CHROMATIN DIMINUTION AND A CHROMOSOMAL MECHANISM OF SEXUAL-DIFFERENTIATION IN STRONGYLOIDES-PAPILLOSUS
CHROMATIN DIMINUTION AND A CHROMOSOMAL MECHANISM OF SEXUAL-DIFFERENTIATION IN STRONGYLOIDES-PAPILLOSUS
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DOI：
10.1007/bf00330626
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发表时间：
1979-01-01
期刊：
影响因子：
1.6
通讯作者：
SULSTON, JE
中科院分区：
文献类型：
--
作者：
ALBERTSON, DG;NWAORGU, OC;SULSTON, JE
从感染S.将乳头状突起挤压并进行核型分析。它们含有具有2条长染色体和2条中等大小染色体（2L2M）或1条长染色体、3条中等大小染色体和1条短染色体（L3MS）的细胞。根据卵母细胞成熟分裂前中期的染色体形态，可以区分两种类型的寄生雌性腺。在一个生殖腺中，所有的卵母细胞都含有2条不成对的长染色体和2条不成对的中等大小的染色体，或2条不成对的中等大小的染色体和2条不成对的染色体，它们在一个区域内被分割成珠状。在有丝分裂孤雌生殖的成熟分裂中，珠粒似乎从1条染色体上丢失。这产生了一个中等大小和较短的染色体，它与未减少的染色体一起构成了L3MS核型。具有珠状卵母细胞染色体的动物产卵，发育成雄性。由于在有丝分裂单性生殖的成熟分裂中发生的染色质减少，雄性可能是异形的长同源物。
Eggs obtained from feces of rabbits infected with S. papillosus were squashed and the karyotypes were determined. They contained cells with either 2 long and 2 medium sized chromosomes (2L2M) or 1 long, 3 medium and 1 short chromosome (L3MS). Two types of parasitic female gonad could be distinguished on the basis of oocyte chromosome morphology at prometaphase of the maturation division. All the occytes in a gonad contained either 2 upaired long chromosomes and 2 unpaired medium sized chromosomes, or 2 unpaired medium sized chromosomes and 2 unpaired chromosomes segmented into beads in 1 region. At the maturation division in mitotic parthenogenesis the beads appeared to be lost from 1 of the chromosomes. This generated a medium sized and a shorter chromosome, which together with the undiminished chromosomes made up the L3MS karyotype. Animals with beaded oocyte chromosomes lay eggs that develop into males. Males may be heteromorphic for the long homolog due to the chromatin diminution that occurs in the maturation division of mitotic parthenogenesis.