Sex determination in polyploids of Caenorhabditis elegans.
Sex determination in polyploids of Caenorhabditis elegans.
复制标题
秀丽隐杆线虫多倍体的性别决定。
DOI：
10.1093/genetics/137.2.467
复制
发表时间：
1994
期刊：
影响因子：
3.3
通讯作者：
Meneely,PM
中科院分区：
文献类型：
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作者：
Meneely,PM
在秀丽线虫中，具有两条X染色体的三倍体动物(符号为3A；2X)为雄性。然而，这些三倍体雄性可以通过使他们成为隐性剂量补偿突变的突变，通过增加X染色体复制或通过显微注射被称为女性化元素的特定DNA序列来女性化。这些处理都不会影响二倍体雄性。这项研究探索了多倍体中这些处理的几个方面。剂量补偿突变体表现出强烈的母性效应，母亲体内任何剂量补偿基因功能的降低都会导致3A；2X动物的性别逆转。同样，所有测试的X染色体复制都会导致许多3A；2X动物的性别反转和间性发育。显微注射女性化元素DNA不会导致广泛的性别逆转，但确实会导致3A；2X动物的双性发育。X染色体复制和显微注射雌性化元件都没有显示剂量补偿突变体的极端母性效应，尽管有间接证据表明雌性化元件的母性效应。特别是，为了使三倍体男性女性化，需要显微注射的女性化元素DNA非常少，远远低于稳定遗传所需的DNA，这意味着女性化元素可以在母亲的性腺中发挥作用。然而，即使是非常高浓度的显微注射雌性化元素也不会影响二倍体雄性的性别决定，这表明它们不是X/A比率分子的一部分。此外，没有一对X染色体复制使二倍体雄性雌性化，这表明这些复制都不包含X/A比率的分子。相反，我推断，一个尚未定义的X连锁基因必须存在于两个拷贝中，以便两性体发育，或者两个X染色体可能相互作用。
In Caenorhabditis elegans triploid animals with two X chromosomes (symbolized 3A;2X) are males. However, these triploid males can be feminized by making them mutant for recessive dosage compensation mutations, by adding X chromosome duplications or by microinjecting particular DNA sequences termed feminizing elements. None of these treatments affects diploid males. This study explores several aspects of these treatments in polyploids. The dosage compensation mutants exhibit a strong maternal effect, such that reduction of any of the dosage compensation gene functions in the mother leads to sex reversal of 3A;2X animals. Likewise, all X chromosome duplications tested cause both sex reversal and intersexual development of many 3A;2X animals. Microinjected feminizing element DNA does not cause extensive sex reversal, but does result in intersexual development in 3A;2X animals. Neither X chromosome duplications nor microinjected feminizing elements show that extreme maternal effect of the dosage compensation mutants, although there is indirect evidence for a maternal effect of the feminizing elements. In particular, very little feminizing element DNA needs to be microinjected in order to feminize triploid males, far less than what is needed for stable inheritance, implying that feminizing elements can work within the mother's gonad. However, even very high concentrations of microinjected feminizing elements do not affect sex determination in diploid males, suggesting that they are not part of the numerator of the X/A ratio. In addition, no pair of X chromosome duplications feminizes diploid males, suggesting that none of these duplications contains a numerator of the X/A ratio. Instead, I infer that an X-linked locus, as yet undefined, must be present in two copies for hermaphrodite development to ensue or that the two X chromosomes might interact.