Researcher at the Laboratory for Environmental Monitoring of NPP Regions and Bioindication, Ph.D. Sergey Anatolyevich Simanovsky became a member of a large collaboration of European and American scientists on the cytogenomic study of the guiding role of B chromosomes in male development in Astyanax mexicanus (Characiformes). The results of the study are published in Current Biology (Q1 WoS, IF = 10.834).
Part of the work of S.A. Simanovsky was the study of synaptonemal complexes in prophase I of meiosis in A. mexicanus males with B-chromosomes in somatic cells. The presence of single B-chromosomes was also found in spermatocytes. At the pachytene stage of prophase I of meiosis, B chromosomes were identified as univalents that did not interact with autosomal bivalents. This part of the research was carried out at the expense of the RFBR's own grant, which is reflected in the “Acknowledgments” article.
The main result of the study was the discovery on the B chromosomes of A. mexicanus of two loci of the gdf6b gene, a putative master gene for sex determination. It was found that gdf6b is expressed only in the testes and determines the development of the male pattern. When this gene is knocked out, a sex change occurs.
Imarazene B., Du K., Beille S., Jouanno E., Feron R., Pan Q., Torres-Paz J., Lopez-Roques C., Castinel A., Gil L., Kuchly C., Donnadieu C., Parrinello H., Journot L., Cabau C., Zahm M., Klopp C., Pavlica T., Al-Rikabi A., Liehr T., Simanovsky S.A., Bohlen J., Sember A., Perez J., Veyrunes F., Mueller T.D., Postlethwait J.H., Schartl M., Herpin A., Rétaux S., Guiguen Ya.. A supernumerary “B-sex” chromosome drives male sex determination in the Pachón cavefish, Astyanax mexicanus. Current Biology, Volume 31, Issue 21, 2021, Pages 4800-4809.e9, https://doi.org/10.1016/j.cub.2021.08.030