著者
Jun YAMASHITA Hironori OKI Telhisa HASEGAWA Takeshi HONDA Tetsuro NOMURA
出版者
Japanese Society of Equine Science
雑誌
Journal of Equine Science (ISSN:13403516)
巻号頁・発行日
vol.21, no.2, pp.11-16, 2010 (Released:2010-07-16)
参考文献数
12
被引用文献数
3 2

To investigate the breeding structure in the Japanese Thoroughbred population, we applied a demographic analysis to the populations of foals produced from 1978 to 2005. The migration rate estimated from the proportion of foals produced by imported breeding horses was around 40% over the investigated period. After early 1990s, the migration rate through stallions imported from USA sharply increased. The average generation interval was within range of 10.5-11.5 years. The longer generation interval of Thoroughbred was considered to be a reflection of the fact that Thoroughbred horses begin breeding only after completing their performance in races. After the peak of 729 in 1993, the number of sires of foals progressively declined to 358 in 2005. Although the coefficient of variation of the progeny number of sires was within range of 1.0-1.2 until early 1990s, it gradually increased and reached the value of 1.6-1.7 in recent years. The effective number of sires consistently decreased after the peak of 302.6 in 1992, and reached 120-130 in recent years, which is 25-30% of the actual number of sires. In parallel, the demographic estimate of the effective population size declined after early 1990s. The main cause of the observed change in the breeding structure was inferred to be the intensive use of a limited number of stallions for breeding.
著者
高橋 純一 野村 哲郎 Jun-ichi TAKAHASHI Tetsuro NOMURA 京都産業大学総合生命科学部 京都産業大学総合生命科学部
出版者
京都産業大学先端科学技術研究所
雑誌
京都産業大学先端科学技術研究所所報 = The bulletin of the Research Institute of Advanced Technology Kyoto Sangyo University (ISSN:13473980)
巻号頁・発行日
vol.14, pp.31-40, 2015-07

ミツバチ科マルハナバチに属するエゾオオマルハナバチBombus hypocrita sapporoensisは、特定外来種であるセイヨウオオマルハナバチの代替花粉交配用昆虫として注目されている。今回我われは、本種の農業利用を進めるための遺伝育種学的解析に必要なマイクロサテライトDNAマーカーの適用性を検討した。120種類のマーカーのうち、57種類が多型解析に利用できることがわかった。さらに8種類のプライマーは、マルチプレックスPCRによる同時解析が可能であることを明らかにした。これらのツールキットを利用して女王蜂の受精嚢内から単離した精子DNAの解析を行ったところ、交配雄蜂の遺伝子型を特定できることがわかった。 The Bumblebee is a eusocial Hymenoptera with an annual life cycle and is often utilized as an agricultural pollinator. We developed an polymorphic microsatellite DNA toolkit for the Japanese bumblebee Bombus hypocrita sapporoensis using multiplex PCR. At 57 of these 120 loci, high allelic variation was observed in 20 individual males. In addition to a method of spermathecae PCR, we developed 8 polymorphic microsatellite DNA toolkit for the B. h. sapporoensis. These results suggest that high-throughput genotyping method can be used to gain more information regarding breeding systems and for more deeply understanding social evolution in the B. h. sapporoensis.