Collaborative Research: Comparative Investigation of Incipient Sex Chromosome Evolution in the genus Asparagus

虽然不同的性染色体是多种生物细胞核的一个显著特征，但动物、植物和真菌中不同性别和性染色体起源的进化过程在很大程度上仍然未知。在许多开花植物谱系中，不同性别（即雄性个体和雌性个体）的独立起源为生物学家提供了研究性别决定和性染色体进化的各个阶段的机会。例如，在过去的200万年里，芦笋属已经进化出了不同的性别，负责决定性别的基因已经被定位到相对较小的区域，否则染色体就会重组。pi、Leebens-Mackand Pires将对花园芦笋中该区域新进化的雌性（原x）和雄性（原y）形式进行测序，以检验有关早期性染色体进化的假设，并确定可能负责性别决定的候选基因。通过研究开花植物中影响雄性和雌性功能的基因之间的重组抑制机制，本项目的结果将对作物改良和形成基因组结构的基本过程产生影响。本科生也将接受基因组注释和比较基因组学方面的培训。

While distinctive sex chromosomes are a conspicuous feature of the nuclei of diverseorganisms, the evolutionary processes responsible for the origins of separate gendersand sex chromosomes in animals, plants and fungi remain largely unknown. Theindependent origin of separate sexes (that is, male individuals and female individuals) inmany flowering plant lineages provides biologists with an opportunity to investigatevarious stages in the evolution of gender determination and sex chromosomes. Forexample, separate sexes have evolved within the last two million years in the genusAsparagus and the genes responsible for gender determination have been mapped to arelatively small region on otherwise recombining chromosomes. PIs, Leebens-Mackand Pires will sequence across the newly evolving female (proto-X) and male (proto-Y)forms of this region in garden asparagus in order to test hypotheses concerning theearly evolution of incipient sex chromosomes and to identify candidate genes that maybe responsible for gender determination.By investigating the mechanisms that promote repression of recombination betweengenes influencing male and female function in flowering plants, the results from thisproject will have implications for crop improvement and the fundamental processes thatshape genome structure. Undergraduate students will also be trained in genomeannotation and comparative genomics.