Stowers Institute for Medical Research, Kansas City, Missouri, United States of America.
Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas, United States of America.
PLoS Genet. 2020 Feb 7;16(2):e1008350. doi: 10.1371/journal.pgen.1008350. eCollection 2020 Feb.
Meiotic drivers are selfish alleles that can force their transmission into more than 50% of the viable gametes made by heterozygotes. Meiotic drivers are known to cause infertility in a diverse range of eukaryotes and are predicted to affect the evolution of genome structure and meiosis. The wtf gene family of Schizosaccharomyces pombe includes both meiotic drivers and drive suppressors and thus offers a tractable model organism to study drive systems. Currently, only a handful of wtf genes have been functionally characterized and those genes only partially reflect the diversity of the wtf gene family. In this work, we functionally test 22 additional wtf genes for meiotic drive phenotypes. We identify eight new drivers that share between 30-90% amino acid identity with previously characterized drivers. Despite the vast divergence between these genes, they generally drive into >85% of gametes when heterozygous. We also identify three wtf genes that suppress other wtf drivers, including two that also act as autonomous drivers. Additionally, we find that wtf genes do not underlie a weak (64% allele transmission) meiotic driver on chromosome 1. Finally, we find that some Wtf proteins have expression or localization patterns that are distinct from the poison and antidote proteins encoded by drivers and suppressors, suggesting some wtf genes may have non-meiotic drive functions. Overall, this work expands our understanding of the wtf gene family and the burden selfish driver genes impose on S. pombe.
减数分裂驱动因子是自私的等位基因,它们可以迫使杂合体产生的超过 50%的可育配子传递下去。减数分裂驱动因子已知会导致多种真核生物不孕,并预测会影响基因组结构和减数分裂的进化。裂殖酵母的 wtf 基因家族包括减数分裂驱动因子和驱动抑制因子,因此提供了一个可行的模式生物来研究驱动系统。目前,只有少数几个 wtf 基因的功能得到了表征,而这些基因仅部分反映了 wtf 基因家族的多样性。在这项工作中,我们对 22 个额外的 wtf 基因进行了减数分裂驱动表型的功能测试。我们发现了 8 个新的驱动因子,它们与之前表征的驱动因子具有 30-90%的氨基酸同一性。尽管这些基因之间存在巨大的差异,但它们在杂合子时通常能驱动超过 85%的配子。我们还发现了 3 个 wtf 基因可以抑制其他 wtf 驱动因子,包括 2 个也可以作为自主驱动因子的基因。此外,我们发现 wtf 基因不是染色体 1 上一个弱(64%等位基因传递)减数分裂驱动因子的基础。最后,我们发现一些 Wtf 蛋白的表达或定位模式与驱动因子和抑制因子编码的毒素和解毒剂蛋白不同,这表明一些 wtf 基因可能具有非减数分裂驱动功能。总的来说,这项工作扩展了我们对 wtf 基因家族的理解,以及自私驱动基因对裂殖酵母的负担。