomes rapidly established reproductive barriers between divergent lineages. We proposed that the rDNA translocation from the autosomes to the sex chromosomes restrict reproductive compatibility and eventually promote speciation processes. We analyzed the chromosomal position of 45S rDNA clusters in almost all species of the matogrossensis, rubrovaria, maculata and sordida subcomplexes. The fluorescent in situ hybridization results are discussed considering the available genetic data and we proposed new arrangements in the species that constitute each one of these subcomplexes.
INTED2016 Proceedings, 2016