Identification of androgen-responsive genes in fish testis. Oncorhynchus mykiss

Sexual steroids play an important role in gonad maturation in all vertebrates. However, the molecular mechanisms regulating of spermatogenesis in seasonal breeding species are yet poorly understood. In this study we investigated the effects of testosterone and 11-ketotestosterone (11KT) - a teleost fish specific androgen - on testicular gene expression at the onset of puberty in the rainbow trout, Oncorhynchus mykiss. Overall design: Rainbow trout 13 months old were used. Immature males (spermatogonia only, stage I-II) were submitted to androgen supplementation by hormone implants for 7 or 14 days. This included : - untreated animal controls (N=14) - animals subjected to testosterone supplementation (0.1mg) for 7 days (N=5) - animals subjected to testosterone supplementation (0.2mg) for 7 days (N=4) - animals subjected to testosterone supplementation (0.2mg) for 14 days (N=5) - animals subjected to 11-ketotestosterone supplementation (0.25mg) for 7 days (N=7). Individual testes were recovered for microarray experiments and histological analyses. Circulating levels of corresponding androgens were also determined.

性甾体（sexual steroids）在所有脊椎动物的性腺成熟过程中具有关键调控作用。然而，季节性繁殖物种的精子发生调控分子机制仍不甚明晰。
本研究以虹鳟（Oncorhynchus mykiss）为实验材料，探究了睾酮（testosterone）与硬骨鱼特异性雄激素11-酮睾酮（11-ketotestosterone，11KT）在其青春期启动阶段对睾丸基因表达的调控效应。
实验设计概况：
本实验选用13月龄的虹鳟，选取仅存在精原细胞的Ⅰ-Ⅱ期未成熟雄鱼，通过激素埋植法施加雄激素处理，处理时长分为7天与14天两种。实验分组如下：
- 空白对照组（未进行任何处理，N=14）
- 0.1mg睾酮处理组（处理7天，N=5）
- 0.2mg睾酮处理组（处理7天，N=4）
- 0.2mg睾酮处理组（处理14天，N=5）
- 0.25mg 11-酮睾酮处理组（处理7天，N=7）
采集每条个体的睾丸组织，用于微阵列实验（microarray experiments）与组织学分析，同时检测各组血浆中对应雄激素的循环浓度。