Evolutionarily conserved pachytene piRNA loci are highly divergent among modern humans

• Published in: Nature ecology & evolution Vol. 4; no. 1; pp. 156 - 168
• Main Authors: Özata, Deniz M., Yu, Tianxiong, Mou, Haiwei, Gainetdinov, Ildar, Colpan, Cansu, Cecchini, Katharine, Kaymaz, Yasin, Wu, Pei-Hsuan, Fan, Kaili, Kucukural, Alper, Weng, Zhiping, Zamore, Phillip D.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.01.2020; Nature Publishing Group
• Subjects: 38/91; 45/15; 45/23; 45/90; 45/91; 631/136; 631/181; 631/208; 64/60; Adolescent; Animals; Biological and Physical Anthropology; Biological evolution; Biomedical and Life Sciences; Divergence; Ecology; Evolutionary Biology; Evolutionary conservation; Evolutionary genetics; Female; Fertility; Fetuses; Gene expression; Gene Expression Regulation; Gene mapping; Gene regulation; Genes; Genome; Genomes; Hominids; Humans; Life Sciences; Loci; Male; Mammals; Mapping; Mice; Pachytene; Paleontology; Pregnancy; Reproductive isolation; RNA, Messenger; RNA, Small Interfering; Synteny; Testes; Testis; Transcription; Transposons; Zoology
• ISSN: 2397-334X; 2397-334X
• DOI: 10.1038/s41559-019-1065-1

In the fetal mouse testis, PIWI-interacting RNAs (piRNAs) guide PIWI proteins to silence transposons but, after birth, most post-pubertal pachytene piRNAs map to the genome uniquely and are thought to regulate genes required for male fertility. In the human male, the developmental classes, precise genomic origins and transcriptional regulation of postnatal piRNAs remain undefined. Here, we demarcate the genes and transcripts that produce postnatal piRNAs in human juvenile and adult testes. As in the mouse, human A-MYB drives transcription of both pachytene piRNA precursor transcripts and messenger RNAs encoding piRNA biogenesis factors. Although human piRNA genes are syntenic to those in other placental mammals, their sequences are poorly conserved. In fact, pachytene piRNA loci are rapidly diverging even among modern humans. Our findings suggest that, during mammalian evolution, pachytene piRNA genes are under few selective constraints. We speculate that pachytene piRNA diversity may provide a hitherto unrecognized driver of reproductive isolation. By mapping piRNA genes in juvenile and adult human testes, the authors show that although synteny is conserved with other mammals, sequences are diverging rapidly even among modern humans.