@misc{oai:ir.soken.ac.jp:00001004,
 author = {小見山, 智義 and コミヤマ, トモヨシ and KOMIYAMA, Tomoyoshi},
 month = {2016-02-17},
 note = {This study gives clarity to the origin and evolution of domesticated chickens in Asia in view of molecular evolution. For domesticated chickens, evolution is tightly related to many aspects of human nature and culture. Because of the interest in the evolutionary process involved with such human factors, domesticated chickens have been chosen for study because of their evolutionary origin and process that has been deeply influenced by human factors.<br />　　　Man has domesticated and bred chickens for various purposes for a long time. For example, a fighting cocks, Shamo, and long-crowing chickens, Naganakidori, are typical examples that must have been bred for the purposes of entertainment and appreciation that are part of human culture. For this reason, these two varieties of domesticated chickens are excellent materials for the study of how human culture has influenced the domestication and breeding process of animals.<br />　　　A variey of cultural aspects of raising and keeping Shamo and Naganakidori have been observed not only in Japan but also in other Asian countries such as Thailand and China. Therefore, the understanding of the geographical origin and domestication process of Shamo and Naganakidori is one of the key issues for elucidating the relationships between human culture and its reflective breeding efforts. However, it is of prime importance to study their evolutionary origin and phylogenetic relationships using DNA sequence data, because their molecular phylogenetic relationships will be so objective and reliable as to form the bases of the discussion about domestication and breeding of chickens.<br />　　　Chapter 1 explained the background of the studies of domesticated chickens from the viewpoint of evolutionary biology and cultural intervention. It also described the purpose and biological significance of the present study.<br />　　　Chapter 2 focused upon the evolutionary origin of Japanese fighting cocks. A total of 42 blood samples were collected and measured three morphological traits (height, weight, and  shank length) of fighting cocks, Shamo, in nine places in Japan. Moreover, in collaboration  with colleagues in Myanmar and Southeast China, blood samples of domesticated chickens in  their respective regions were also examined. Extracting the mitochondrial DNAs from the blood samples and sequencing their D-loop regions, phylogenetic trees of the domesticated chickens were constructed. The phylogenetic analysis has shown that the Japanese Shamo was separated into two groups: One group contained exclusively individuals from the island of Okinawa, and the other was composed of the individuals from Kyushu and Honshu islands of Japan.<br />　　　The results of the phylogenetic analysis are consistent with that of the morphological  analysis of the three traits. In particular, the Okinawa Shamo showed consistently larger values  of height, weight, and shank length than the other Shamo groups studied. This observation  supports that the Japanese Shamo has come frorn two separate origins. It is also known that  different names are used for calling Shamo in Japan. In Okinawa, Shamo is pronounced as "taut∫i:" which is quite similar to its Chinese pronunciation. In the other parts of Japan, it is pronounced as "shamo" which is very similar to the pronunciation of the old name of "Thailand." This cultural aspect also supports the separate origins of Japanese Shamo.<br />　　　In Chapter 3, to elucidate the evolutionary origin and the domestication process of Naganakidori, nine blood samples of this variety were collected from five places in Japan. In Japan, three varieties of Naganakidori; Koeyoshi, Totenko, Tomaru, have been bred to develop an exceptionally long crow of over 15 seconds. the mitochondrial DNA was then extracted and its D-loop region sequenced. When a molecular phylogenetic tree was constructed, it was found that all three varieties were monophyletically related. This finding is surprisingly interesting, because the three varieties are remarkably different to each other in morphological characters. Moreover, Naganakidori's group is located between the group of Okinawa Shamo and the other Shamo group. It strongly suggests that Naganakidori originated from Shamo.<br />　　　Chapters 4, on the basis of the results of Chapters 2 and 3, 34 samples from 12 varieties of the ornamental chickens were examined to understand their evolutionary origin. Then, it was found that all the ornamental chickens examined have been derived from Shamo. It strongly suggested that all Japanese domesticated chickens including the ornamental chickens and Naganakidori might have been originated from Shamo, particularly the ancestor of Okinawa Shamo. The conclusion is that the intensive pressure of artificial selection was imposed on the Shamo population that had been already established for the tradition of cockfighting in order to create novel variation of ornamental chickens, resulting in profound differentiation of Japanese varieties of domesticated chickens.<br />　　　Chapter 5 considered the background that the original Shamo has produced Japanese domesticated chickens, from both historical and biological approaches. The conclusion is that the ancestral Shamo was brought first into Okinawa and then distributed over Japan through driving forces such as appreciation, entertainment, and competition that are certainly part of human nature and culture. <br />　　　Finally, it should be emphasized that this study would eventually provide basic and useful information related not only to the evolutionary process but also the important issues such as the animal protection, nature conservation, and global environments., 総研大乙第128号},
 title = {The mitochondrial DNA sequence analysis of domesticated chickens and its implication to the evolutionary origin of fighting cocks},
 year = {}
}