RT Journal Article
SR Electronic
T1 Changes in brain microRNAs are associated with social evolution in bees
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 730317
DO 10.1101/730317
A1 Karen M. Kapheim
A1 Beryl M. Jones
A1 Eirik Søvik
A1 Eckart Stolle
A1 Robert M. Waterhouse
A1 Guy Bloch
A1 Yehuda Ben-Shahar
YR 2019
UL http://biorxiv.org/content/early/2019/11/25/730317.abstract
AB Evolutionary transitions to a social lifestyle in insects are associated with lineage-specific changes in gene expression, but the key nodes that drive these regulatory changes are largely unknown. We tested the hypothesis that changes in gene regulation associated with social evolution are facilitated by lineage-specific function of microRNAs (miRNAs). Genome scans across 12 bee species showed that miRNA copy-number is mostly conserved and not associated with sociality. However, deep sequencing of small RNAs in six bee species revealed a substantial proportion (20-35%) of detected miRNAs had lineage-specific expression in the brain, 24-72% of which did not have homologs in other species. Lineage-specific miRNAs disproportionately target lineage-specific genes, and have lower expression levels than shared miRNAs. The predicted targets of lineage-specific miRNAs are enriched for genes related to social behavior in social species, but they are not enriched for genes under positive selection. Together, these results suggest that novel miRNAs may contribute to lineage-specific patterns of social evolution. Our analyses also support the hypothesis that many new miRNAs are purged by selection due to deleterious effects on mRNA targets, and suggest genome structure is not as influential in regulating bee miRNA evolution as has been shown for mammalian miRNAs.