The Structure and Function of Sex Chromosomes in Plants

性别决定的稳定遗传机制是 在一个物种中保持两性分离的先决条件。 这反过来又要求那些促进或抑制 雌性和雄性表达位于同一染色体上。 染色体性别决定在植物中并不常见，但却广泛存在 在动物中，几乎总是伴随着形态 X和Y染色体的分化。 相对 植物性染色体最近的起源意味着，在许多 例，密切相关的物种，缺乏性染色体，也 存在. 性染色体变异的存在 在一个密切相关的植物群内的分化提供了 研究性染色体起源的模型系统。 Silene中的Y染色体将被研究作为一种测试， 关于其结构、功能和 进化发展 为了追溯 在Y中，将产生基于DNA的遗传标记集合 从使用流式细胞术分离的Y染色体， 用限制酶消化。 产生的Y染色体特异DNA 探针将与S. 宽叶以及相关的物种，有和没有单独的 性别的预期是，Y染色体将有一些 与X . 非同源光环 以防止会破坏“活跃Y”性别的重组 S的测定。宽叶。 第二，S. Latifolia被认为是部分功能失调的。 一 Y染色体对花发育影响的数量遗传分析 表型将使用在一系列 关系程度（例如父母：后代， 祖父母：孙子女、半同胞等）。 本研究将 整合不同的方法，从分子细胞遗传学到 数量遗传学，并将大大提高我们的理解 性别分化的遗传事件。

A stable genetic mechanism for sex determination is a prerequisite for the maintenance of separate sexes in a species. This in turn requires that those genes promoting or suppressing female and male expression be located on the same chromosome. Chromosomal sex determination, uncommon in plants, is widespread in animals and is almost invariably accompanies by morphological differentiation of the X and Y chromosomes. The relatively recent origin of sex chromosomes in plants means that, in many cases, closely related species which lack sex chromosomes, also exist. The existence of variation in sex chromosome differentiation within a closely related group of plants provide a model system for the study of the origin of sex chromosomes. The Y chromosomes in Silene will be studied as a test of theoretical predictions concerning their structure, function, and evolutionary development. To trace the evolutionary history of the Y, a collection DNA-based genetic markers will be generated from Y chromosomes isolated using flow cytometry and subsequently digested using restriction enzymes. The resulting Y-specific DNA probes will be cross-hybridized with metaphase chromosomes of S. latifolia as well as related species with and without separate sexes the expectation is that the Y chromosome will have some regions of similarity with the X . Auras of non-homology serve to prevent recombination that would disrupt the 'active Y' sex determination of S. latifolia. Second, the Y chromosome in S. latifolia is believed to be partially dysfunctional. A quantitative genetic analysis of Y chromosome effects on floral phenotypes will be using performed regressions over a range of degrees of relationship (e.g. parent: offspring, grandparent:grand-offspring, half-sib, etc.). This study will integrate diverse approaches, from molecular cytogenetics to quantitative genetics, and will greatly enhance our understanding of the genetic events involved in sex differentiation.