caa a22 4500 445821353 CHVBK 20180317145245.0 cr unu---uuuuu 170323e20110601xx s 000 0 eng 10.1007/s00239-011-9449-0 doi (NATIONALLICENCE)springer-10.1007/s00239-011-9449-0 Absence of Positive Selection on Centromeric Histones in Tetrahymena Suggests Unsuppressed Centromere-Drive in Lineages Lacking Male Meiosis [Elektronische Daten] [Nels Elde, Kevin Roach, Meng-Chao Yao, Harmit Malik] Centromere-drive is a process where centromeres compete for transmission through asymmetric "female" meiosis for inclusion into the oocyte. In symmetric "male" meiosis, all meiotic products form viable germ cells. Therefore, the primary incentive for centromere-drive, a potential transmission bias, is believed to be missing from male meiosis. In this article, we consider whether male meiosis also bears the primary cost of centromere-drive. Because different taxa carry out different combinations of meiotic programs (symmetric+asymmetric, symmetric only, asymmetric only), it is possible to consider the evolutionary consequences of centromere-drive in the context of these differing systems. Groups with both types of meiosis have large, rapidly evolving centromeric regions, and their centromeric histones (CenH3s) have been shown to evolve under positive selection, suggesting roles as suppressors of centromere-drive. In contrast, taxa with only symmetric male meiosis have shown no evidence of positive selection in their centromeric histones. In this article, we present the first evolutionary analysis of centromeric histones in ciliated protozoans, a group that only undergoes asymmetric "female" meiosis. We find no evidence of positive selection acting on CNA1, the CenH3 of Tetrahymena species. Cytological observations of a panel of Tetrahymena species are consistent with dynamic karyotype evolution in this lineage. Our findings suggest that defects in male meiosis, and not mitosis or female meiosis, are the primary selective force behind centromere-drive suppression. Our study raises the possibility that taxa like ciliates, with only female meiosis, may therefore undergo unsuppressed centromere drive. The Author(s), 2011 Tetrahymena thermophila nationallicence Positive selection nationallicence Phylogeny nationallicence Asymmetric female meiosis nationallicence Karyotype nationallicence Elde Nels Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue N. A2-205, 98109, Seattle, WA, USA aut Roach Kevin Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue N. A2-205, 98109, Seattle, WA, USA aut Yao Meng-Chao Institute of Molecular Biology, Academia Sinica, 11529, Taipei, Taiwan aut Malik Harmit Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue N. A2-205, 98109, Seattle, WA, USA aut Journal of Molecular Evolution Springer-Verlag 72/5-6(2011-06-01), 510-520 0022-2844 72:5-6<510 2011 72 239 https://doi.org/10.1007/s00239-011-9449-0 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00239-011-9449-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Elde Nels Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue N. A2-205, 98109, Seattle, WA, USA aut NATIONALLICENCE 700 1- Roach Kevin Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue N. A2-205, 98109, Seattle, WA, USA aut NATIONALLICENCE 700 1- Yao Meng-Chao Institute of Molecular Biology, Academia Sinica, 11529, Taipei, Taiwan aut NATIONALLICENCE 700 1- Malik Harmit Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue N. A2-205, 98109, Seattle, WA, USA aut NATIONALLICENCE 773 0- Journal of Molecular Evolution Springer-Verlag 72/5-6(2011-06-01), 510-520 0022-2844 72:5-6<510 2011 72 239 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer