title: Expression profile of the sex determination gene doublesex in a gynandromorph of bumblebee, Bombus ignitus.
abstract: Gynandromorphy that has both male and female features is known in many insect orders, including Hymenoptera. In most cases, however, only external morphology and behavioral aspects have been studied. We found a gynandromorph of bumblebee, Bombus ignitus, that showed almost bilateral distribution of external sexual traits, with male characters observed on the left side and female characters on the right side. This individual never exhibited sexual behavior toward new queens. The dissection of the head part showed that it had bilaterally dimorphic labial glands, only the left of which was well developed and synthesized male-specific pheromone components. In contrast, the gynandromorph possessed an ovipositor and a pair of ovaries in the abdominal part, suggesting that it had a uniformly female reproductive system. Furthermore, we characterized several internal organs of the gynandromorph by a molecular biological approach. The expression analyses of a sex determination gene, doublesex, in the brain, the fat bodies, the hindgut, and the ovaries of the gynandromorph revealed a male-type expression pattern exclusively in the left brain hemisphere and consistent female-type expression in other tissues. These findings clearly indicate the sexual discordance between external traits and internal organs in the gynandromorph. The results of genetic analyses using microsatellite markers suggested that this individual consisted of both genetically male- and female-type tissues.
authors: Laboratory of Applied Entomology and Zoology, Graduate School of Agriculture, Tamagawa University, 6-1-1, Tamagawagakuen, Machida, Tokyo, 194-8610, Japan. ugajin@agr.tamagawa.ac.jp.
authors: Atsushi
authors: A
authors: Ugajin
authors: Laboratory of Applied Entomology and Zoology, Graduate School of Agriculture, Tamagawa University, 6-1-1, Tamagawagakuen, Machida, Tokyo, 194-8610, Japan.
authors: Koshiro
authors: K
authors: Matsuo
authors: Honeybee Science Research Center, Tamagawa University, 6-1-1, Tamagawagakuen, Machida, Tokyo, 194-8610, Japan.
authors: Ryohei
authors: R
authors: Kubo
authors: Honeybee Science Research Center, Tamagawa University, 6-1-1, Tamagawagakuen, Machida, Tokyo, 194-8610, Japan.
authors: Tetsuhiko
authors: T
authors: Sasaki
authors: Laboratory of Applied Entomology and Zoology, Graduate School of Agriculture, Tamagawa University, 6-1-1, Tamagawagakuen, Machida, Tokyo, 194-8610, Japan.
authors: Masato
authors: M
authors: Ono
mesh_terms: D000818:Animals; D001516:Bees / Q000033:anatomy & histology / Q000235:genetics / Q000502:physiology*; D001522:Behavior, Animal; D005260:Female; D005786:Gene Expression Regulation; D017344:Genes, Insect / Q000235:genetics*; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D019849:Sex Determination Processes / Q000235:genetics*; D059467:Transcriptome
keywords: Bumblebee; Gynandromorph; Haplodiploidy; doublesex