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Genetic diversity in natural populations of Japanese Potamoid crabs

日本马铃薯蟹自然种群的遗传多样性

基本信息

批准号：
09839027
负责人：
AOTSUKA Tadashi
金额：
$ 2.11万
依托单位：
TOKYO METOROPOLITAN UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

Japanese Potamoid consists of 15 species divided into 3 genea (Geotholphusa, Candidiopotamon and Ryukyum). Among the species, only G. dehaani inhabits widely through Honsyu to Kagoshima and the distributions of the other species are restricted in the Ryukyu Islands. We studied genetic variation in natural populations for each species or genetic differentiation among species mainly by using mtDNA sequence determination.In natural populations of G. dehaani, extensive genetic divergence was observed. The genetically differentiated populations are usually distributed parapatrically and very narrow hybrid zones are formed at where they come into contact with each other. Detailed genetic structure at the hybrid zones were investigated in relation to the development of reproductive isolation between genetically differentiated parental populations. From the results we discussed the factors that are responsible to maintain the very narrow hybrid zones.Based on nucleotide sequence variation in ND2 gene of mtDNA (1,008-1,011 bp) phylogenetic relationships were inferred for 15 species of Japanese Potamoid. Our results supported some previous taxonomic aspects from morphological studies. The genus Candidiopotamon, however, was not shown as a robust assemblage in the molecular tree. Moreover, phylogenetic relationships among species of Geothelphusa were not consistent with that of deduced from morphological or ecological studies. Phylogenetic relationships revealed in the present study suggests that the major evolutionary lineages of Japanese Potamoid have occurred at 200-250 mya when the Ryukyu region was thought to be separated into some land blocks.

日本 Potamoid 由 15 个物种组成，分为 3 个属（Geotholphusa、Candidiopotamon 和 Ryukyum）。其中，仅G. dehaani广泛栖息于本州至鹿儿岛，其他物种的分布仅限于琉球群岛。我们主要通过mtDNA序列测定来研究每个物种自然群体中的遗传变异或物种之间的遗传分化。在G. dehaani自然群体中，观察到广泛的遗传分化。遗传分化的种群通常是近亲分布，并且在它们彼此接触的地方形成非常狭窄的杂交区。研究了杂交区的详细遗传结构与遗传分化的亲本群体之间生殖隔离的发展的关系。根据结果，我们讨论了维持非常狭窄的杂交区的因素。根据mtDNA（1,008-1,011 bp）ND2基因的核苷酸序列变异，推断了15个日本Potamoid物种的系统发育关系。我们的结果支持了形态学研究之前的一些分类学方面。然而，念珠菌属在分子树中并未显示为强大的组合。此外，Geothhelphusa 物种之间的系统发育关系与形态学或生态学研究推论的并不一致。本研究揭示的系统发育关系表明，日本 Potamoid 的主要进化谱系发生在 200-250 mya，当时琉球地区被认为被分成了一些陆地块。