Induction of meiotic gynogenesis in paddlefish (Polyodon spathula) and its confirmation using microsatellite markers

A protocol for gynogenesis of P. spathula was developed in order to produce inbred lines and to develop a technique to preserve the endangered Chinese paddlefish (Psephurus gladius). Diploid gynogenesis was induced in P. spathula using ultraviolet (UV)-irradiated Amur sturgeon (Acipenser schrenckii) sperm for 4.5-min, 5-min or 5.5-min and subsequent heat shock treatment. UV irradiation of sperm for 5 min at a UV intensity (254 nm) of 863 mu w cm(-2) was the optimum dose to achieve diploid gynogenesis on the basis of observations on hatching rate of eggs. Three microsatellite loci were used to monitor exclusive maternal inheritance of gynogenetic progenies. The results showed all maternal genome among offspring with no paternal genome. The cytogenetic analysis showed that meiotic gynogenetic diploids possessed 120 chromosomes in metaphase plates, while haploid control groups N1-3 possessed 60 chromosomes.