| This paper studied the effect of different mediums and temperature on the growth of the Monodus subterraneous and the effect of different food and different density of the Monodus subterraneous on the growth of Brachionus calyciflorus and explored food suddenly change induced sexual reproduction of rotifer. In order to explore the mechanism of sex-determination of rotifer, the genome DNA of Brachionus calyciflorus was extracted and amplified the conserved DM domains of Dmrt genes. Brief results are followed:(1) Monodus subterraneous grew best in BG-11 and it grew better at 27±1℃, reached 1.307×l0~8ind/ml after 25days culture. Monodus subterraneous grew badly in f/2. But after domesticated by seawater the Monodus subterraneous grew well in f/2, better than in HB-4, worse than in BG-11.(2) Brachionus calyciflorus grew best in the density 1.0×10 ind/ml of Monodus subterraneous. Suddenly changed the food could induce sexual reproduction of rotifer. Substituted Yeast for Monodus subterraneous suddenly is more effective.(3) Extracted the genome DNA of Brachionus calyciflorus successfully. Degenerate PCR was used to amplify the conserved DM domains of Dmrt genes. After DNA cloning and sequencing analysis, three different Dmrt genes were identified. Two encoded same amino acid sequence with 97% identical with Drosophila melanogaster dsx gene. But there were no any high homology sequence match to the other sequence. We speculate that Dmrt gene may play an important role in sex-determination of rotifer. |
