2024-03-29T13:07:40Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/8902022-11-17T02:08:08Zhdl_2115_20046hdl_2115_138Application of artificial insemination technique to eupyrene and/or apyrene sperm in Bombyx mori1000030241368Sahara, Ken佐原, 健Takemura, Yokoopen accessCopyright (c) 2003 John Wiley & Sons, Inc.silkwormlepidopteraspermatozoabundlesfemalepyralidaemoth633The silkworm, Bombyx mori, has a dimorphic sperm system. The eupyrene sperm is the sperm to fertilize eggs and the apyrene sperm plays a crucial role for assisting fertilization. Heat-treated (331C for 96h) Daizo (DH) males, one of the strains in the silkworm, produce only eupyrene sperm, while in triploid males only apyrene sperm are functional. Though both types of males are found to be sterile, double copulation of the two males with a single female greatly increases fertility. Here we examined the fertilizing ability of eupyrene and apyrene sperm by means of an artificial insemination technique previously established in B. mori. Neither the eupyrene sperm collected from DH males, nor the apyrene sperm from triploid males have the ability to fertilize eggs. Artificial insemination with the mixture of eupyrene and apyrene sperm leveled up the frequency of fertilized eggs to more than 80%. When cryopreserved DH sperm (eupyrene sperm) were subjected to the same experiment, more than 95% fertilized eggs were obtained. These results confirmed that apyrene sperm play an important and indispensable role in fertilization in B. mori. Separate collection of functional eupyrene sperm and functional apyrene sperm and success of fertilization by means of the artificial insemination technique are applicable for further studies to elucidate the function of apyrene sperm. J. Exp. Zool. 297A:196–200, 2003.Wiley-Liss, Inc.2003-05engjournal articleAMhttp://hdl.handle.net/2115/890https://doi.org/10.1002/jez.a.102500022-104XJournal of Experimental Zoology Part A: Comparative Experimental Biology2972196200https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/890/1/JEZ-A%20297A2%20.pdfapplication/pdf147.48 KB2003-05