Study of sex determination mechanisms in Wasmannia auropunctata

Research Project

Project/Area Number	24770034
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Multi-year Fund
Research Field	Ecology/Environment
Research Institution	Okinawa Institute of Science and Technology Graduate University
Principal Investigator	MIKHEYEV Alexander 沖縄科学技術大学院大学, その他の研究科, 准教授 (90601162)
Project Period (FY)	2012-04-01 – 2015-03-31
Project Status	Completed (Fiscal Year 2014)
Budget Amount *help	¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000) Fiscal Year 2013: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000) Fiscal Year 2012: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Keywords	genomics / sex determination / reproduction / social insects / ants / RAD-tag
Outline of Final Research Achievements	Recent, though controversial, comparative genomic studies proposed that a core pathway underlies complementary sex determination (CSD) in many, if not all, hymenopteran insects. First characterized in honey bees, it involves the joint action of tandemly arranged homologs of the fruit fly transformer gene. We used an experimental cross to test whether the sex determination mechanism is conserved in the ant Vollenhovia emeryi. Two QTLs on separate linkage groups (CsdQTL1 and CsdQTL2) jointly explained 98.0% of the phenotypic variance. CsdQTL1 included two tandem transformer homologs, with one under diversifying selection, as in the honey bee, suggesting a mechanism shared for over 100 million years. CsdQTL2 had no homology to CsdQTL1 and included a region more than 250kb. As multi-locus CSD can collapse to a single gene, alternate loci such as CsdQTL2, can provide intermediates to other sex determination pathways. Multi-locus CSD may explain the diversity of sex determination pathways.