title: Establishment of hybrid-derived offspring populations in the Ohomopterus ground beetles through unidirectional hybridization.
abstract: An approach to deduce the mechanism of stabilization of the hybrid-derived populations in the Ohomopterus ground beetles has been made by comparative studies on the phylogenetic trees of the mitochondrial and nuclear DNA. A phylogenetic tree based on the internal transcribed spacer (ITS) of nuclear ribosomal gene roughly reflects the relations of morphological species group, while mitochondrial NADH dehydrogenase subunit 5 (ND5) gene shows a considerable different topology on the tree; there exist several geographically-linked lineages, most of which consist of more than one species. These results suggest that the replacement of mitochondria has occurred widely in the Ohomopterus species. In most cases, hybridization is unidirectional, i.e., the species A (♂) hybridized with another species B (♀) and not vice versa, with accompanied replacement of mitochondria of A by those of B. The results also suggest that partial or complete occupation of the distribution territory by a hybrid-derived morphological species. The morphological appearance of the resultant hybrid-derivatives are recognized as that of the original species A. Emergence of a morphological new species from a hybrid-derived population has been exemplified.
authors: JT Biohistory Research Hall, 1-1 Murasaki-cho, Takatsuki, Osaka 569-1125, Japan .
authors: Zhi-Hui
authors: ZH
authors: Su
authors: Department of Laboratory Animal Science, School of Veterinary Medicine, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan .
authors: Munehiro
authors: M
authors: Okamoto
authors: A321, 4-1-15, Shibatsuji-cho, Nara 630-8114, Japan .
authors: Osamu
authors: O
authors: Tominaga
authors: Hisaiiba-cho 66, D-304, Tsu-shi, Mie 514-1108, Japan .
authors: Katsumi
authors: K
authors: Akita
authors: Hosen-Gakuen High School, Chuo, Nakano-ku, Tokyo 164-8628, Japan .
authors: Noboru
authors: N
authors: Kashiwai
authors: Shinohara-chô 1249-8, Kôhoku-ku, Yokohama 222-0026, Japan .
authors: Yûki
authors: Y
authors: Imura
authors: Sato-machi, Gantotsuka 3-40, Anjo-shi, Aichi 446-0008, Japan .
authors: Tooru
authors: T
authors: Ojika
authors: Iida-Nishi, 2-2-8, C-502, Yamagata-shi 990-2331, Japan .
authors: Yoshiyuki
authors: Y
authors: Nagahata
authors: JT Biohistory Research Hall, 1-1 Murasaki-cho, Takatsuki, Osaka 569-1125, Japan .
authors: Syozo
authors: S
authors: Osawa
keywords: ITS I; ND5 gene; Ohomopterus ground beetles; mitochondrial flow; phylogenetic trees; unidirectional hybridization