POLYPLOIDS AND SEX DETERMINATION IN CAENORHABDITIS ELEGANS

[摘要] Tetraploid stocks of Caenorhabditis elegans var. Bristol carrying autosomal and X -linked markers have been produced. Tetraploid hermaphrodites fall into two categories: those that give about 1% male self-progeny and those that give 25 to 40% male self-progeny, The former are basically 4A;4X —four sets of autosomes and four sex chromosomes—and the latter are 4A;3X . Males are 4A;2X . (Diploid hermaphrodites are 2A;2X ; males are 2A;IX .) Triploids wsre produced by crossing tetraploid hermaphrodites and diploid males. Triploids of composition 3A;3X are hermaphrodites; 3A;2X animals are fertile males. Different X -chromosome duplications were added to a 3A;2X chromosome constitution to increase the X -to-autosome ratio. Based on the resulting sexual phenotypes, we conclude that there exists on the C. elegans X chromosome at least three (and perhaps many mare) dose-sensitive sites that act cumulatively in determining sex.

[学科分类] 医学（综合）