Studies on the species evolution in Paramecium caudatum

尾草履虫物种进化研究

基本信息

批准号：
10041155
负责人：
TAKAHASHI Mihoko
金额：
$ 4.35万
依托单位：
Institute of Biological Sciences, University of Tsukuba
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

项目摘要

To study the species evolution in Paramecium caudatum, many natural strains at different geographic places are necessary, and establishment by recovery of the lost syngen (genetical species) is essential. Therefore, I carried out collection of natural strains in USA, Canada and Uruguay Republic.1. The collections were carried out at 197 points around the Five lakes and the eastern part of USA, and at 78 points in Uruguay Republic. P. caudatum was obtained from 34 sampling points, and 222 isolation lines were established.2. Three groups consisting in complementary mating types, that is "syngen", were discovered. These three syngens are independent from known syngens. They are tentatively called as syngen a, syngen b and syngen d. New strains belonging to syngen 1, syngen 3, syngen 5 and syngen 12 were also obtained.3. Surprisingly, a problem in identification of species revealed from the analyses of some strains, for example UC131 or UC151. They look like P. caudatum very much in size of cells and external morphology, but their RAPD patterns are quite different from many strains of P. caudatum. They have 2-5 vesicular type micronuclei, two contractile vacuoles and living in fresh water. These characteristics are not identical to the known biological species. Further studies are necessary whether they are really new biological species or not.4. Some strains show inter-syngen mating reactions. This evidence emphasizes an importance of establishment of the syngen standard strains.

为了研究尾tar虫的物种进化，有必要在不同地理位置的许多天然菌株，而通过恢复丢失的合成基因（遗传物种）建立是必不可少的。因此，我在美国，加拿大和乌拉圭共和国收集了天然菌株1。这些收藏是在五个湖泊和美国东部的197点上进行的，在乌拉圭共和国的78分。从34个采样点获得了尾状曲霉，并建立了222条隔离线。2。发现了由互补交配类型组成的三个组，即“合成”。这三个合伙们独立于已知的综合基因。它们被暂时称为Syngen A，Syngen B和Syngen d。还获得了属于Syngen 1，Syngen 3，Syngen 5和Syngen 12的新菌株3。令人惊讶的是，从某些菌株的分析（例如UC131或UC151）中揭示的物种的鉴定问题。它们看起来像尾状的尾状细胞大小和外部形态的大小，但它们的RAPD模式与许多尾p. caudatum菌株截然不同。他们有2-5个囊泡类型的微核，两个收缩液泡，生活在淡水中。这些特征与已知的生物物种并不相同。无论是否真正是新的生物物种，都需要进一步的研究。4。一些菌株表现出伴侣间交配反应。该证据强调建立Syngen标准菌株的重要性。