Further characterization of nuclear DNA RFLP markers that distinguish African and European honeybees

Two nuclear honeybee DNA probes, 12R1C1 and 2A2, were reported previously to detect restriction fragment patterns specific to African and neotropical African honeybee populations. Individual drones and workers from several additional Old and New World populations, African and European, were tested further with these probes. With probe 12R1C1, only two of several Hhal fragment patterns were seen among haploid drone progeny of each queen bee, indicating that the patterns represented alleles at a single locus. Four alleles detected by probe 12R1C1 were described previously, three of which had been found only in populations of African descent. In this study, one of the three was found at a low frequency among samples from western Europe, northern Mexico, and the United States. However, ten additional alleles were discovered in South African drones, six of which were seen also in neotropical African colonies. With probe 2A2, only one or the other of two Alul restriction fragments was detected in drones indicating that the fragments represented alles at a single locus. One of the two alleles, seen previously only in populations of African descent, was found at a very low frequency in bees from western Europe and northern Mexico.     

Diffusion approximations of the two-locus Wright-Fisher model

Diffusion approximations are established for the multiallelic, two-locus Wright-Fisher model for mutation, selection, and random genetic drift in a finite, panmictic, monoecious, diploid population. All four combinations of weak or strong selection and tight or loose linkage are treated, though the proof in the case of strong selection and loose linkage is incomplete. Under certain conditions, explicit formulas are obtained for the stationary distributions of the two diffusions with loose linkage.Supported in part by NSF Grant DMS-8704369Supported in part by NSF Grant BSR-8512844     

Frequencies of plasma protease inhibitor alleles in Australian horse breeds and the recognition of two new alleles

Investigation of the plasma protease inhibitor system (Pi) in the Arabian and quarter horse breeds and re-examination of the standardbred breed resulted in the recognition of two new Pi alleles, designated E and L2. PiE is rare and has been found in only three quarter horses. In contrast, PiL2 is relatively common in the standardbred (0.107) and allowed subdivision of PiL into PiL and PiL2. Splitting of PiL resulted in an exclusion probability (PE) of 0.649 for the standardbred Pi system. Frequencies of the Pi genes have now been determined for four breeds (thoroughbred, standardbred, quarter horse and Arabian) of horses in Australia.