查看文章

The present study was undertaken to determine whether T₃, estrogen, and 11-ketotestosterone could alter a specific population of GnRH-containing neurons, as indicated by a change in messenger RNA (mRNA) levels in sexually immature male tilapia, Oreochromis niloticus. Two weeks after castration, fish were assigned to four treatment groups. One group served as the control (sesame oil); a single ip injection of (T₃; 5 μg/g), estradiol benzoate (EB; 5 μg/g), or 11-ketotestosterone (KT; 5 μg/g) was administered to the remaining three groups. Twenty-four hours after the injection, brains were collected and processed for in situ hybridization histochemistry using ³⁵S-labeled 30-mer antisense oligonucleotide probes complementary to the GnRH-coding region of chicken II, salmon, and seabream GnRH. Computerized image analysis was performed to quantify mRNA concentrations, neuronal numbers, and …