Work

Heteromorphic sex chromosomes: Navigating meiosis without a homologous partner

Year: 2011

Type: review

Abstract: Accurate chromosome segregation during meiosis relies on homology between the maternal and paternal chromosomes. Yet by definition, sex chromosomes of the heterogametic sex lack a homologous partner. Recent studies in a number of systems have shed light on the unique meiotic behavior of heteromorphic sex chromosomes, and highlight both the commonalities and differences in divergent species. During meiotic prophase, the homology-dependent processes of pairing, synapsis, and recombination have been modified in many different ways to ensure segregation of heteromorphic sex chromosomes at the first meiotic division. Additionally, an almost universal feature of heteromorphic sex chromosomes during meiosis is transcriptional silencing, or meiotic sex chromosome inactivation, an essential process proposed to prevent expression of genes deleterious to meiosis in the heterogametic sex as well as to shield unpaired sex chromosomes from recognition by meiotic checkpoints. Comparative analyses of the meiotic behavior of sex chromosomes in nematodes, mammals, and birds reveal important conserved features as well as provide insight into sex chromosome evolution.

Source: Molecular Reproduction and Development

DOI: 10.1002/mrd.21369

Authors: Paula M. Checchi, JoAnne Engebrecht

Institution: University of California, Davis

Language: English

Topic: Genetic and Clinical Aspects of Sex Determination and Chromosomal Abnormalities

Subfield: Genetics

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: green

Funders: National Cancer Institute, National Institute of General Medical Sciences

Awards: G2082376430, G2420462773, G7993322529