权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Possibility of sperm competition in spermathecae of ants

蚂蚁受精囊中精子竞争的可能性

基本信息

批准号：
07640829
负责人：
HIGASHI Seigo
金额：
$ 1.41万
依托单位：
HOKKAIDO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1997
项目状态：
已结题

项目摘要

CAP-PCR DNA Fingerprinting method was used for estimating the insemination frequency of ant queens, because this method had the following advantages for analyzing kin relatedness : 1) The required amount of DNA was as small as 50 ng, which is available even from very tiny insects. 2) The variation of band pattern was large and only a few individuals or colonies were required for the analysis of kin relatedness. 3) Band patterns from the same sample were almost always identical ; thus, the reproducibility was very high. Accordingly, queens of most ant species were monandrous and only a few species showed polyandry. That is, sperm cells of different males rarely coexist in a spermatheca of a queen. Probably because of this, I could not find any evidence of sperm competition in the present study.Nonetheless, some sociobiologically important results were obtained in this study : 1) In the tribe Attini which is distributed in South and Central America, such socially higher genera as Atta, Acromymex and Sericomyrmex were polyandrous, while lower genera such as Cyphomyrmex and Myrmicocrypta showed monandry. This suggests that the polyandry contributes to the evolution of effective polyethism and huge societies of social insects. 2) As theoretically predicted, the sex ratio was distorted to females in the monandrous species, though the ratio of the females decreased in the polyandrous species. In Atta the sex ratio was obviously distorted to males for unknown reasons. 3) Fungi were the staple food of larvae and queens but not of abult workers, unlike the prediction of four hypotheses which have been proposed to account for the evolution of mycophagy in Attini. This means that another hypothesis have to be considered under the condition that the mycophagy evolved for lavae.

CAP-PCR DNA指纹法用于蚁后授精频率的测定，具有以下优点：1）DNA需要量小，仅需50 ng，即使是很小的昆虫也能获得。2)带型变异较大，仅需少量个体或群体即可进行亲缘关系分析。3)来自同一样品的条带模式几乎总是相同的;因此，重现性非常高。因此，大多数蚁种的蚁后是单雄的，只有少数种类表现出一妻多夫。也就是说，不同雄性的精子细胞很少共存于蜂王的受精囊中。本研究获得了一些重要的社会生物学结果：1）在分布于中南美洲的Attini族中，社会地位较高的属如Atta、Acromymex和Sericomyrmex为多雄生殖，而社会地位较低的属如Cyphomyrmex和Myrmicocrypta为单雄生殖。这表明，一妻多夫制有助于有效的多种族制和巨大的社会昆虫社会的进化。2)正如理论预测的那样，在单雄生殖的物种中，雌性的比例被扭曲，尽管在多雄生殖的物种中雌性的比例下降。在阿塔，由于未知的原因，性别比例明显扭曲为男性。3)真菌是幼虫和蚁后的主食，但不是abult工人，不像预测的四个假设已提出的解释在Attini的mycophagy的演变。这意味着另一种假设，必须考虑的条件下，菌噬进化的lavae。