Determination in oocytes of the reproductive modes for the brine shrimp Artemia parthenogenetica. Issue 1 (4th October 2010)

• Record Type: Journal Article
• Authors: Dai, Zhong-Min; Li, Ran; Dai, Li; Yang, Jin-Shu; Chen, Su; Zeng, Qing-Guo; Yang, Fan; Yang, Wei-Jun
• Is Part Of: Bioscience reports. Volume 31:Issue 1(2011)
• Page Start: 17
• Page End: 30
• Publication Date: 2010-10-04
• Subjects: Artemia -- diapause -- duplex-specific nuclease -- oocyte -- subtractive hybridization; Molecular biology -- Periodicals; Cytology -- Periodicals; 572.8
• DOI: 10.1042/BSR20090141
• Languages: English
• ISSNs: 0144-8463

Abstract

Abstract : The brine shrimp, Artemia, reproduces either oviparously, producing encysted embryos (diapause cysts), or ovoviviparously, producing free-swimming nauplii. Environmental factors, such as photoperiod, have been applied to control the reproduction mode of Artemia, but when the determination of a reproductive mode occurs remains unknown. We analysed the differential gene expression between oocytes from oviparous and ovoviviparous Artemia reared under different photoperiods. A total of 692 qualified cDNA clones were obtained by subtractive hybridization, 327 of which matched GenBank® Nucleotide Sequence Database entries. Gene expressions of 44 cDNAs (representing 56 clones) were analysed in oocytes using real-time PCR. Among these genes, 11 (21 clones) were significantly ( P <0.05) up-regulated and 7 (9 clones) down-regulated in Artemia oocytes that subsequently enter diapause. Remarkably, known diapause-related proteins such as ArHsp22 ( Artemia heat-shock protein 22) and chitin-binding proteins are found to be already differentially expressed. Furthermore, RNAi (RNA interference) knockdown of a differentially expressed gene, polo-like kinase 1, in oocyte of ovoviviparous Artemia led to the production of white embryos rather than free-swimming nauplii. In summary, our results provide evidence at the molecular level that the reproductive mode of Artemia is already determined at the oocyte stage of their life cycle.