title: Defining global gene expression changes of the hypothalamic-pituitary-gonadal axis in female sGnRH-antisense transgenic common carp (Cyprinus carpio).
abstract: BACKGROUND
  The hypothalamic-pituitary-gonadal (HPG) axis is critical in the development and regulation of reproduction in fish. The inhibition of neuropeptide gonadotropin-releasing hormone (GnRH) expression may diminish or severely hamper gonadal development due to it being the key regulator of the axis, and then provide a model for the comprehensive study of the expression patterns of genes with respect to the fish reproductive system.
  
  
  RESULTS
  In a previous study we injected 342 fertilized eggs from the common carp (Cyprinus carpio) with a gene construct that expressed antisense sGnRH. Four years later, we found a total of 38 transgenic fish with abnormal or missing gonads. From this group we selected the 12 sterile females with abnormal ovaries in which we combined suppression subtractive hybridization (SSH) and cDNA microarray analysis to define changes in gene expression of the HPG axis in the present study. As a result, nine, 28, and 212 genes were separately identified as being differentially expressed in hypothalamus, pituitary, and ovary, of which 87 genes were novel. The number of down- and up-regulated genes was five and four (hypothalamus), 16 and 12 (pituitary), 119 and 93 (ovary), respectively. Functional analyses showed that these genes involved in several biological processes, such as biosynthesis, organogenesis, metabolism pathways, immune systems, transport links, and apoptosis. Within these categories, significant genes for neuropeptides, gonadotropins, metabolic, oogenesis and inflammatory factors were identified.
  
  
  CONCLUSIONS
  This study indicated the progressive scaling-up effect of hypothalamic sGnRH antisense on the pituitary and ovary receptors of female carp and provided comprehensive data with respect to global changes in gene expression throughout the HPG signaling pathway, contributing towards improving our understanding of the molecular mechanisms and regulative pathways in the reproductive system of teleost fish.
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Xu
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
authors.forename: Chengrong
authors.initials: C
authors.lastname: Zhong
authors.forename: Daji
authors.initials: D
authors.lastname: Luo
authors.forename: Shuangfei
authors.initials: S
authors.lastname: Li
authors.forename: Zuoyan
authors.initials: Z
authors.lastname: Zhu
authors.forename: Wei
authors.initials: W
authors.lastname: Hu
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D002347:Carps / Q000097:blood / Q000235:genetics* / Q000254:growth & development / Q000502:physiology; D005260:Female; D020869:Gene Expression Profiling; D007987:Gonadotropin-Releasing Hormone / Q000235:genetics*; D007030:Hypothalamo-Hypophyseal System / Q000378:metabolism*; D037101:Luteinizing Hormone, beta Subunit / Q000097:blood; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis; D010053:Ovary / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology; D016133:Polymerase Chain Reaction; D016372:RNA, Antisense / Q000235:genetics*; D015203:Reproducibility of Results; D012098:Reproduction
chemical_list: D037101:Luteinizing Hormone, beta Subunit; D016372:RNA, Antisense; D007987:Gonadotropin-Releasing Hormone