Int J Biol Sci 2011; 7(4):469-475. doi:10.7150/ijbs.7.469 This issue Cite
1. Department of Biological Sciences, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260;
2. Key Laboratory of Freshwater Ecology, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, No. 8, 1st Wudayuan Road, Donghu Hi-Tech Development Zone, Wuhan, Hubei 430223, China.
#Present address: Department of Orthopaedic Surgery, National University of Singapore; DSO Kent Ridge 27, Medical Drive Singapore 119074
Sperm nuclear transfer or intracytoplasmic sperm injection (ICSI) is a powerful assisted reproductive technology (ART) for treating human male infertility. Controversial reports of increased birth defects have raised concerns about the ART's safety. The cause for birth defects, however, has remained elusive for analysis in human because of the sample size, male infertility genetics, physiological heterogeneity and associated procedures such as embryo manipulations. Animal models are required to evaluate factors leading to the increased birth defects. Here we report the establishment of medakafish model for ICSI and transgenic production. This small laboratory fish has high fecundity and easy embryology. We show that ICSI produced a 5% high percentage of fertile animals that exhibited both paternal and maternal contribution as evidenced by the pigmentation marker. Furthermore, when sperm were pre-incubated with a plasmid ubiquitously expressing RFP and subjected to ICSI, 50% of sperm nuclear transplants showed germline transmission. We conclude that medaka is an excellent model for ICSI to evaluate birth defects and that sperm nuclear transfer can mediate stable gene transfer at high efficiency. Although more demanding for experimentation, sperm-mediated transgenesis should be particularly applicable for aquaculture species with a lengthy generation time and/or a large adult body size.
Keywords: medaka, nuclear transfer, sperm, gene transfer, transgenesis