Genetical and chromosomal differentiation in the Nelima genufusca group (Arachnida, Opiliones) and dynamics of the hybrid zones.

Nelima genufusca 群体（蜘蛛纲、Opiliones）的遗传和染色体分化以及杂交区的动态。

基本信息

批准号：
06640901
负责人：
TSURUSAKI Nobuo
金额：
$ 1.34万
依托单位：
Tottori University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06640901/
关键词：
Chromosomes Hybrid zone Speciation MtDNA Nelima nigricoxa Opiliones Arachnida

项目摘要

To infer the differentiation processes of karyotypes in three species of the genufusca-group, Nelima nigricoxa, N.sp. (tentatively called Ezonami-zatomushi in Japanese), and N.genufusca, chromosomal survey has been made for more than 100 populations of the group. As a reference, some populations of two additional species (Nelima satoi and N.aokii) belonging to the satoi-group have also been karyotyped. As a result, the numbers of chromosomes were found to be 16 and 22 for two species of the satoi group and Nelima sp. (Ezonami), respectively. On the other hand, Nelima nigricoxa and N.genufusca showed a wide range of variation in the chromosome number : 2n=16-22 and 2n=18-22, respectively. Both the outgroup comparison and geographic patterns of distribution of the karyotypes suggest that the number successively decreased within the ranges of both species.A hybrid zone found in western part of Tottori Prefecture, Honshu was analyzed in detail. Frequency of the individuals with 2n=19 in the hybridized population (2n=20/19/18a : Kawadoko on the northern slope of Mt.Daisen) was significantly lower than the expected value from Hardy-Weinberg's theorem (p<0.02). This indicates decrease of fitness in hybrids between 2n=20 and 18a and in turn it may partly account for the narrowness of the hybrid zone. However, no evidence of disorder in the spermatogenesis was obtained for the heterozygotes with 2n=19.To estimate the degree of differentiation at the genic level among races with three different karyotypes (16,18a, and 20), the sequences of bases of the DNA fragments of the Co1 (cytochrome oxidase 1) were determined for six populations of Nelima nigricoxa. In six sites out of 310 bp, substitutions of the bases were found among populations with three different karyotypes. More detailed comparison using restriction endonucreases is now undertaken.

为了推断Genufusca-Group的三种核型的分化过程，N.Sp. Nelima Nigricoxa。（暂定地称为日语中的ezonami-zatomushi）和N.Genufusca，对该组的100多个人群进行了染色体调查。作为参考，属于Satoi-Group的另外两个种群（Nelima Satoi和N.Aokii）也已被核分型。结果，发现Satoi组和Nelima sp的两种染色体的数量为16和22。（Ezonami）分别。另一方面，Nelima Nigricoxa和N.Genufusca在染色体数中显示出广泛的变化：2n = 16-22和2n = 18-22。核型的外群比较和地理分布模式都表明，在这两个物种的范围内，数量连续下降。杂交人群中2N = 19的个体的频率（2n = 20/19/18a：daisen北坡上的kawadoko）明显低于Hardy-Weinberg定理的预期值（p <0.02）。这表明杂种在2n = 20至18a之间的适应性降低，进而可能部分解释了杂交区的狭窄。然而，没有获得2n = 19的杂合子的精子发生中的疾病，以估计具有三种不同的核型（16,18a和20）的种族中基因水平的分化程度，这是该种族的分化度，确定了六个Nelima Nigricoxa种群的Co1（细胞色素氧化酶1）的DNA片段。在310 bp的六个地点中，在三种不同的核型中发现了碱基的取代。现在正在进行使用限制性核能进行更详细的比较。

项目成果

期刊论文数量（32）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Tsurusaki,N.: "Sungsotia uenoi gen.n.,sp.n.(Arachnida,Opiliones,Phalangodidae),a cavernicolous harvestman from nor thern Vie Tnam." Spec.Bull.Jpn.Soc.Coleopterol.,Tokyo. No.4(印刷中). (1995)

Tsurusaki, N.：“Sungsotia uenoi gen.n.，sp.n.（蛛形纲，Opiliones，Phalangodidae），一种来自北部 Vie Tnam 的海绵状收割者。”Spec.Bull.Jpn.Soc.Coleopterol.，东京第 1 号。 4（正在出版）（1995）。