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- Microsatellite variability in natural populations of the blackspot seabream Pagellus bogaraveo (Brunnick, 1768): a database to access parentage assignment in aquaculturePublication . Lemos, Andreia; Freitas, Ana Isabel; Fernandes, Ana Teresa; Gonçalves, Rita; Jesus, José; Andrade, Carlos; Brehm, AntónioEight microsatellite loci previously reported were as sessed for their utility in parentage assignment in 96 individuals belonging to natural populations of the blackspot seabream Pagellus bogaraveo (Brˇnnick, 1768) from the Mediterranean and Northeast Atlantic regions. At the mtDNA level, no di¡erentiation was found between these two regions but based on micro satellite data an overall discrete genetic di¡erentiation is perceivable between the two regions separated by the Strait of Gibraltar. The number of alleles per locus ranged from 8 to 30. A database constructed with al lele frequency data from six populations was used in a simulation parentage assignment test using the software CERVUS. The test showed that the number of markers used is enough to perform parentage assign ments with real data. The polymorphic information content for each locus was very high (mean value of 0.849), with a total exclusionary power of 0.9995. In summary, seven of the eight microsatellites analysed proved to be su⁄cient and powerful tools for parent age assignment in hatcheries and the allele frequency data given here can be used to perform pedigree ana lysis against which real data may be tested.
- Y-chromosomal STRs in two populations from Israel and the Palestinian Authority Area: Christian and Muslim ArabsPublication . Fernandes, Ana Teresa; Gonçalves, Rita; Gomes, Sara; Filon, Dvora; Nebel, Almut; Faerman, Marina; Brehm, António
- Genetic profile of a multi-ethnic population from Guiné-Bissau (west African coast) using the new PowerPlex® 16 System kitPublication . Gonçalves, Rita; Jesus, José; Fernandes, Ana Teresa; Brehm, AntónioAllele and haplotype frequencies of 15 chromosome STR loci included in the kit PowerPlex1 16 System from Promega, were determined in a sample of unrelated males from Guine´-Bissau, a country from the west African coast. All individuals were subjected to an interview in order to make sure that their ancestors belonged to the same ethnic group. This way we intended to look for possible inter-ethnic differences. PowerPlex 16 includes STRs not studied before in any multi-ethnic population. The kit includes two new allele markers (Penta D and Penta E), which are very useful either in forensics or population genetic studies. The Guinean population presents significant differences when compared with other African populations.
- DAZ gene copies: evidence of Y chromosome evolutionPublication . Fernandes, Ana Teresa; Fernandes, Susana; Gonçalves, Rita; Sá, Rosália; Costa, Paula; Rosa, Alexandra; Farrás, Cristina; Sousa, Mário; Brehm, António; Barros, AlbertoThe DAZ gene, a contributing factor in infertility, lies on the human Y chromosome's AZFc region, whose deletion is a common cause of spermatogenic failure. Y chromosome binary polymorphisms on the non-recombining Y (NRY) region, believed to be a single occurrence on an evolutionary scale, were typed in a sample of fertile and infertile men with known DAZ backgrounds. The Y single-nucleotide polymorphisms (Y-SNPs) with low mutation rates are currently well characterized and permit the construction of a unique phylogeny of haplogroups. DAZ haplotypes were defined using single-nucleotide variant (SNV)/sequence tagged-site (STS) markers to distinguish between the four copies of the gene. The variation of 10 Y chromosome short tandem repeat (STRs) was used to determine the coalescence age of DAZ haplotypes in a comparable time frame similar to that of SNP haplogroups. An association between DAZ haplotypes and Y chromosome haplogroups was found, and our data show that the DAZ gene is not under selective constraints and its evolution depends only on the mutation rate. The same variants were common to fertile and infertile men, although partial DAZ deletions occurred only in infertile men, suggesting that those should only be used as a tool for infertility diagnosis when analysed in combination with haplogroup determinations.