Drosophila males heterozygous for the segregation distorter chromosome show a reduction in fecundity which is correlated with the degree of distortion of their segregation ratio. When males are made homozygous for the segregation distorter elements, their fecundity is lowered to just that extent expected if each SD were independently causing the sperms carrying the other to dysfunction. In three cases tested, Sd Ac/Ac, Sd Ac/Sd Ac, and Sd Ac St/Sd Ac St, the fecundity of the males is consistent with the dysfunction model, whereas the females are normal.The Sd Ac St/Sd Ac St males are almost completely sterile. They do produce sperms, however, which are motile and which look morphologically normal in the phase contrast microscope. They are transferred to the female during copulation and are stored in apparently normal numbers in the seminal receptacle and spermathecae.
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机译：果蝇雄性对于分离畸变染色体而言是杂合的，显示出繁殖力的降低，这与它们的分离比的畸变程度有关。当使雄性的分离畸变因子纯合子时，如果每个SD独立导致携带另一个精子的精子功能障碍，则它们的繁殖力会降低到预期的程度。在测试的三例Sd Ac / Ac，Sd Ac / Sd Ac和Sd Ac St / Sd Ac St中，雄性的生殖力与功能障碍模型一致，而雌性则正常。圣雄几乎完全不育。但是，它们确实会产生精子，这些精子能够运动并且在相衬显微镜下看起来形态正常。它们在交配过程中被转移到雌性，并以明显的正常数量存储在精囊和精囊中。
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