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Genetic drift (GD) randomly impacts small breeds and imported populations. Therefore, it can impact policies that affect conservation of animal genetic resources. This paper evaluates GD for a population of Meishan pigs imported into the United States and explores the ramifications of GD on access and benefit sharing of genetic resources under the Nagoya Protocol (NP) of the United Nations' Convention on Biological Diversity. The NP was motivated by concerns about fair and equitable benefit sharing of genetic resources across life forms. In this experiment, 35 microsatellite markers were used to quantify the level of GD that occurred between Meishan pigs (Meishan-China; n = 22) imported into the United States in the late 1980s and contemporary Meishan (Meishan-US; n = 42), which have been randomly bred since importation. The Meishan-US consisted of 2 subpopulations (Meishan-MARC and Meishan-ISU). Five other breeds were also included in the analysis to serve as reference populations: Fengjing and Minzhu, which were imported with Meishan-China, and Duroc, Berkshire, and Yorkshire from the United States. Mean shift in allele frequency was 0.11 (SE = 0.019) due to GD for Meishan-US vs. Meishan-China with some loci having changed allele frequencies by greater than 0.20. Principle coordinate analysis confirmed divergence among the Meishan populations. Model-based clustering tended to place the U.S. and Chinese breeds into 2 distinct clusters, likely due to differences in allele frequencies between U.S. and Chinese breeds. Contemporary Meishan-US has become differentiated from the original imported animals due to GD. Attributing future performance of Meishan-US to Meishan-China, as set forth by NP, is problematic due to GD. As an imported breed becomes established there will be an increasing number of breeders who may have different selection goals and private treaty contracts will govern the exchange of stock between them. Therefore, considering biological phenomena and social dynamics simultaneously draws into question whether a rigorous access and benefit sharing protocol as envisioned in the NP will be operational.

This study aimed at characterising the genetic diversity of two Fipa cattle populations (Sumbawanga and Nkasi) of South-Western Tanzania, and establishing their genetic relationships with the other indigenous cattle strains (Tarime, Iringa red and Ankole) and Friesian cattle found in the area. The genetic diversity was analysed using 30 microsatellite markers. All the markers used were highly polymorphic. The Nkasi Fipa cattle exhibited the highest mean number of alleles (7.31) and mean genetic diversity (0.732) per locus, followed by Sumbawanga Fipa cattle with 7.10 mean number of alleles and 0.725 mean genetic diversity per locus, with the latter population having a very low mean inbreeding coefficient (F IS = 0.027). Three percent of the genetic diversity was due to differences among indigenous strains while the rest was due to differences among individuals within the strains. Small genetic distances (D A) were observed between Sumbawanga Fipa and Nkasi Fipa (0.032), Tarime (0.073), Iringa red (0.076) and Ankole cattle (0.086). As expected, the largest genetic distances were observed between the Friesian and all indigenous strains since this breed has a quite distinct genetic origin. In the assignment test, the proportion of animals from each group correctly assigned to their source population ranged from 55.3 percent (for Nkasi Fipa) to 100 percent (for Friesian). Despite the low genetic differentiation and genetic indistinctiveness of the Sumbawanga Fipa population from the other indigenous strains, its high genetic diversity, very low inbreeding coefficient and a threat emanating from population admixture with other indigenous strains underscore the importance of establishing appropriate conservation and management strategies for it.

As part of the requirements of the Convention on Biological Diversity, Canada has been investigating the genetic diversity of its native equine and pony populations. Along with examining four indigenous Canadian equine populations (Canadian horse, Lac La Croix pony, Newfoundland pony and Sable Island population), another 10 Mountain and Moorland, three Nordic, four horse and two feral equine populations (thought to have influenced some pony breeds) were also investigated. In total, 821 individuals were genotyped at 38 microsatellite loci. Results of the analysis of molecular variance indicated that 13.3% of genetic diversity was explained by breed differences, whereas 84.6% and 2.1% of diversity came from within and among individuals, respectively. The average effective number of alleles and allelic richness was the lowest in the Eriskay (2.51 and 3.98) and Lac La Croix (2.83 and 4.01) populations, whereas it was highest in the New Forest (4.31 and 6.01) and Welsh (4.33 and 5.87) breeds, followed closely by the Newfoundland-CDN (4.23 and 5.86) population. Expected heterozygosities varied from 0.61 in the Lac La Croix to 0.74 in the Welsh and in Newfoundland. Observed heterozygosities ranged from 0.57 in the Exmoor and 0.58 in the Sable Island herd to 0.77 in the Kerry Bog and 0.76 in the New Forest breeds. Structure and admixture analyses revealed that the most likely number of clusters was 21, although some substructure was also observed when K = 16, compared with the 24 predefined populations. Information gathered from this study should be combined with other available phenotypic and pedigree data to develop, or amend, a suitable conservation strategy for all populations examined.

Karyotyping and hypervariable genetic markers indicate extensive leucochimaerism between pairs of dizygotic twins in cattle, a result of placental vascular anastomosis. The extent of this chimaerism includes both kind and number of cells exchanged. All heterosexual twin pairs harboured two types of leucocytes, having either XX or XY chromosome pairs, and 30 of 31 pairs of twins shared identical DNA fingerprints. Although chromosome results from skin fibroblasts indicate that some chimaerism occurs in the skin, the low level allows for differentiation of genotypes between twins. The results warrant against the common practice of using blood samples for DNA typing if twinning is not properly documented.

It is believed that short interspersed elements (SINEs) are irreversibly inserted into genomes. We use this concept to try to deduce the evolution of whales using sequence and hybridization studies. The observation that microsatellites are associated with SINEs lead us to screen sequences surrounding cetacean microsatellites for artiodactyl-derived SINEs. Two sequences that were thought to be cetacean SINEs and the bovine SINE were aligned for comparison to sequences flanking microsatellites from ungulates. The bovine SINE was observed only in ruminants while CetSINE1 and 2 were found in mammals. Hybridization studies using these three SINEs revealed that CetSINE1 was found in all ungulates and cetaceans with the strongest hybridization signal observed in the hippopotamus and beluga; CetSINE2 hybridized to all ungulate suborders, while the bovine SINE was only observed in Ruminantia. It is proposed that these putative SINEs are not 'generic' SINEs but mammalian-wide interspersed repeats (MIRs). Caution is urged: what initially appears to be a SINE may instead be a MIR and have reduced evolutionary resolving power.

The pluripotency of embryonic germ cells in the mouse suggests that mitotic bovine fetal germ cells might also be a source of pluripotent cells. To investigate the pluripotency of bovine oogonia, the development in vitro of bovine embryos reconstructed by fusing oogonia with enucleated oocytes was compared with that of embryos made similarly with either blastomeres or granulosa cells. The donor cells (fresh oogonia, cryopreserved oogonia, 16- to 32-cell-stage blastomeres, or granulosa cells) were fused to the enucleated oocytes electrically The proportions of reconstructed embryos that had cleaved at 40 h after fusion using these types of donor cells were not significantly different (37%, 33%, 56%, and 31%, respectively; p > 0.05). However, the proportions of cleaved reconstructed embryos that developed to the blastocyst stage were 9%, 13%, 36%, and 3%, respectively, significantly higher (p less than or equal to 0.05) with blastomeres than with the other three types of donor cells. After transfer of 3 morulae and 4 blastocysts made with oogonia into three recipient heifers, embryonic and extra-embryonic tissues developed in one animal. On recovery after 43 days gestation, this conceptus was shown to be genetically identical, at 11 microsatellite loci, to the fetus that had provided the oogonia. Cytological analysis of the embryos made with oogonia at 40-44 h after fusion and at the morula and blastocyst stages revealed that aberrant cytokinesis and nucleokinesis had given rise to multinucleated, anucleate, and polyploid cells in the reconstructed embryos. It is concluded that limited pluripotency of bovine oogonia has been demonstrated, warranting further study in this area.

DNA microsatellites originally detected in sheep and cattle are also detectable in North American elk (Wapiti) using polymerase chain reactions. We have developed a parentage test in elk using eleven microsatellite markers that are highly polymorphic and informative.