Multicellular organisms usually have the same genetic information in all cells of an individual. There is, however, a growing list of exceptions, where parts of the genome are removed from some cells. This programmed DNA elimination has evolved multiple times across animals and plants, but we still know very little about its function, proximate mechanisms and evolutionary significance. This project aims to study programmed DNA elimination in songbirds, where a whole chromosome is removed from the somatic cells during embryogenesis and from the male germ cells during spermatogenesis. This germline-restricted chromosome (GRC) shows extraordinarily dynamic evolution and unstable meiotic and mitotic inheritance. Yet, it has not been lost from the genome for over 30 million years of songbird evolution, suggesting that it has an important function. The goal of this project is to reveal cellular mechanisms of the GRC elimination from the somatic cells as well as from male germ cells and clarify modes of GRC inheritance. This will be achieved using combination of advanced cytogenetic, immunohistological and genomic approaches. The project will be performed on two model organisms, the two closely related nightingale species of the genus Luscinia and several estrildid finches of the genus Lonchura.
Five relevant publications of the research group:
Schlebusch SA, Rídl J, Poignet M, Ruiz-Ruano FJ, Reif J, Pačes J, Albrecht T, Suh A, Reifová R (2022). Rapid gene content turnover on the germline-restricted chromosome in songbirds. Nature Communications (in revision). Preprint: https://doi.org/10.21203/rs.3.rs-1359388/v1
Sotelo-Muñoz M, Poignet M, Albrecht T, Kauzál O, Dedukh D, Schlebusch SA, Janko K, Reifová R. (2022). Germline-restricted chromosome shows remarkable variation in size among closely related passerine species. Chromosoma 131(1-2):77-86.
Borodin P, Chen A, Forstmeier W, Fouché S, Malinovskaya L, Pei Y, Reifová R, Ruiz-Ruano FJ, Schlebusch SA, Sotelo-Muñoz M, Torgasheva A, Vontzou N, Suh A. (2022): Mendelian nightmares: The germline-restricted chromosome of songbirds. Chromosome Research 30(2-3):255-272.
Johnson Pokorná M and Reifová R (2021). Evolution of B chromosomes: from dispensable parasitic chromosomes to essential genomic players. Frontiers in Genetics 12:727570.
Poignet M, Johnson Pokorná M, Altmanová M, Majtánová Z, Dedukh D, Albrecht T, Reif J, Osiejuk TS, Reifová R. (2021). Comparison of Karyotypes in Two Hybridizing Passerine Species: Conserved Chromosomal Structure but Divergence in Centromeric Repeats. Frontiers in Genetics 12:768987.Apply to the project