Evolution of piRNA clusters in the Drosophila melanogaster ovary
To investigate piC origin and evolution, we used a population genomics to compare piC activity and sequence composition across 8 geographically distant strains of D. melanogaster with high quality long-read genome assemblies. To this end, we perform de novo annotations of ovary piCs for two replicate small RNA libraries independently in each strain. Each replicate of small RNA library was constructed from NEB Next small RNA library kit. Small RNAs were isolated by Urea-PAGE from 10ug of total RNA extracted from 20-25 pairs of ovaries dissected from 4-6 day old yeast-fed female flies.