The silkworm W chromosome is a source of female-enriched piRNAs.
In the silkworm, Bombyx mori, the W chromosome plays a dominant role in female determination. However, neither protein-coding genes nor transcripts have so far been isolated from the W chromosome. Instead, a large amount of functional transposable elements and their remnants are accumulated on the W chromosome. PIWI-interacting RNAs (piRNAs) are 23-30-nt-long small RNAs that potentially act as sequence-specific guides for PIWI proteins to silence transposon activity in animal gonads. In this study, by comparing ovary- and testis-derived piRNAs, we identified numerous female-enriched piRNAs. Our data indicated that female-enriched piRNAs are derived from the W chromosome. Moreover, comparative analyses on piRNA profiles from a series of W chromosome mutant strains revealed a striking enrichment of a specific set of transposon-derived piRNAs in the putative sex-determining region. Collectively, we revealed the nature of the silkworm W chromosome as a source of piRNAs.
Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.
Shinpei
S
Kawaoka
Koji
K
Kadota
Yuji
Y
Arai
Yutaka
Y
Suzuki
Tsuguru
T
Fujii
Hiroaki
H
Abe
Yuji
Y
Yasukochi
Kazuei
K
Mita
Sumio
S
Sugano
Kentaro
K
Shimizu
Yukihide
Y
Tomari
Toru
T
Shimada
Susumu
S
Katsuma
D000818:Animals; D012831:Bombyx / Q000235:genetics* / Q000378:metabolism; D059006:Chromosomes, Insect / Q000235:genetics*; D004251:DNA Transposable Elements; D005260:Female; D005786:Gene Expression Regulation; D006066:Gonads / Q000378:metabolism; D008297:Male; D008957:Models, Genetic; D034741:RNA, Small Interfering / Q000235:genetics* / Q000378:metabolism; D012727:Sex Characteristics; D012730:Sex Chromosomes / Q000235:genetics*; D019849:Sex Determination Processes
D004251:DNA Transposable Elements; D034741:RNA, Small Interfering