Meiotic drivers are selfish elements that bias their own transmission into more than half of the viable progeny produced by a driver+/driver− heterozygote. Meiotic drivers are thought to exist for relatively short evolutionary timespans because a driver gene or gene family is often found in a single species or in a group of very closely related species. Additionally, drivers are generally considered doomed to extinction when they spread to fixation or when suppressors arise. In this study, we examine the evolutionary history of the wtf meiotic drivers first discovered in the fission yeast Schizosaccharomyces pombe. We identify homologous genes in three other fission yeast species, S. octosporus, S. osmophilus, and S. cryophilus, which are estimated to have diverged over 100 million years ago from the S. pombe lineage. Synteny evidence supports that wtf genes were present in the common ancestor of these four species. Moreover, the ancestral genes were likely drivers as wtf genes in S. octosporus cause meiotic drive. Our findings indicate that meiotic drive systems can be maintained for long evolutionary timespans.

Meiotic drivers bias gametogenesis to ensure their transmission into more than half the offspring of a heterozygote. In Schizosaccharomyces pombe, wtf meiotic drivers destroy the meiotic products (spores) that do not inherit the driver from a heterozygote, thereby reducing fertility. wtf drivers encode both a Wtf poison protein and a Wtf antidote protein using alternative transcriptional start sites. Here, we analyze how the expression and localization of the Wtf proteins are regulated to achieve drive. We show that transcriptional timing and selective protein exclusion from developing spores ensure that all spores are exposed to Wtf4 poison, but only the spores that inherit wtf4 receive a dose of Wtf4 antidote sufficient for survival. In addition, we show that the Mei4 transcription factor, a master regulator of meiosis, controls the expression of the wtf4 poison transcript. This dual transcriptional regulation, which includes the use of a critical meiotic transcription factor, likely complicates the universal suppression of wtf genes without concomitantly disrupting spore viability. We propose that these features contribute to the evolutionary success of the wtf drivers.

Meiotic drivers bias gametogenesis to ensure their transmission into more than half the offspring of a heterozygote. In Schizosaccharomyces pombe, wtf meiotic drivers destroy the meiotic products (spores) that do not inherit the driver from a heterozygote, thereby reducing fertility. wtf drivers encode both a Wtfpoison protein and a Wtfantidote protein using alternative transcriptional start sites. Here, we analyze how the expression and localization of the Wtf proteins are regulated to achieve drive. We show that transcriptional timing and selective protein exclusion from developing spores ensure that all spores are exposed to Wtf4poison, but only the spores that inherit wtf4 receive a dose of Wtf4antidote sufficient for survival. In addition, we show that the Mei4 transcription factor, a master regulator of meiosis, controls the expression of the wtf4poison transcript. This transcriptional regulation, which includes the use of a critical meiotic transcription factor, likely complicates the universal suppression of wtf genes without concomitantly disrupting spore viability. We propose that these features contribute to the evolutionary success of the wtf drivers.

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Meiotic drivers are selfish elements that bias their own transmission into more than half of the viable progeny produced by a driver+/driver− heterozygote. Meiotic drivers are thought to exist for relatively short evolutionary timespans because a driver gene or gene family is often found in a single species or in a group of very closely related species. Additionally, drivers are generally considered doomed to extinction when they spread to fixation or when suppressors arise. In this study, we examine the evolutionary history of the wtf meiotic drivers first discovered in the fission yeast Schizosaccharomyces pombe. We identify homologous genes in three other fission yeast species S. octosporus, S. osmophilus, and S. cryophilus, which are estimated to have diverged over 100 million years ago from the S. pombe lineage. Synteny evidence supports that wtf genes were present in the common ancestor of these four species. Moreover, the ancestral genes were likely drivers as wtf genes in S. octosporus cause meiotic drive. Our findings indicate that active meiotic drive systems can be maintained for long evolutionary timespans.

critiques compared with some other fi elds where you hear from colleagues about which papers or authors are not trustworthy but cannot fi nd published critiques. Post-publication peer review in the form of social media posts is useful if the identifi ed issues are relatively simple and obvious. Because blog and Twitter posts tend to be brief and informal, they can be imprecise, unbalanced, and even confusing. Peer review of critiques (typically handled by the journal that published the paper being critiqued) can help to ensure that they are written clearly, fairly, and in a measured tone, which helps readers to understand the issue. I am disappointed, however, that many journals in biology do not welcome critiques of their papers. Do you support open-access publication?Defi nitely as a reader but not as an author. For a non-openaccess publication, the page and color charge that I pay is probably around 1,000 USD. The open-access fee is several times higher and in some cases exceeds 5,000 USD per paper. Unfortunately, grants have not kept pace, so open-access publication decreases research dollars. What do you think is the biggest current challenge facing the scientifi c community?The biggest challenge is always the ability to attract and retain talent. With the deterioration of funding and the scientifi c ignorance of some of our elected leaders, both issues of which refl ect the public opinion about science to some degree, the outlook is not bright. In the long run, however, science must attract talent by its own merit. If you had not made it as a scientist, what would you have become?As a teenager, I liked writing and wrote a lot. I have not written anything serious in Chinese for over 25 years but still read a great amount of Chinese history, politics, and literature. I believe that I could be an essayist if not a scientist.