【生物資源学先端セミナー】

　演　題：「Evolution of a plant sex chromosome driven
                  by expanding pericentromeric recombination suppression」
　　　　　　　　　　　　　　　　　
　講　師：Prof. Dmitry A. Filatov     　   
               Department of Biology, University of Oxford, UK

　概要：
　

Sex chromosomes independently evolved hundreds of times in many organisms. Typically, they evolve from a pair of autosomes that acquire sex-determining gene(s) and evolve recombination suppression in one of the sexes. Despite independent evolution, sex chromosomes have similar properties - the sex-specific Y-chromosome lacks recombination and undergoes genetic degeneration,while the X-chromosome continues to recombine and remains gene-rich. This represents an impressive example of convergent evolution and the processes driving it are not fully understood. We use recently evolved sex chromosomes in a plant White campion (Silene latifolia) to study how sex chromosomes originate and evolve. The Y-chromosome in this species is the largest in the genome and is already partly degenerate. Our recent analysis of this 3Gb-long genome integrated with high-density genetic map revealed how the sex chromosomes evolved in this species. The 15Mb-long non-recombining sex-determining region (SDR) initially evolved at an actively recombining end of the proto-sex chromosomes about 11 million years ago. This was followed by a massive SDR expansion about 6 million years ago and further small expansion about 100 thousand years ago. Our analysis indicates that the SDR expansion was driven by the growing pericentromeric recombination suppression that eventually reached the SDR at the end of the sex chromosome. This contradicts the popular belief that SDR expansions on sex chromosomes are typically driven by sexually antagonistic selection, and provides a new model for SDR expansion during sex chromosome evolution.

Oxford大学のFilatov教授が、植物性染色体の進化について最新の研究成果を踏
まえて紹介してくれます。　
Filatov教授はとても気さくで優しい先生です。皆様、お誘い合わせのうえご参
加ください。

　日時： 9月11日 （月曜日） 13:00 ～ 14:30
  
　場所：生物資源学部棟 1F 会議室
　
　連絡先： 担当教員名　風間　裕介　(内線：3618）

　ポスターはこちらのリンクからも見られます。
　https://drive.google.com/file/d/1hQBI_XvFjMCB1rVvZjARv_W6E9KHPl4D/view?usp=sharing

教員・院生・学部生のみなさんの来聴を歓迎します！