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 指纹图谱法被用来估算蚁后的授精频率，因为该方法对于分析亲缘关系具有以下优点： 1) 所需的 DNA 量低至 50 ng，即使从非常小的个体中也可以获得昆虫。 2）带型变异较大，仅需要少数个体或群体即可进行亲缘关系分析。 3) 同一样品的条带图案几乎总是相同的；因此，再现性非常高。因此，大多数蚂蚁种类的蚁后都是单性的，只有少数种类表现出一妻多夫制。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。可能正因为如此，我在本研究中找不到任何精子竞争的证据。尽管如此，这项研究还是获得了一些具有社会生物学意义的重要结果：1）在分布于南美洲和中美洲的Attini部落中，这种社会地位较高的属Atta、Acromymex 和 Sericomyrmex 是一妻多夫，而低等属如 Cyphomyrmex 和 Myrmicocrypta 则是一妻多夫。这表明一妻多夫有助于有效的多民族主义和庞大的社会性昆虫社会的进化。 2）正如理论上所预测的那样，尽管一妻多夫物种中雌性的比例有所下降，但单雄物种中的性别比例向雌性倾斜。在阿塔，性别比例明显扭曲为男性，原因不明。 3）真菌是幼虫和蚁后的主食，但不是工蜂的主食，这与阿蒂尼中为解释菌食进化而提出的四个假设的预测不同。这意味着在噬菌体是为熔岩进化的情况下，必须考虑另一个假设。