Homozygosity Analysis Of Two Artificially Gynogenetic Group In Grass Carp

Ploidy and homozygosity of two groups of artificially gynogenetic grass carp were analyzed by cytogenetical and molecular biology methods. The result indicates that the ploidy and homozygosity of these groups are accord with the criterion of gynogenetic fish, its also shows there are no phenomenon of miscellany in process of location conversion. The major studies in this paper are presented as follows:1. Measure artificially gynogenetic grass carps,common grass carps,Xiangjiang wild carps by surveying erythrocytes and nuclei size. The size and configuration of erythrocytes and nuclei of the two groups of artificially gynogenetic grass carp have no significant difference of common grass carp, and different from that in the Xiangjiang wild carp obviously.2. Test ploidy of the artificially gynogenetic grass carps,common grass carps,Xiangjiang wild carp in use of the flow cytometry. Referring to common grass carp, the relative DNA contents of two groups of gynogenetic grass carp and common grass carp are the same, contents of wild carps are twice over. So far as we know there is 48 chromosome of common grass carp, and 100 for carp. The comparison results show that there is no prominent difference between gynogenetic grass carps and ordinary grass carps on their ploidy. That is identical to the expectation.3. Analyse the homozygosity of two groups of artificially gynogenetic grass carp by RAPD—PCR method. Using statistical analysis system computer program based on genetic distances clearly revealed that average genetic distance of common grass carp and artificially gynogenetic grass carp in 2005 and in 2006 are respectively 0.0678,0.0384 and 0.0485. These indicate that the homozygosity of two artificially gynogenetic grass carp are higher than it of common grass carp, and the homozygosity of artificially gynogenetic grass carp in 2006 is lower than it in 2005.