Genetic conflicts can arise between components of the genome with different inheritance strategies. The germline-restricted chromosome (GRC) of songbirds shows unusual mitotic and meiotic transmission compared with the rest of the genome. It is excluded from somatic cells and maintained only in the germline. It is usually present in one copy in the male germline and eliminated during spermatogenesis, while in the female germline, it usually occurs in two copies and behaves as a regular chromosome. Here, we review what is known about the GRC's evolutionary history, genetic content, and expression and discuss how it may be involved in different types of genetic conflicts. Finally, we interrogate the potential role of the GRC in songbird germline development, highlighting several unsolved mysteries.

Centre for Molecular Biodiversity Research Leibniz Institute for the Analysis of Biodiversity Change Adenauerallee 127 53113 Bonn Germany; Institute of Evolutionary Biology and Ecology University of Bonn An der Immenburg 1 53121 Bonn Germany

Centre for Molecular Biodiversity Research Leibniz Institute for the Analysis of Biodiversity Change Adenauerallee 127 53113 Bonn Germany; Institute of Evolutionary Biology and Ecology University of Bonn An der Immenburg 1 53121 Bonn Germany; Department of Organismal Biology Systematic Biology Evolutionary Biology Centre Science for Life Laboratory Uppsala University Uppsala Sweden

Centre for Molecular Biodiversity Research Leibniz Institute for the Analysis of Biodiversity Change Adenauerallee 127 53113 Bonn Germany; School of Biological Sciences University of East Anglia Norwich UK

Department of Ornithology Max Planck Institute for Biological Intelligence 82319 Seewiesen Germany

Department of Zoology Faculty of Science Charles University Prague Czech Republic

Citace poskytuje Crossref.org

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