Sex chromosomes in some amniotes share linkage homologies with distantly related taxa in regions orthologous to squamate reptile chromosome 2 (SR2) and the snake W sex chromosome. Thus, the SR2 and W chromosomes may formerly have been part of a larger ancestral amniote super-sex chromosome. Comparison of various sex chromosomal linkage homologies in Toxicofera with those in other amniotes offers an excellent model to assess key cytological differences, to understand the mechanisms of amniote sex chromosome evolution in each lineage and the existence of an ancestral amniote super-sex chromosome. Chromosome maps of four species of Toxicofera were constructed using bacterial artificial chromosomes (BACs) derived from chicken and zebra finch libraries containing amniote sex chromosomal linkages. Different macrochromosome linkage homologies were highly conserved among Toxicofera, and at least two BACs (CH261-125F1 and CH261-40D6) showed partial homology with sex chromosomes of amniotes associated with SR2, which supports the hypothesis of an ancestral super-sex chromosome with overlaps of partial linkage homologies. The present data also suggest a possible multiple fission mechanism of an ancestral super-sex chromosome, which resulted in further development of various sex chromosomal linkages of Toxicofera based on particular properties that favored the role of sex chromosomes.

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10577-020-09631-4DOI Listing

Publication Analysis

Top Keywords

sex chromosomes
16
linkage homologies
16
super-sex chromosome
16
amniote super-sex
12
sex chromosomal
12
sex
9
multiple fission
8
chromosomes amniotes
8
chromosome
8
chromosome sr2
8

Similar Publications

Identification of chromosomal abnormalities is an important issue in animal breeding and veterinary medicine. Routine cytogenetic diagnosis of domestic animals began in the 1960s with the aim of identifying carriers of centric fusion between chromosome 1 and 29 in cattle. In the 1970s, chromosome banding techniques were introduced, and in the 1980s, the first cytogenomic techniques, based on the development of locus- and chromosome-specific probes, were used.

View Article and Find Full Text PDF

Background: Deficiency of 17β-hydroxysteroid dehydrogenase type 3 (HSD17B3) is a rare variant of 46,XY disorders of sex development (DSD).

Aim: To give clinical, hormonal and molecular genetic characteristics of cases of 46,XY DSD associated with variants in the HSD17B3 gene.

Materials And Methods: The study included 310 patients with 46,XY DSD for the period from 2015 to 2019.

View Article and Find Full Text PDF

Chromosome-level genome assembly and annotation of the gynogenetic large-scale loach (Paramisgurnus dabryanus).

Sci Data

January 2025

Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture (CAS), Hubei Hongshan Laboratory, Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture and Rural Affairs, The Innovation Academy of Seed Design, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.

The large-scale loach (Paramisgurnus dabryanus; Cypriniformes: Cobitidae) is primarily distributed in East Asia. It is an important economic fish species characterized by fast growth, temperature-dependent sex determination and the ability to breathe air. Currently, molecular mechanism studies related to some aspects such as sex determination, toxicology, feed nutrition, growth and genetic evolution have been conducted.

View Article and Find Full Text PDF

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 PDF

Epigenetic 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 PDF

Want 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!