2014 Fiscal Year Final Research Report
Sperm Competition in the Swallowtail Butterflies: final conflict of apyrene sperm
Project/Area Number |
24570019
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Multi-year Fund |
Section | 一般 |
Research Field |
Ecology/Environment
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Research Institution | University of Tsukuba |
Principal Investigator |
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Project Period (FY) |
2012-04-01 – 2015-03-31
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Keywords | 有核精子 / 無核精子 / 交尾嚢 / 受精嚢 / 精子移動 / 精包 / 精子活性 / 単婚制 |
Outline of Final Research Achievements |
Lepidopteran males including swallowtail butterflies transfer two types of sperm, nucleated eupyrene and non-nucleated apyrene sperm, within a single spermatophore. Both types of sperm migrate to the spermatheca. The cheap filler hypothesis has been proposed on the role of apyrene sperm in the polyandrous species, where motile apyrene sperm in the spermatheca reduce female receptivity of re-mating. Males of monandrous species also produce apyrene sperm, migrating to the spermatheca. Sperm dynamics and the motility of apyrene sperm in the spermatheca after copulation were examined in polyandrous and monandrous species. In the polyandrous species, apyrene sperm disappeared from the spermatheca in a couple of days after the copulation. In the monandrous species, although apyrene sperm remain in the spermatheca long time after copulation, they lost the motility soon after the migration to the spermatheca. Then, alternative hypotheses of the role of apyrene sperm was discussed.
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Free Research Field |
生態学
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