小柯机器人

美国加州大学Leonid Kruglyak和Longhua Guo共同合作近期取得重要工作进展，他们研究发现了有性涡虫性启动常染色体的岛屿特异性进化。该项研究成果2022年6月1日在线出版于《自然》杂志。

在这里，研究人员分离出单个染色体并使用测序、Hi-C和连锁作图来组装染色体规模的基因组参考。连锁图显示1号染色体上的重组率极低。他们通过对单个精子细胞和卵母细胞进行基因分型来确认1号染色体上的重组受到抑制。研究人员展示了，先前确定的即使在长期近交后仍保持杂合性的基因组区域基本上构成了所有的1号染色体。在野外分离的个体的基因组测序表明，这种现象在撒丁岛和科西嘉岛的种群中特别进化。

研究人员发现，大多数已知的生殖系统主要调节因子位于1号染色体上。他们使用RNA干扰方法敲除具有单倍型偏向表达的基因，导致了更明显的雌性交配器官的形成。在这些观察的基础上，研究人员提出1号染色体是一个性启动的常染色体，为进化为性染色体做好了准备。

据介绍，原产于突尼斯和几个地中海岛屿的涡虫Schmidtea mediterranea的性株是雌雄同体。

附：英文原文

Title: Island-specific evolution of a sex-primed autosome in a sexual planarian

Author: Guo, Longhua, Bloom, Joshua S., Dols-Serrate, Daniel, Boocock, James, Ben-David, Eyal, Schubert, Olga T., Kozuma, Kaiya, Ho, Katarina, Warda, Emily, Chui, Clarice, Wei, Yubao, Leighton, Daniel, Lemus Vergara, Tzitziki, Riutort, Marta, Snchez Alvarado, Alejandro, Kruglyak, Leonid

Issue&Volume: 2022-06-01

Abstract: The sexual strain of the planarian Schmidtea mediterranea, indigenous to Tunisia and several Mediterranean islands, is a hermaphrodite1,2. Here we isolate individual chromosomes and use sequencing, Hi-C3,4 and linkage mapping to assemble a chromosome-scale genome reference. The linkage map reveals an extremely low rate of recombination on chromosome 1. We confirm suppression of recombination on chromosome 1 by genotyping individual sperm cells and oocytes. We show that previously identified genomic regions that maintain heterozygosity even after prolonged inbreeding make up essentially all of chromosome 1. Genome sequencing of individuals isolated in the wild indicates that this phenomenon has evolved specifically in populations from Sardinia and Corsica. We find that most known master regulators5,6,7,8,9,10,11,12,13 of the reproductive system are located on chromosome 1. We used RNA interference14,15 to knock down a gene with haplotype-biased expression, which led to the formation of a more pronounced female mating organ. On the basis of these observations, we propose that chromosome 1 is a sex-primed autosome primed for evolution into a sex chromosome.

DOI: 10.1038/s41586-022-04757-3

Source: https://www.nature.com/articles/s41586-022-04757-3

Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
官方网址：http://www.nature.com/
投稿链接：http://www.nature.com/authors/submit_manuscript.html