Discovery of XY Sex Chromosomes in Mauremys mutica Provides Insights Into the Role of KDM6B Gene in Coexistence of Temperature-Dependent and Genetic Sex Determination
Jianjun Liu, Siqi Liu, Jinxiu Dong, Min Tang, Taiyue Li, Jiahui Li, Xinjiang Bu, Xingquan Xia, Huaxing Zhou, Liuwang Nie
{"title":"Discovery of XY Sex Chromosomes in Mauremys mutica Provides Insights Into the Role of KDM6B Gene in Coexistence of Temperature-Dependent and Genetic Sex Determination","authors":"Jianjun Liu, Siqi Liu, Jinxiu Dong, Min Tang, Taiyue Li, Jiahui Li, Xinjiang Bu, Xingquan Xia, Huaxing Zhou, Liuwang Nie","doi":"10.1111/mec.17710","DOIUrl":null,"url":null,"abstract":"<div>\n \n <p>The Asian yellow pond turtle (<i>Mauremys mutica</i>) has long been thought to lack dimorphic sex chromosomes, with prevailing theories suggesting a solely temperature-dependent sex determination (TSD) system. In this study, a male chromosome-level genomic sequence with a contig N50 of ~23.59 Mb was generated using a combination of both Nanopore and Hi-C sequencing technologies. We utilise a combination of bioinformatics and cytogenetic experimental validation to demonstrate that this species indeed possesses XY chromosomes, thereby correcting a longstanding misconception. The results suggest that the X chromosome of the Asian yellow pond turtle originated independently during later stages of evolution and underwent chromosomal rearrangements. Notably, it was observed that the sex chromosomes exhibited a significant repeat expansion, with 95.9% comprising repetitive sequences. This expansion is primarily driven by LINE/CR1 repeats, which account for 55.2% of the total length of the X chromosome. We found that the X chromosome underwent a lower rate of adaptive evolution, supporting the concept of the “slower-X” effect. We present a novel model concerning the <i>KDM6B</i>, which is located on both XY chromosomes, mediates a sex determination mechanism that coexists with TSD + XY in turtles. This study paves the way for further exploration into the complexities of sex determination and the evolutionary dynamics of sex chromosomes in turtles and potentially other reptiles.</p>\n </div>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":"34 7","pages":""},"PeriodicalIF":4.5000,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Molecular Ecology","FirstCategoryId":"99","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1111/mec.17710","RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
The Asian yellow pond turtle (Mauremys mutica) has long been thought to lack dimorphic sex chromosomes, with prevailing theories suggesting a solely temperature-dependent sex determination (TSD) system. In this study, a male chromosome-level genomic sequence with a contig N50 of ~23.59 Mb was generated using a combination of both Nanopore and Hi-C sequencing technologies. We utilise a combination of bioinformatics and cytogenetic experimental validation to demonstrate that this species indeed possesses XY chromosomes, thereby correcting a longstanding misconception. The results suggest that the X chromosome of the Asian yellow pond turtle originated independently during later stages of evolution and underwent chromosomal rearrangements. Notably, it was observed that the sex chromosomes exhibited a significant repeat expansion, with 95.9% comprising repetitive sequences. This expansion is primarily driven by LINE/CR1 repeats, which account for 55.2% of the total length of the X chromosome. We found that the X chromosome underwent a lower rate of adaptive evolution, supporting the concept of the “slower-X” effect. We present a novel model concerning the KDM6B, which is located on both XY chromosomes, mediates a sex determination mechanism that coexists with TSD + XY in turtles. This study paves the way for further exploration into the complexities of sex determination and the evolutionary dynamics of sex chromosomes in turtles and potentially other reptiles.
期刊介绍:
Molecular Ecology publishes papers that utilize molecular genetic techniques to address consequential questions in ecology, evolution, behaviour and conservation. Studies may employ neutral markers for inference about ecological and evolutionary processes or examine ecologically important genes and their products directly. We discourage papers that are primarily descriptive and are relevant only to the taxon being studied. Papers reporting on molecular marker development, molecular diagnostics, barcoding, or DNA taxonomy, or technical methods should be re-directed to our sister journal, Molecular Ecology Resources. Likewise, papers with a strongly applied focus should be submitted to Evolutionary Applications. Research areas of interest to Molecular Ecology include:
* population structure and phylogeography
* reproductive strategies
* relatedness and kin selection
* sex allocation
* population genetic theory
* analytical methods development
* conservation genetics
* speciation genetics
* microbial biodiversity
* evolutionary dynamics of QTLs
* ecological interactions
* molecular adaptation and environmental genomics
* impact of genetically modified organisms