Chasnov J R, So W K, Chan C M, Chow K L
Department of Mathematics and Biology, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
Proc Natl Acad Sci U S A. 2007 Apr 17;104(16):6730-5. doi: 10.1073/pnas.0608050104. Epub 2007 Apr 6.
Four species in the ELEGANS group of subgenus the Caenorhabditis are distinguished by two very different mating systems: androdioecy in C. elegans and Caenorhabditis briggsae with males and self-fertilizing hermaphrodites and dioecy in Caenorhabditis remanei and Caenorhabditis sp. strain CB5161 with males and females. Using chemotaxis assays, we demonstrate that females secrete a potent sex pheromone that attracts males from a distance, whereas hermaphrodites do not. The female sex pheromone is not species-specific, with males of all four species attracted to both the C. remanei and Caenorhabditis sp. female sex pheromones. The pheromone is, however, sex-specific, with only females secreting the pheromone and attracting only males. Furthermore, the sex pheromone is stage-specific, with female secretion and male detection of the pheromone beginning near adulthood. Females lose their attractiveness immediately after mating but regain it several hours after mating ceases. Finally, the female somatic gonad is required for sex-pheromone production, and the male-specific cephalic neurons (CEM) are required for male response.
秀丽隐杆线虫和布氏秀丽隐杆线虫为雄雄同体，具有雄性和能自体受精的雌雄同体；雷氏秀丽隐杆线虫和秀丽隐杆线虫品系CB5161为雌雄异体，具有雄性和雌性。通过趋化性测定，我们证明雌性分泌一种强效性信息素，能在一定距离外吸引雄性，而雌雄同体则不会。雌性性信息素并非物种特异性的，这四个物种的雄性都被雷氏秀丽隐杆线虫和秀丽隐杆线虫品系的雌性性信息素所吸引。然而，性信息素具有性别特异性，只有雌性分泌该信息素且只吸引雄性。此外，性信息素具有阶段特异性，雌性分泌和雄性检测到该信息素始于成年期附近。雌性在交配后立即失去吸引力，但在交配停止数小时后恢复。最后，雌性体细胞性腺是产生性信息素所必需的，而雄性特异性头部神经元（CEM）是雄性做出反应所必需的。
