Donald Danforth Plant Science Center, St. Louis, Missouri 63132
Department of Plant Biology, University of Georgia, Athens, Georgia 30602.
Plant Cell. 2020 Jun;32(6):1790-1796. doi: 10.1105/tpc.19.00859. Epub 2020 Mar 27.
The origin and early evolution of sex chromosomes have been hypothesized to involve the linkage of factors with antagonistic effects on male and female function. Garden asparagus () is an ideal species to investigate this hypothesis, as the X and Y chromosomes are cytologically homomorphic and evolved from an ancestral autosome pair in association with a shift from hermaphroditism to dioecy. Mutagenesis screens paired with single-molecule fluorescence in situ hybridization directly implicate Y-specific genes that respectively suppress female (pistil) development and are necessary for male (anther) development. Comparison of contiguous X and Y chromosome assemblies shows that hemizygosity underlies the loss of recombination between the genes suppressing female organogenesis () and promoting male function ( []). We also experimentally demonstrate the function of These findings provide direct evidence that sex chromosomes can function through linkage of two sex determination genes.
性染色体的起源和早期进化被假设涉及到对雄性和雌性功能具有拮抗作用的因素的连锁。花园芦笋（）是研究这一假说的理想物种，因为 X 和 Y 染色体在细胞学上是同形的，并且是与雌雄同体向雌雄异体的转变相关联，从一对祖先的常染色体进化而来。诱变筛选与单分子荧光原位杂交相结合，直接涉及到分别抑制雌性（雌蕊）发育和雄性（花药）发育所必需的 Y 染色体特异性基因。对连续的 X 和 Y 染色体组装体的比较表明，半合性是导致抑制雌性器官发生的基因（）和促进雄性功能的基因（）之间重组丧失的基础。我们还通过实验证明了这些发现提供了直接的证据，即性染色体可以通过两个性别决定基因的连锁来发挥作用。
