AI Article Synopsis
Article Abstract
A major goal of genomic and reproductive biology is to understand the evolution of sex determination and sex chromosomes. Species of the 2 genera of the Salamander family Proteidae - Necturus of eastern North America, and Proteus of Southern Europe - have similar-looking karyotypes with the same chromosome number (2n = 38), which differentiates them from all other salamanders. However, Necturus possesses strongly heteromorphic X and Y sex chromosomes that Proteus lacks. Since the heteromorphic sex chromosomes of Necturus were detectable only with C-banding, we hypothesized that we could use C-banding to find sex chromosomes in Proteus. We examined mitotic material from colchicine-treated intestinal epithelium, and meiotic material from testes in specimens of Proteus, representing 3 genetically distinct populations in Slovenia. We compared these results with those from Necturus. We performed FISH to visualize telomeric sequences in meiotic bivalents. Our results provide evidence that Proteus represents an example of sex chromosome turnover in which a Necturus-like Y-chromosome has become permanently translocated to another chromosome converting heteromorphic sex chromosomes to homomorphic sex chromosomes. These results may be key to understanding some unusual aspects of demographics and reproductive biology of Proteus, and are discussed in the context of models of the evolution of sex chromosomes in amphibians.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1159/000446882 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
A Novel Large Duplication on the X Chromosome as a Cause of Familial Generalized Dystonia: A Case Report.
Int J Mol Sci
January 2025
Department of Neurology, Centro Hospitalar Universitário de Santo António, Unidade Local de Saúde de Santo António, 4099-001 Porto, Portugal.
Chromosomal aberrations are rare but known causes of movement disorders, presenting with broad phenotypes in which dystonia may be predominant. During the investigation of such cases, chromosomal studies are not often considered as a first approach. In this article, the authors describe a family affected by a generalized form of dystonia, evolving from a focal phenotype, for which a new X chromosome large duplication was found to be the likely causative, therefore highlighting the role of such studies when facing complex movement disorders.
View Article and Find Full Text PDFEpigenetic Mechanisms Underlying Sex Differences in Neurodegenerative Diseases.
Biology (Basel)
January 2025
Laboratory of Medical Genetics, Department of Translational Research and of New Surgical and Medical Technologies, Medical School, University of Pisa, Via Roma 55, 56126 Pisa, Italy.
Neurodegenerative diseases are characterized by profound differences between females and males in terms of incidence, clinical presentation, and disease progression. Furthermore, there is evidence suggesting that differences in sensitivity to medical treatments may exist between the two sexes. Although the role of sex hormones and sex chromosomes in driving differential susceptibility to these diseases is well-established, the molecular alterations underlying these differences remain poorly understood.
View Article and Find Full Text PDFSex chromosomes and sex hormones differently shape microglial properties during normal physiological conditions in the adult mouse hippocampus.
J Neuroinflammation
January 2025
Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.
The brain presents various structural and functional sex differences, for which multiple factors are attributed: genetic, epigenetic, metabolic, and hormonal. While biological sex is determined by both sex chromosomes and sex hormones, little is known about how these two factors interact to establish this dimorphism. Sex differences in the brain also affect its resident immune cells, microglia, which actively survey the brain parenchyma and interact with sex hormones throughout life.
View Article and Find Full Text PDFEvolutionary divergence between homologous X-Y chromosome genes shapes sex-biased biology.
Nat Ecol Evol
January 2025
Section on Developmental Neurogenomics, Human Genetics Branch, NIMH IRP, NIH, Bethesda, MD, USA.
Sex chromosomes are a fundamental aspect of sex-biased biology, but the extent to which homologous X-Y gene pairs ('the gametologs') contribute to sex-biased phenotypes remains hotly debated. Although these genes tend to exhibit large sex differences in expression throughout the body (XX females can express both X members, and XY males can express one X and one Y member), there is conflicting evidence regarding the degree of functional divergence between the X and Y members. Here we develop and apply co-expression fingerprint analysis to characterize functional divergence between the X and Y members of 17 gametolog gene pairs across >40 human tissues.
View Article and Find Full Text PDFThe X chromosome's influences on the human brain.
Sci Adv
January 2025
Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
Genes on the X chromosome are extensively expressed in the human brain. However, little is known for the X chromosome's impact on the brain anatomy, microstructure, and functional networks. We examined 1045 complex brain imaging traits from 38,529 participants in the UK Biobank.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!