Genetic diversity and relatedness between Canindé and British Alpine goat breeds in Northeastern Brazil accessed by microsatellite markers.

The aim of this study was to access the genetic diversity and relatedness between Canindé and British Alpine goat breeds in the States of Piauí and Ceará using microsatellite markers. Genomic DNA was isolated from hair samples of 99 goats belonging to six different flocks. A panel of polymorphic heterologous microsatellite loci was used to genotype individuals. The microsatellite markers resulted in a total number of 145 alleles, with an average of 8.5 alleles per locus. The observed and expected heterozygosities were ≥0.687 and ≥0.627, respectively, for all loci. The polymorphic information content showed that all loci were highly informative with an overall mean of 0.757. Overall FST across all populations and loci was 18%, which was consistent with the coefficient of gene differentiation (GST = 0.104). AMOVA revealed that 12.8% of the variation was captured between breeds. The Bayesian STRUCTURE clustering detected the maximum likelihood for a model of two genetically distinct groups, in agreement with the number of predefined studied breeds and the two-dimensional plot from the PCoA analysis. The exotic British Alpine breed and the naturalized Brazilian Canindé breed were clearly differentiated by the microsatellite markers, indicating that these two breeds have distant genetic identities, despite the phenotypic similarity.

Development of novel simple sequence repeat markers from a genomic sequence survey database and their application for diversity assessment in Jatropha curcas germplasm from Guatemala.

The last few years have seen a significant increase in the number of large-scale sequencing projects generating whole genome databases. These sequence databases can be surveyed (genome sequence survey) for tandem repeats as an alternative means to develop microsatellites for monitoring and selecting natural populations and cultivars of Jatropha curcas. A total of 100 tandem repeats were revealed from mining 368 genomic surveyed sequences available in the Kazusa DNA Research Institute database. Twenty microsatellite sequences were successfully amplified, resulting in repeatable and scorable polymerase chain reaction products. Genotyping of J. curcas accessions from the Guatemalan population revealed 18 polymorphic loci. The average number of alleles per locus was 6.9, and allelic sizes ranged from 94 to 299 bp. Expected and observed heterozygosities ranged from 0.118 to 0.906 and from 0.082 to 0.794, respectively. Polymorphic information content values ranged from 0.114 (JcSSR-34) to 0.886 (JcSSR-33) with an average of 0.627. Analysis with Micro-Checker indicated few null alleles for locus JcSSR-37 in Guatemalan populations, which may be a possible cause of its deviation from Hardy-Weinberg equilibrium, even after Bonferroni's correction. No loci showed significant linkage disequilibrium. These microsatellite loci are expected to be valuable molecular markers in J. curcas because they show high levels of polymorphism and heterozygosity.

Single primer-based DNA amplification as a suitable and low-cost tool for assessing genetic diversity in mangrove crabs.

We used single primer-based DNA markers to assess genetic variability of the mangrove crab, Ucides cordatus, collected from four different localities from Pará to Santa Catarina States in Brazil (almost 5000 km distant). Five primers were chosen based on the consistency of the amplified bands and the polymorphism of each locus. A total of 78 loci were amplified in 76 samples; high polymorphism rates were detected in the entire sample (80.8%) and within each locality (73.5-79.5%). Analysis of molecular variance demonstrates significant differences between localities (P < 0.001); however, the Φ(ST) value (0.078) indicates a low level of genetic differentiation, which suggests that U. cordatus larvae can spread over large distances. The variation was distributed among the samples, and most of it was attributed to differences among individuals within localities. Cluster analysis, based on the Jaccard similarity coefficient, and the Mantel test gave similar results to the analysis of molecular variance data. Despite the low level of population structuring, these markers could be used for studying U. cordatus diversity, due to the high level of polymorphism.

Remnants of ancient genetic diversity preserved within captive groups of scimitar-horned oryx (Oryx dammah).

Scimitar-horned oryx, now considered extinct in the wild, persists in large numbers in captivity. In this first molecular genetic study on this species, we explore the patterns of genetic diversity across European, North American, and a few other captive groups using microsatellite markers and mitochondrial control region sequencing. Strong population structure was not evident from microsatellite data but we discovered deep divergence within the mitochondrial DNA haplotypes from a network analysis where three disconnected networks were obtained, with estimated divergence times of c. 2.1-2.7 million years. Mismatch distribution analyses suggest population expansions c. 1.2 and 0.5 million years ago. We discuss our findings in the context of historical climatic changes in North Africa and use information obtained on current patterns of genetic diversity within captive groups to make recommendations for future captive management and reintroduction strategies.

Optimization of nitrogen recovery in the enzymatic hydrolysis of dogfish (Squalus acanthias) protein. Composition of the hydrolysates.

The recovery of nitrogen in the enzymatic hydrolysis of dogfish shark muscle was optimized by the use of response surface methodology. The optimum values for enzyme/substrate ratio, temperature and pH were found to be 3.7% (w/w), 55.3 degrees C, and 8.3, respectively. The dogfish protein hydrolysate produced under these conditions contained a high crude protein concentration (> 85%), and its high nutritional value was indicated by the presence of all essential amino acids, and by high PER values. These results indicate the potential for dogfish protein hydrolysate to be used in lieu of vegetable proteins as a protein supplement in foods.