Project description: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 genome uniquely and are thought to regulate genes required for male fertility. In human males, the developmental classes, precise genomic origins, and transcriptional regulation of post-natal piRNAs remain undefined. Here, we demarcate the genes and transcripts that produce post-natal piRNAs in human juvenile and adult testes. As in mouse, A‑MYB in humans drives transcription of both pachytene piRNA precursor transcripts and the mRNAs 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 fewer selective constraints. We speculate that pachytene piRNA diversity may provide a hitherto unrecognized driver of reproductive isolation.

2019-12-23 | GSE135791 | GEO

Management of local stressors can improve the resilience of marine canopy algae to global stressors.

Project description: Not available

| S-EPMC4373769 | biostudies-literature

Adverse childhood experiences: Mechanisms of risk and resilience in a longitudinal urban cohort.

Project description: Not available

| S-EPMC7190431 | biostudies-literature

Local Stressors, Resilience, and Shifting Baselines on Coral Reefs.

Project description: Not available

| S-EPMC5130202 | biostudies-literature