PDF(Pubmed)
Abstract：
Sexual maturation of Atlantic salmon males is marked by dramatic endocrine changes and rapid growth of the testes, resulting in an increase in the gonad somatic index (GSI). We examined the association of gonadal growth with serum sex steroids, as well as pituitary and testicular gene expression levels, which were assessed with a DNA oligonucleotide microarray. The testes transcriptome was stable in males with a GSI < 0.08% despite the large difference between the smallest and the largest gonads. Fish with a GSI ≥ 0.23% had 7-17 times higher serum levels of five male steroids and a 2-fold increase in progesterone, without a change in cortisol and related steroids. The pituitary transcriptome showed an upregulation of the hormone-coding genes that control reproduction and behavior, and structural rearrangement was indicated by the genes involved in synaptic transmission and the differentiation of neurons. The observed changes in the abundance of testicular transcripts were caused by the regulation of transcription and/or disproportional growth, with a greater increase in the germinative compartment. As these factors could not be separated, the transcriptome results are presented as higher or lower specific activities (HSA and LSA). LSA was observed in 4268 genes, including many genes involved in various immune responses and developmental processes. LSA also included genes with roles in female reproduction, germinal cell maintenance and gonad development, responses to endocrine and neural regulation, and the biosynthesis of sex steroids. Two functional groups prevailed among HSA: structure and activity of the cilia (95 genes) and meiosis (34 genes). The puberty of A. salmon testis is marked by the predominance of spermatogenesis, which displaces other processes; masculinization; and the weakening of external regulation. Results confirmed the known roles of many genes involved in reproduction and pointed to uncharacterized genes that deserve attention as possible regulators of sexual maturation.
摘要：
大西洋鲑鱼雄性的性成熟以剧烈的内分泌变化和睾丸的快速生长为标志，导致性腺体细胞指数（GSI）增加。我们检查了性腺生长与血清性类固醇的关系，以及垂体和睾丸基因表达水平，用DNA寡核苷酸微阵列评估。尽管最小和最大性腺之间存在很大差异，但GSI<0.08％的男性睾丸转录组稳定。GSI≥0.23％的鱼血清中5种雄性类固醇的水平高7-17倍，孕酮增加2倍，皮质醇和相关类固醇没有变化.垂体转录组显示控制生殖和行为的激素编码基因上调，参与突触传递和神经元分化的基因表明了结构重排。观察到的睾丸转录本丰度的变化是由转录调节和/或不成比例的生长引起的，发芽室的增加更大。由于这些因素不能分开，转录组结果表示为更高或更低的比活性(HSA和LSA)。在4268个基因中观察到LSA，包括许多参与各种免疫反应和发育过程的基因。LSA还包括在女性生殖中起作用的基因，生殖细胞维持和性腺发育，对内分泌和神经调节的反应，性类固醇的生物合成。HSA中普遍存在两个功能组：纤毛的结构和活性（95个基因）和减数分裂（34个基因）。A.鲑鱼睾丸的青春期以精子发生为主导，取代其他过程；男性化；以及外部监管的弱化。结果证实了许多参与生殖的基因的已知作用，并指出未表征的基因值得关注，可能是性成熟的调节因子。
