2009 年 12 巻 1 号 p. 27-31
The wild boar (Sus scrofa leucomystax) population in Chiba prefecture, Japan, went extinct in the 1970's, subsequently recovering since 1986. To investigate genetic differences between this extinct population and contemporary wild boar populations in Chiba, we analyzed mitochondrial DNA (mtDNA) from wild boar specimens from the 1940s and 50s and contemporary animals. We successfully sequenced 572 base pair (bp) fragments of the mtDNA control region from three of four bones from extinct boars, and from 18 samples from contemporary wild boars. In the remaining of the four bones from the extinct population, only 385 bp of the 572 bp fragment were successfully sequenced. All specimens from the 1940s and 50s had haplotype J8, whereas contemporary boars had J3 and J10. Our findings indicated that the haplotype composition of the extinct boars was different from that of the modern population. Haplotype composition differences are not likely to be caused by migrations from neighboring prefectures to Chiba, because the current Chiba population is isolated from other populations. The contemporary population of wild boars in Chiba may have originated from escapes and/or introductions of feral boars or Inobuta from breeding farms.