title: Influence of temperature and gonadal steroids on the ontogenetic expression of brain serotonin 1A and 1D receptors during the critical period of sexual differentiation in tilapia, Oreochromis mossambicus.
abstract: cDNA sequences of serotonin (5-hydroxytryptamine, 5-HT) 1A and 1D receptors were cloned from the tilapia, Oreochromis mossambicus, brain. The influence of both gonadal steroids and temperature on the ontogenetic expression of brain 5-HT1A and 5-HT1D receptors from days 5 to 15 post-hatch, a critical period of sexual differentiation, was investigated using quantitative real-time reverse transcription-polymerase chain reaction. Neither estrogen nor methyltestosterone had an effect on the ontogenetic expression of 5-HT1A or 5-HT1D receptors. Between days 5 and 10 post-hatch, a critical period for low-temperature-induced feminization, we found no significant difference in the ontogenetic expression of 5-HT1A between exposure to low and elevated temperature. A similar result was found for 5-HT1D. Between days 10 and 15 post-hatch, a critical period for elevated-temperature-induced masculinization, the ontogenetic expression of neither brain 5-HT1A nor 5-HT1D was altered by exposure to elevated temperature. These results suggest that neither brain 5-HT1A nor 5-HT1D plays a critical role in either gonadal steroid- or temperature-induced sexual differentiation.
authors.affiliation: National Museum of Marine Biology and Aquarium, 2 Houwan Road, Checheng, Pingtung 944, Taiwan.
authors.forename: Li-Hsueh
authors.initials: LH
authors.lastname: Wang
authors.forename: Ching-Lin
authors.initials: CL
authors.lastname: Tsai
mesh_terms: D000375:Aging; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D005260:Female; D012739:Gonadal Steroid Hormones / Q000494:pharmacology*; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000378:metabolism; D044282:Receptor, Serotonin, 5-HT1A / Q000235:genetics* / Q000378:metabolism; D044346:Receptor, Serotonin, 5-HT1D / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D012727:Sex Characteristics; D012733:Sex Differentiation; D013696:Temperature; D017210:Tilapia / Q000378:metabolism*; D013997:Time Factors
chemical_list: D012739:Gonadal Steroid Hormones; D012333:RNA, Messenger; D044346:Receptor, Serotonin, 5-HT1D; D044282:Receptor, Serotonin, 5-HT1A