title: RNAi-mediated knockdown of transformer-2 in the predatory mite Metaseiulus occidentalis via oral delivery of double-stranded RNA.
abstract: Little is known about the process of sex determination at the molecular level in Metaseiulus occidentalis, a parahaploid species and natural enemy of phytophagous pest mites. Detailed knowledge of the sex-determination pathway could allow genetic manipulation of M. occidentalis to produce more female offspring, which could improve its effectiveness as a biological control agent. RNA interference is useful for assessing the function of putative sex-determination genes by reducing or eliminating gene expression. In many insect species the transformer-2 (tra-2) gene is an upstream regulatory element in the sex-determination cascade, and knockdown of tra-2 expression can alter the sex ratio. We assessed whether oral delivery of tra-2 double-stranded RNA to M. occidentalis virgin females would affect the sex of her progeny. Females that ingested tra-2 dsRNA produced significantly fewer eggs compared to control females suggesting that tra-2 is somehow involved in reproduction by females. However, the sex ratio of the few progeny that were laid was not altered, so it is unclear whether tra-2 is involved in sex determination. This is an initial step towards elucidating the molecular components of sex determination in M. occidentalis.
authors.affiliation: Department of Entomology and Nematology, University of Florida, Gainesville, FL, USA, apomerantz@ufl.edu.
authors.forename: Aaron F
authors.initials: AF
authors.lastname: Pomerantz
authors.forename: Marjorie A
authors.initials: MA
authors.lastname: Hoy
mesh_terms: D000818:Animals; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D055785:Gene Knockdown Techniques / Q000379:methods*; D008297:Male; D008925:Mites / Q000235:genetics / Q000502:physiology*; D034622:RNA Interference; D012330:RNA, Double-Stranded / Q000008:administration & dosage; D012098:Reproduction; D012261:Ribonucleoproteins / Q000235:genetics / Q000378:metabolism*; D019849:Sex Determination Processes / Q000235:genetics; D012744:Sex Ratio
chemical_list: D029721:Drosophila Proteins; D012330:RNA, Double-Stranded; D012261:Ribonucleoproteins; C066174:tra2 protein, Drosophila