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The Bonin flying fox (Pteropus pselaphon) is endemic to the Ogasawara Islands, a collection of small oceanic islands in the Pacific Ocean. It inhabits only five islands: Chichi-jima, Haha-jima, Kita-iwo, Iwo, and Minami-iwo (arranged from north to south). Hahajima and Kita-iwo, the most widely spaced islands, are separated by a distance of about 160 km. The islands have different histories in the modern era with respect to human activity. At present, P. pselaphon population sizes exceed 100 on Chichi-jima and Minamiiwo, but the species is rare on the other three islands. Loss of genetic diversity is of concern because of the small population sizes. We obtained samples from three of the five islands — Chichi-jima, Kita-iwo, and Minami-iwo — and investigated species genetic diversity and genetic structure based on mitochondrial DNA (mtDNA) control region sequences and microsatellite markers. Different mtDNA haplotypes were found in each island population. Based on the mtDNA sequence data, P. pselaphon displayed a cryptic genealogy, as haplotypes on each island did not cluster together. The microsatellite marker data, however, revealed a clear genetic structure among the island populations, suggesting the absence of recent inter-island gene flow. Based on these results, we propose that the individual island populations are not evolutionarily significant units, but should be conserved collectively as a single management unit.
We examined sequence variation in mitochondrial and nuclear genes of seven species of the genus Martes (Mustelidae, Carnivora): Martes americana (American marten), Martes flavigula (yellow-throated marten), Martes foina (beech marten), Martes martes (pine marten), Martes melampus (Japanese marten), Martes pennanti (fisher) and Martes zibellina (sable), focusing on the phylogenetic history of the Hokkaido subspecies of the sable, Martes zibellina brachyura. Nucleotide sequence analysis of the mitochondrial cytochrome b gene confirmed the view that the Hokkaido sable population has lower genetic diversity. In contrast, network analysis of a nuclear gene related to coat colour, melanocortin-1 receptor (Mc1r), revealed two different haplogroups for this population: one shared with that of Russian sables and the other specific to this population but with a close relationship with the American and Japanese martens, implying that these endemic haplotypes are composed of uncharacterised ancestral lineages of a past population. We also examined the sequence variation in a neighbouring nuclear gene, transcription factor 25 (Tcf25), located about 5 kb upstream from the Mc1r gene, and found similar trends. The sable genome leaves the impression that Hokkaido hosted ancient marten lineages, with subsequent recent migrations from the continent. The validity of a candidate Mc1r mutation for the entirely yellow coat observed on Hokkaido sables was also discussed.
Molecular phylogeny of crocidurine shrews (Insectivora, Soricidae) in northeastern Asia was investigated to confirm the taxonomic status of unidentified specimens of Crocidura from Cheju Island, South Korea. Phylogenetic trees were constructed by neighbor-joining (NJ) and maximum likelihood (ML) methods, based on mitochondrial cytochrome b gene sequences (402 base pairs) of 37 individuals of seven crocidurine species and three unidentified specimens from 31 localities mainly in northeastern Asia. Phylogenetic position of the three unidentified specimens from Cheju Island were compared with those of Suncus murinus, C. attenuata, C. dsinezumi, C. lasiura, C. sibirica, C. suaveolens, and C. watasei. Both in NJ and ML trees, the three unidentified specimens were included in the cluster of C. dsinezumi and were obviously different from C. suaveolens on Cheju Island. Thus, the present investigation demonstrated that both C. suaveolens and C. dsinezumi exist on Cheju Island.
A heterologous prime-boost vaccination regime with DNA and recombinant vaccinia virus (rvv) vectors expressing relevant antigens has been shown to induce effective immune responses against several infectious pathogens. In this study, we describe the effectiveness of the prime-boost strategy by immunizing dogs with a recombinant plasmid followed by vaccinia virus, both of which expressed the glutamic acid-rich protein (BgGARP) of Babesia gibsoni. The dogs immunized with the prime-boost regime developed a significantly high level of specific antibodies against BgGARP when compared with the control groups. The antibody level was strongly increased after a booster immunization with a recombinant vaccinia virus. Two weeks after the booster immunization with a recombinant vaccinia virus expressing BgGARP, the dogs were challenged with B. gibsoni parasite. The dogs immunized with the prime-boost regime showed partial protection, manifested as a significantly low level of parasitemia. These results indicated that this type of DNA/rvv prime-boost immunization approach may have use against B. gibsoni infection in dogs.
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