小柯机器人

美国普林斯顿大学Ricardo Mallarino等研究人员合作发现，Emx2是有袋动物滑翔膜发育和演化的基础。2024年4月24日，《自然》杂志在线发表了这项成果。

研究人员报道了哺乳动物滑翔膜（翼膜）的基因组和发育基础，这是一种在不同种系中反复演化的适应性性状，包括在亲缘关系很近的有袋动物中。通过对来自滑翔和非滑翔物种的15个有袋动物基因组进行比较基因组分析，研究人员发现Emx2基因座在滑翔物种中经历了加速顺式调控演化的特定谱系模式。通过结合表观基因组学、转录组学和袋内有袋动物转基因技术，研究人员发现Emx2是翼膜发育的关键上游调控因子。

此外，研究人员还发现了不同的顺式调控因子，它们可能是导致滑翔物种中Emx2表达水平增加的原因。最后，通过小鼠功能实验，研究人员发现有证据表明，翼膜中的Emx2表达模式可能是在所有哺乳动物的原有程序基础上修改而来的。

总之，这些研究结果表明，翼膜是通过趋同基因组演化过程反复起源的，在这一过程中，Emx2的调控在独立演化的物种中被不同的顺式调控元件所改变。因此，针对同一关键发育基因的不同调控元件可能是，有袋动物基因组中自然选择利用调控演化产生表型新颖性的一种有效策略。

研究人员表示，物种间的表型变异是发育程序演化改变的产物。然而，这些变化如何产生新的形态特征在很大程度上仍不清楚。

附：英文原文

Title: Emx2 underlies the development and evolution of marsupial gliding membranes

Author: Moreno, Jorge A., Dudchenko, Olga, Feigin, Charles Y., Mereby, Sarah A., Chen, Zhuoxin, Ramos, Raul, Almet, Axel A., Sen, Harsha, Brack, Benjamin J., Johnson, Matthew R., Li, Sha, Wang, Wei, Gaska, Jenna M., Ploss, Alexander, Weisz, David, Omer, Arina D., Yao, Weijie, Colaric, Zane, Kaur, Parwinder, Leger, Judy St., Nie, Qing, Mena, Alexandria, Flanagan, Joseph P., Keller, Greta, Sanger, Thomas, Ostrow, Bruce, Plikus, Maksim V., Kvon, Evgeny Z., Aiden, Erez Lieberman, Mallarino, Ricardo

Issue&Volume: 2024-04-24

Abstract: Phenotypic variation among species is a product of evolutionary changes to developmental programs1,2. However, how these changes generate novel morphological traits remains largely unclear. Here we studied the genomic and developmental basis of the mammalian gliding membrane, or patagium—an adaptative trait that has repeatedly evolved in different lineages, including in closely related marsupial species. Through comparative genomic analysis of 15 marsupial genomes, both from gliding and non-gliding species, we find that the Emx2 locus experienced lineage-specific patterns of accelerated cis-regulatory evolution in gliding species. By combining epigenomics, transcriptomics and in-pouch marsupial transgenics, we show that Emx2 is a critical upstream regulator of patagium development. Moreover, we identify different cis-regulatory elements that may be responsible for driving increased Emx2 expression levels in gliding species. Lastly, using mouse functional experiments, we find evidence that Emx2 expression patterns in gliders may have been modified from a pre-existing program found in all mammals. Together, our results suggest that patagia repeatedly originated through a process of convergent genomic evolution, whereby regulation of Emx2 was altered by distinct cis-regulatory elements in independently evolved species. Thus, different regulatory elements targeting the same key developmental gene may constitute an effective strategy by which natural selection has harnessed regulatory evolution in marsupial genomes to generate phenotypic novelty. Patagia—the mammalian gliding membrane—repeatedly originated through a process of convergent genomic evolution, whereby the regulation of Emx2 was altered by distinct cis-regulatory elements in independently evolved species.

DOI: 10.1038/s41586-024-07305-3

Source: https://www.nature.com/articles/s41586-024-07305-3

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