Karsi A, Li P, Dunham R A, Liu Z J
Department of Fisheries and Allied Aquacultures, Auburn University, Alabama 36849, USA.
J Mol Endocrinol. 1998 Oct;21(2):121-9. doi: 10.1677/jme.0.0210121.
Expressed sequence tag (EST) analysis was adopted to address physiological changes after injection of carp pituitary extract for induction of ovulation. ESTs were analyzed from cDNA libraries constructed from mRNA isolated from channel catfish (Ictalurus punctatus) pituitaries before and after induction of ovulation by injection of carp pituitary extract. One hundred randomly picked clones were analyzed. Of the sequences generated, a large percentage (59%) of ESTs were identified as known genes by identity comparisons. These 59 clones of known gene products represent transcriptional products of 30 genes. The 41 clones of unknown gene products represent 33 genes. Expression of gonadotropin (GtH) alpha-subunit (149%) and prolactin (176%) was slightly enhanced as a result of induced ovulation. Large increases in frequencies of several peptide hormones were observed as a result of induced ovulation: GtH beta-I, 486%; GtH beta-II, 933%; growth hormone, 393%; proopiomelanocortin (POMC), 345%. POMC represented about 21% of all transcriptional activity in the pituitaries after induced ovulation. This is the first study addressing physiological changes after injection of carp pituitary extract, a procedure widely used in catfish hatcheries.
采用表达序列标签（EST）分析方法来研究注射鲤鱼垂体提取物诱导排卵后的生理变化。EST分析取自鲶鱼（斑点叉尾鮰）垂体，在注射鲤鱼垂体提取物诱导排卵前后，从分离的mRNA构建的cDNA文库中进行。分析了100个随机挑选的克隆。在产生的序列中，通过同一性比较，很大比例（59%）的EST被鉴定为已知基因。这59个已知基因产物的克隆代表了30个基因的转录产物。41个未知基因产物的克隆代表了33个基因。诱导排卵后，促性腺激素（GtH）α亚基（149%）和催乳素（176%）的表达略有增强。诱导排卵后，观察到几种肽类激素的频率大幅增加：GtHβ-I，486%；GtHβ-II，933%；生长激素，393%；阿黑皮素原（POMC），345%。诱导排卵后，POMC约占垂体所有转录活性的21%。这是第一项研究注射鲤鱼垂体提取物后的生理变化的研究，该方法在鲶鱼孵化场广泛使用。
