由于绿鬣蜥（Anolis carolinensis）表现出其X染色体的完全剂量补偿，研究人员测试了是否有长非编码RNA（lncRNA）参与其中。研究人员发现了一种古老的lncRNA（MAYEX），它在超过8900万年前获得了雄性特异性表达。
MAYEX与乙酰化组蛋白H4第16位赖氨酸（H4K16ac）表观遗传标记演化出显著的关联，并能够将其基因座与整个X染色体环绕连接以增强表达水平。MAYEX是首个与爬行动物剂量补偿机制相关的lncRNA，负责平衡性染色体的表达。
研究人员表示，lncRNA是性染色体的重要调控元件，能够在雄性和雌性之间平衡基因表达水平。XIST、RSX和roX2分别调控着胎盘哺乳动物、有袋类动物和果蝇的X染色体。
附：英文原文
Title: MAYEX is an old long noncoding RNA recruited for X chromosome dosage compensation in a reptile
Author: Mariela Tenorio, Samantha Cruz-Ruiz, Sergio Encarnación-Guevara, Magdalena Hernández, Jose Antonio Corona-Gomez, Fania Sheccid-Santiago, Joanna Serwatowska, Sinai López-Perdomo, Cynthia D. Flores-Aguirre, Diego M. Arenas-Moreno, Robert J. Ossiboff, Fausto Méndez-de-la-Cruz, Selene L. Fernandez-Valverde, Mario Zurita, Katarzyna Oktaba, Diego Cortez
Issue&Volume: 2024-09-20
Abstract: Long noncoding RNAs (lncRNAs) are essential regulatory elements of sex chromosomes that act to equalize gene expression levels between males and females. XIST, RSX, and roX2 regulate X chromosomes in placental mammals, marsupials, and Drosophila, respectively. Because the green anole (Anolis carolinensis) shows complete dosage compensation of its X chromosome, we tested whether a lncRNA was involved. We found an ancient lncRNA, MAYEX, that gained male-specific expression more than 89 million years ago. MAYEX evolved a notable association with the acetylated histone 4 lysine 16 (H4K16ac) epigenetic mark and the ability to loop its locus to the totality of the X chromosome to increase expression levels. MAYEX is the first lncRNA in reptiles linked to a dosage compensation mechanism that balances the expression of sex chromosomes.
DOI: adp1932
Source: https://www.science.org/doi/10.1126/science.adp1932