Conservation genetics of neotropical pollinators revisited: microsatellite analysis suggests that diploid males are rare in orchid bees.

Allozyme analyses have suggested that Neotropical orchid bee (Euglossini) pollinators are vulnerable because of putative high frequencies of diploid males, a result of loss of sex allele diversity in small hymenopteran populations with single locus complementary sex determination. Our analysis of 1010 males from 27 species of euglossine bees sampled across the Neotropics at 2­11 polymorphic microsatellite loci revealed only five diploid males at an overall frequency of 0.005 (95% CIs 0.002­0.010); errors through genetic nondetection of diploid males were likely small. In contrast to allozyme-based studies, we detected very weak or insignificant population genetic structure, even for a pair of populations >500 km apart, possibly accounting for low diploid male frequencies. Technical flaws in previous allozyme-based analyses have probably led to considerable overestimation of diploid male production in orchid bees. Other factors may have a more immediate impact on population persistence than the genetic load imposed by diploid males on these important Neotropical pollinators.

Genetic variability of 10 microsatellite markers in the characterization of Brazilian Nellore cattle (Bos indicus)

We assessed the polymorphism of 10 microsatellites in Brazilian Nellore cattle (Bos indicus) using a commercial multiplex system. Allele frequencies, polymorphism information content, heterozygosity and exclusion probability were calculated. Allele frequencies revealed that in the sample analyzed the markers were not equally polymorphic. The exclusion probabilities and the polymorphism information content of some loci in Nellore cattle were lower than in Bos taurus breeds. When all the microsatellites were considered the combined exclusion probability was 0.9989. This multiplex analysis can contribute toward pedigree information, adequate genetic improvements and breeding programs.

Studies of blood groups and protein polymorphisms in the Brazilian horse breeds Mangalarga Marchador and Mangalarga (Equus caballus)

Allelic frequencies at 12 loci (five blood groups: C, D, K, P, and U; and seven protein polymorphisms: Al, A1B, Es, Gc, Hb, PGD, and Tf), are given for two Brazilian horse breeds: Mangalarga Marchador and Mangalarga. The high genetic identity value found (96.0 percent) is consistent with their common origin, although, at some point of the development of Mangalarga Marchador, Mangalarga separated from the original stock. The expected average heterozygosity was higher in Mangalarga Marchador. The populations presented genetic differentiation, as shown by the statistically significant value of F ST. The nonsignificant F IS values showed that there was no appreciable consanguineous mating in any of the two populations. Exclusion probability calculated for the 12 loci was 87.0 percent and 86.5 percent for Mangalarga Marchador and Mangalarga, respectively. No genetic equilibrium was observed in the A1B, Tf, and Es loci of Mangalarga Marchador. The frequencies of blood factors A, Q, and T were calculated.