title: Insights into eyestalk ablation mechanism to induce ovarian maturation in the black tiger shrimp.
abstract: Eyestalk ablation is commonly practiced in crustacean to induce ovarian maturation in captivity. The molecular mechanism of the ablation has not been well understood, preventing a search for alternative measures to induce ovarian maturation in aquaculture. This is the first study to employ cDNA microarray to examine effects of eyestalk ablation at the transcriptomic level and pathway mapping analysis to identify potentially affected biological pathways in the black tiger shrimp (Penaeus monodon). Microarray analysis comparing between gene expression levels of ovaries from eyestalk-intact and eyestalk-ablated brooders revealed 682 differentially expressed transcripts. Based on Hierarchical clustering of gene expression patterns, Gene Ontology annotation, and relevant functions of these differentially expressed genes, several gene groups were further examined by pathway mapping analysis. Reverse-transcriptase quantitative PCR analysis for some representative transcripts confirmed microarray data. Known reproductive genes involved in vitellogenesis were dramatically increased during the ablation. Besides these transcripts expected to be induced by the ablation, transcripts whose functions involved in electron transfer mechanism, immune responses and calcium signal transduction were significantly altered following the ablation. Pathway mapping analysis revealed that the activation of gonadotropin-releasing hormone signaling, calcium signaling, and progesterone-mediated oocyte maturation pathways were putatively crucial to ovarian maturation induced by the ablation. These findings shed light on several possible molecular mechanisms of the eyestalk ablation effect and allow more focused investigation for an ultimate goal of finding alternative methods to replace the undesirable practice of the eyestalk ablation in the future.
authors.affiliation: National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, Klong Luang, Pathumthani, Thailand.
authors.forename: Umaporn
authors.initials: U
authors.lastname: Uawisetwathana
authors.forename: Rungnapa
authors.initials: R
authors.lastname: Leelatanawit
authors.forename: Amornpan
authors.initials: A
authors.lastname: Klanchui
authors.forename: Juthatip
authors.initials: J
authors.lastname: Prommoon
authors.forename: Sirawut
authors.initials: S
authors.lastname: Klinbunga
authors.forename: Nitsara
authors.initials: N
authors.lastname: Karoonuthaisiri
mesh_terms: D000818:Animals; D004702:Endocrine Glands / Q000601:surgery*; D005260:Female; D020869:Gene Expression Profiling / Q000379:methods*; D007987:Gonadotropin-Releasing Hormone / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D010053:Ovary / Q000254:growth & development* / Q000378:metabolism; D033561:Penaeidae / Q000235:genetics* / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology
chemical_list: D007987:Gonadotropin-Releasing Hormone