Marlise Bartholomei-Santos | UFSM - Universidade Federal de Santa Maria (original) (raw)

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Papers by Marlise Bartholomei-Santos

Research paper thumbnail of ESTIMULANDO O “PENSAMENTO EM ÁRVORE” EM ALUNOS DE ENSINO MÉDIO: POTENCIAL DE CONTRIBUIÇÃO DOS LIVROS DIDÁTICOS DE BIOLOGIA

Research paper thumbnail of New species and records of the genus Aegla Leach, 1820 (Crustacea, Anomura, Aeglidae) from the West-Central region of Rio Grande do Sul, Brazil

Research paper thumbnail of Detection of genetic polymorphism among and within Echinococcus granulosus strains by heteroduplex analysis of a microsatellite from the U1 snRNA genes

Genetics and Molecular Research 5 (3): 542-552 (2006) FUNPEC-RP www.funpecrp.com.br Heteroduplex... more Genetics and Molecular Research 5 (3): 542-552 (2006) FUNPEC-RP www.funpecrp.com.br Heteroduplex analysis of the U1 snRNA gene in E. granulosus 543 Genetics and Molecular Research 5 (3): 542-552 (2006) www.funpecrp.com.br manian sheep, cattle, and camel strains. The former two showed polymorphism and shared three of the six patterns found for sheep strain.

Research paper thumbnail of GENÉTICA E SUAS APLICAÇÕES: IDENTIFICANDO O CONHECIMENTO PRESENTE ENTRE CONCLUINTES DO ENSINO MÉDIO

Research paper thumbnail of The DNA Barcoding and the Caveats with Respect to Its Application to Some Species of Palaemonidae (Crustacea, Decapoda)

Zoological Science, 2012

DNA-barcoding has recently attracted considerable attention due to its potential utility in aidin... more DNA-barcoding has recently attracted considerable attention due to its potential utility in aiding in species identification and discovery through the use of a short standardized sequence of mitochondrial DNA. Nevertheless, despite the fact that this technology has been proven a useful tool in several animal taxa, it also demonstrated limitations that may hinder correct application. Thus, its validity needs to be empirically evaluated in each taxonomic category before forward implementation. As the use of DNA barcoding within Palaemonidae may be of special interest, given its great interspecific morphological conservatism associated with considerable intraspecific morphological variation, we analyze here the potential of this technology in distinguishing and recovering some taxonomic boundaries within this family. We asked whether two GenBank-retrieved sets of COI sequences encompassing the conventional Barcode and Jerry-Pat regions possess the desired properties of reciprocal monophyly among species, and existence of a barcoding gap between intra- and interspecific variations, after performing a careful analysis of numt (nuclear mitochondrial DNA) contamination. These analyses revealed nine non-monophyletic species, with some cases of divergent intraspecific sequences, contrasted with interspecific similarity attained in others. Moreover, we were unable to identify any barcoding gap between intraspecific and interspecific divergences within Palaemonidae, although a threshold of 0.18 substitutions per site would differentiate intraspecific and congeneric divergences in 95% of the cases for the barcoding region. A fraction of the overlap could be certainly attributed to artifacts related to poor taxonomy, but even from this perspective DNA barcoding studies may help to uncover previously disregarded taxonomic and evolutionary issues.

Research paper thumbnail of Comparison of different methodologies for DNA extraction from Aegla longirostri

Brazilian Archives of Biology and Technology, 2007

The aim of this study was to compare some DNA extraction methodologies for Aegla longirostri. The... more The aim of this study was to compare some DNA extraction methodologies for Aegla longirostri. The protocols were based on the traditional phenol-chloroform DNA extraction methodology and using a commercial kit for DNA extraction. They differed in tissues used, the addition – or not – of b-mercaptoethanol to the lysis buffer, times and methods for the animal's conservation (frozen, in ethanol or fresh). Individuals stored at –20°C for a long time supplied lower molecular weight DNA than those stored for a short time. The best yield for the specimens preserved in ethanol was obtained for 15 days storage in 95% ethanol. The kit resulted in a low quantity of high molecular weight DNA. The best protocol for DNA extraction from Aeglidae, and probably for other crustaceans should, therefore, utilize fresh specimens, with addition of b-mercaptoethanol to the lysis buffer.

Research paper thumbnail of High genetic differentiation of Aegla longirostri (Crustacea, Decapoda, Anomura) populations in southern Brazil revealed by multi-loci microsatellite analysis

Genetics and Molecular Research, 2011

Species with a broad distribution rarely have the same genetic make-up throughout their entire ra... more Species with a broad distribution rarely have the same genetic make-up throughout their entire range. In some cases, they may constitute a cryptic complex consisting of a few species, each with a narrow distribution, instead of a single-, widely distributed species. These differences can have profound impacts for biodiversity conservation planning. The genetic differentiation of four populations of Aegla longirostri, a freshwater crab found in two geographically isolated basins in Rio Grande do Sul State, Brazil, was investigated by analyzing pentanucleotide multi-loci microsatellites in a heteroduplex assay. Although no morphological differences were evident, we found significant genetic differentiation among the four populations, based on F(ST) values and clustering analysis. This high level of differentiation may be indicative of cryptic species in these populations. If this hypothesis is correct, then the species occurring in the Ibicuí-Mirim River, at the southern limit of the Atlantic Rain Forest, would be under threat, considering its very restricted distribution.

Research paper thumbnail of PCR-mediated recombination in development of microsatellite markers: mechanism and implications

Genetics and Molecular Biology, 2008

Protocols for microsatellite-enrichment libraries have been widely applied to several species in ... more Protocols for microsatellite-enrichment libraries have been widely applied to several species in order to supply the most informative molecular markers for population and inbreeding studies. One drawback of these protocols is the ratio of designed primer pairs that fail to amplify the expected fragment, even after exhaustive optimization attempts. A possible cause of unsuccessful microsatellite primers may be that such loci are artifacts resulting from chimeric PCR products, instead of real genomic sequences. The microsatellite-enriched library constructed for Aegla longirostri (Crustacea, Decapoda, Anomura) showed that 29% of sequenced clones were chimeric products because these sequences shared one of the flanking regions around the same repeat motif but not the other. PCR-mediated recombination is a well-known event described for several procedures in which related sequences are used as a template. We have associated this phenomenon with microsatellite marker development. This study explained the high ratio of recombinant sequences generated in the A. longirostri microsatellite-enriched library. We discuss the mechanism and implications of PCR chimeric-product formation during microsatellite isolation.

Research paper thumbnail of Chromosome sensitivity to bleomycin in G2 lymphocytes from Down syndrome patients

Brazilian Journal of Genetics, 1997

Research paper thumbnail of Tetranucleotide microsatellite markers in Ctenomys torquatus (Rodentia)

Conservation Genetics Resources, 2011

Eleven microsatellite markers were isolated from an enriched library developed specifically for t... more Eleven microsatellite markers were isolated from an enriched library developed specifically for the tuco-tuco Ctenomys torquatus, using tri and tetranucleotide probes. Ten of these were successfully amplified, and only one was monomorphic for the populations that have so far been analyzed. Analysis of two different populations yielded a mean of 2.6 (Cachoeira do Sul-CAC) and 4.3 (Butiá-BUT) alleles per locus, with a range from 1 to 6. The means for observed and expected heterozygosity were also lower in the CAC population (Ho = 0.37 and He = 0.39), but in BUT they were 0.63 and 0.61 respectively. These are the first microsatellite markers reported for a Brazilian species of tuco-tuco, and will be applied to investigate the genetic structure of their populations in the widely impacted Pampa Biome.

Research paper thumbnail of Intraspecific variation in A egla longirostri (Crustacea: Decapoda: Anomura) revealed by geometric morphometrics: evidence for ongoing speciation?

Biological Journal of the Linnean Society, 2014

Genetic divergences among populations of Aegla longirostri suggest that this group may be formed ... more Genetic divergences among populations of Aegla longirostri suggest that this group may be formed by cryptic species. In this study, we analysed the carapace shape of six populations of A. longirostri from southern Brazil, using a geometric morphometric approach, to better elucidate the species' systematics. Our results were congruent with the genetic data, meaning that genetically differentiated populations were also morphogeometrically differentiated. The geometric morphometric descriptors showed significant differences in carapace shape among all populations. Geographical distance and isolation may be affecting the gene flow between populations, leading to divergence in both genetic and morphometric traits. Our data indicate the possible existence of cryptic species within A. longirostri, or an incomplete process of speciation. Geometric morphometric methods were efficient in differentiating among populations that do not show divergence in diagnostic characters.

Research paper thumbnail of ESTIMULANDO O “PENSAMENTO EM ÁRVORE” EM ALUNOS DE ENSINO MÉDIO: POTENCIAL DE CONTRIBUIÇÃO DOS LIVROS DIDÁTICOS DE BIOLOGIA

Research paper thumbnail of New species and records of the genus Aegla Leach, 1820 (Crustacea, Anomura, Aeglidae) from the West-Central region of Rio Grande do Sul, Brazil

Research paper thumbnail of Detection of genetic polymorphism among and within Echinococcus granulosus strains by heteroduplex analysis of a microsatellite from the U1 snRNA genes

Genetics and Molecular Research 5 (3): 542-552 (2006) FUNPEC-RP www.funpecrp.com.br Heteroduplex... more Genetics and Molecular Research 5 (3): 542-552 (2006) FUNPEC-RP www.funpecrp.com.br Heteroduplex analysis of the U1 snRNA gene in E. granulosus 543 Genetics and Molecular Research 5 (3): 542-552 (2006) www.funpecrp.com.br manian sheep, cattle, and camel strains. The former two showed polymorphism and shared three of the six patterns found for sheep strain.

Research paper thumbnail of GENÉTICA E SUAS APLICAÇÕES: IDENTIFICANDO O CONHECIMENTO PRESENTE ENTRE CONCLUINTES DO ENSINO MÉDIO

Research paper thumbnail of The DNA Barcoding and the Caveats with Respect to Its Application to Some Species of Palaemonidae (Crustacea, Decapoda)

Zoological Science, 2012

DNA-barcoding has recently attracted considerable attention due to its potential utility in aidin... more DNA-barcoding has recently attracted considerable attention due to its potential utility in aiding in species identification and discovery through the use of a short standardized sequence of mitochondrial DNA. Nevertheless, despite the fact that this technology has been proven a useful tool in several animal taxa, it also demonstrated limitations that may hinder correct application. Thus, its validity needs to be empirically evaluated in each taxonomic category before forward implementation. As the use of DNA barcoding within Palaemonidae may be of special interest, given its great interspecific morphological conservatism associated with considerable intraspecific morphological variation, we analyze here the potential of this technology in distinguishing and recovering some taxonomic boundaries within this family. We asked whether two GenBank-retrieved sets of COI sequences encompassing the conventional Barcode and Jerry-Pat regions possess the desired properties of reciprocal monophyly among species, and existence of a barcoding gap between intra- and interspecific variations, after performing a careful analysis of numt (nuclear mitochondrial DNA) contamination. These analyses revealed nine non-monophyletic species, with some cases of divergent intraspecific sequences, contrasted with interspecific similarity attained in others. Moreover, we were unable to identify any barcoding gap between intraspecific and interspecific divergences within Palaemonidae, although a threshold of 0.18 substitutions per site would differentiate intraspecific and congeneric divergences in 95% of the cases for the barcoding region. A fraction of the overlap could be certainly attributed to artifacts related to poor taxonomy, but even from this perspective DNA barcoding studies may help to uncover previously disregarded taxonomic and evolutionary issues.

Research paper thumbnail of Comparison of different methodologies for DNA extraction from Aegla longirostri

Brazilian Archives of Biology and Technology, 2007

The aim of this study was to compare some DNA extraction methodologies for Aegla longirostri. The... more The aim of this study was to compare some DNA extraction methodologies for Aegla longirostri. The protocols were based on the traditional phenol-chloroform DNA extraction methodology and using a commercial kit for DNA extraction. They differed in tissues used, the addition – or not – of b-mercaptoethanol to the lysis buffer, times and methods for the animal's conservation (frozen, in ethanol or fresh). Individuals stored at –20°C for a long time supplied lower molecular weight DNA than those stored for a short time. The best yield for the specimens preserved in ethanol was obtained for 15 days storage in 95% ethanol. The kit resulted in a low quantity of high molecular weight DNA. The best protocol for DNA extraction from Aeglidae, and probably for other crustaceans should, therefore, utilize fresh specimens, with addition of b-mercaptoethanol to the lysis buffer.

Research paper thumbnail of High genetic differentiation of Aegla longirostri (Crustacea, Decapoda, Anomura) populations in southern Brazil revealed by multi-loci microsatellite analysis

Genetics and Molecular Research, 2011

Species with a broad distribution rarely have the same genetic make-up throughout their entire ra... more Species with a broad distribution rarely have the same genetic make-up throughout their entire range. In some cases, they may constitute a cryptic complex consisting of a few species, each with a narrow distribution, instead of a single-, widely distributed species. These differences can have profound impacts for biodiversity conservation planning. The genetic differentiation of four populations of Aegla longirostri, a freshwater crab found in two geographically isolated basins in Rio Grande do Sul State, Brazil, was investigated by analyzing pentanucleotide multi-loci microsatellites in a heteroduplex assay. Although no morphological differences were evident, we found significant genetic differentiation among the four populations, based on F(ST) values and clustering analysis. This high level of differentiation may be indicative of cryptic species in these populations. If this hypothesis is correct, then the species occurring in the Ibicuí-Mirim River, at the southern limit of the Atlantic Rain Forest, would be under threat, considering its very restricted distribution.

Research paper thumbnail of PCR-mediated recombination in development of microsatellite markers: mechanism and implications

Genetics and Molecular Biology, 2008

Protocols for microsatellite-enrichment libraries have been widely applied to several species in ... more Protocols for microsatellite-enrichment libraries have been widely applied to several species in order to supply the most informative molecular markers for population and inbreeding studies. One drawback of these protocols is the ratio of designed primer pairs that fail to amplify the expected fragment, even after exhaustive optimization attempts. A possible cause of unsuccessful microsatellite primers may be that such loci are artifacts resulting from chimeric PCR products, instead of real genomic sequences. The microsatellite-enriched library constructed for Aegla longirostri (Crustacea, Decapoda, Anomura) showed that 29% of sequenced clones were chimeric products because these sequences shared one of the flanking regions around the same repeat motif but not the other. PCR-mediated recombination is a well-known event described for several procedures in which related sequences are used as a template. We have associated this phenomenon with microsatellite marker development. This study explained the high ratio of recombinant sequences generated in the A. longirostri microsatellite-enriched library. We discuss the mechanism and implications of PCR chimeric-product formation during microsatellite isolation.

Research paper thumbnail of Chromosome sensitivity to bleomycin in G2 lymphocytes from Down syndrome patients

Brazilian Journal of Genetics, 1997

Research paper thumbnail of Tetranucleotide microsatellite markers in Ctenomys torquatus (Rodentia)

Conservation Genetics Resources, 2011

Eleven microsatellite markers were isolated from an enriched library developed specifically for t... more Eleven microsatellite markers were isolated from an enriched library developed specifically for the tuco-tuco Ctenomys torquatus, using tri and tetranucleotide probes. Ten of these were successfully amplified, and only one was monomorphic for the populations that have so far been analyzed. Analysis of two different populations yielded a mean of 2.6 (Cachoeira do Sul-CAC) and 4.3 (Butiá-BUT) alleles per locus, with a range from 1 to 6. The means for observed and expected heterozygosity were also lower in the CAC population (Ho = 0.37 and He = 0.39), but in BUT they were 0.63 and 0.61 respectively. These are the first microsatellite markers reported for a Brazilian species of tuco-tuco, and will be applied to investigate the genetic structure of their populations in the widely impacted Pampa Biome.

Research paper thumbnail of Intraspecific variation in A egla longirostri (Crustacea: Decapoda: Anomura) revealed by geometric morphometrics: evidence for ongoing speciation?

Biological Journal of the Linnean Society, 2014

Genetic divergences among populations of Aegla longirostri suggest that this group may be formed ... more Genetic divergences among populations of Aegla longirostri suggest that this group may be formed by cryptic species. In this study, we analysed the carapace shape of six populations of A. longirostri from southern Brazil, using a geometric morphometric approach, to better elucidate the species' systematics. Our results were congruent with the genetic data, meaning that genetically differentiated populations were also morphogeometrically differentiated. The geometric morphometric descriptors showed significant differences in carapace shape among all populations. Geographical distance and isolation may be affecting the gene flow between populations, leading to divergence in both genetic and morphometric traits. Our data indicate the possible existence of cryptic species within A. longirostri, or an incomplete process of speciation. Geometric morphometric methods were efficient in differentiating among populations that do not show divergence in diagnostic characters.