Publication Date:
2014-05-16
Description:
The silkworm Bombyx mori uses a WZ sex determination system that is analogous to the one found in birds and some reptiles. In this system, males have two Z sex chromosomes, whereas females have Z and W sex chromosomes. The silkworm W chromosome has a dominant role in female determination, suggesting the existence of a dominant feminizing gene in this chromosome. However, the W chromosome is almost fully occupied by transposable element sequences, and no functional protein-coding gene has been identified so far. Female-enriched PIWI-interacting RNAs (piRNAs) are the only known transcripts that are produced from the sex-determining region of the W chromosome, but the function(s) of these piRNAs are unknown. Here we show that a W-chromosome-derived, female-specific piRNA is the feminizing factor of B. mori. This piRNA is produced from a piRNA precursor which we named Fem. Fem sequences were arranged in tandem in the sex-determining region of the W chromosome. Inhibition of Fem-derived piRNA-mediated signalling in female embryos led to the production of the male-specific splice variants of B. mori doublesex (Bmdsx), a gene which acts at the downstream end of the sex differentiation cascade. A target gene of Fem-derived piRNA was identified on the Z chromosome of B. mori. This gene, which we named Masc, encoded a CCCH-type zinc finger protein. We show that the silencing of Masc messenger RNA by Fem piRNA is required for the production of female-specific isoforms of Bmdsx in female embryos, and that Masc protein controls both dosage compensation and masculinization in male embryos. Our study characterizes a single small RNA that is responsible for primary sex determination in the WZ sex determination system.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kiuchi, Takashi -- Koga, Hikaru -- Kawamoto, Munetaka -- Shoji, Keisuke -- Sakai, Hiroki -- Arai, Yuji -- Ishihara, Genki -- Kawaoka, Shinpei -- Sugano, Sumio -- Shimada, Toru -- Suzuki, Yutaka -- Suzuki, Masataka G -- Katsuma, Susumu -- England -- Nature. 2014 May 29;509(7502):633-6. doi: 10.1038/nature13315. Epub 2014 May 14.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan. ; 1] Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan [2]. ; Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan. ; Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24828047" target="_blank"〉PubMed〈/a〉
Keywords:
Alternative Splicing/genetics
;
Animals
;
Base Sequence
;
Bombyx/embryology/*genetics
;
Dosage Compensation, Genetic
;
Female
;
Male
;
Molecular Sequence Data
;
RNA, Small Interfering/*genetics
;
*Sex Characteristics
;
Sex Chromosomes/genetics
;
Sex Determination Processes/*genetics
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
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