Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; FAFU and UIUC-SIB Joint Center for Genomics and Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China.
Plant Sci. 2014 Mar;217-218:56-62. doi: 10.1016/j.plantsci.2013.10.018. Epub 2013 Nov 5.
Unisexuality in flowering plants evolved from a hermaphrodite ancestor. Transition from hermaphrodite to unisexual flowers has occurred multiple times across the different lineages of the angiosperms. Sexuality in plants is regulated by genetic, epigenetic and physiological mechanisms. The most specialized mechanism of sex determination is sex chromosomes. The sex chromosomes ensure the stable segregation of sexual phenotypes by preventing the recombination of sex determining genes. Despite continuous efforts, sex determining genes of dioecious plants have not yet been cloned. Concerted efforts with various model systems are necessary to understand the complex mechanism of sex determination in plants. Papaya (Carica papaya L.) is a tropical fruit tree with three sex forms, male, hermaphrodite, and female. Sexuality in papaya is determined by an XY chromosome system that is in an early evolutionary stage. The male and hermaphrodite of papaya are controlled by two different types of Y chromosomes: Y and Y(h). Large amounts of information in the area of genetics, genomics, and epigenetics of papaya have been accumulated over the last few decades. Relatively short lifecycle, small genome size, and readily available genetic and genomic resources render papaya an excellent model system to study sex determination and sex chromosomes in flowering plants.
在有花植物中，雌雄同体是从雌雄同体祖先进化而来的。在被子植物的不同谱系中，雌雄同体向单性花的转变已经发生了多次。植物的性别是由遗传、表观遗传和生理机制调控的。性别决定最特化的机制是性染色体。性染色体通过防止性别决定基因的重组，确保了性表型的稳定分离。尽管人们不断努力，但雌雄异株植物的性别决定基因尚未被克隆。需要与各种模式系统共同努力，以了解植物性别决定的复杂机制。木瓜（Carica papaya L.）是一种热带果树，有三种性别形式，雄性、雌雄同体和雌性。木瓜的性别由一个 XY 染色体系统决定，该系统处于早期进化阶段。木瓜的雄性和雌雄同体由两种不同类型的 Y 染色体控制：Y 和 Y(h)。在过去几十年中，木瓜在遗传学、基因组学和表观遗传学领域积累了大量信息。相对较短的生命周期、较小的基因组大小以及现成的遗传和基因组资源，使木瓜成为研究有花植物性别决定和性染色体的优秀模式系统。
