Homologous Rearranged DNA can Change Phenotype and Genotype of the Host by Transgenic Method and a QTL Related to Weight was Obtained from it

Abstract

The research study aim at looking for a simple way to obtain mutant while know what change in the genome of the host. We rearrange carp genomic DNA by digestion, ligation and addition of adaptor and then transferred the homologous rearranged DNA into carp eggs. The results showed that introduction of the homologous rearranged DNA slightly decreased the hatchability of fertilized eggs. PCR products with primers against adaptors amplified from offspring carps had different sizes compared with those amplified from the parent carps, indicating that shuffled genomic DNA has been incorporated into the genomes of offspring. Different size of PCR fragments were obtained after amplification of DNA from two small-size carps that has ceased to develop. Four clones of introducing DNA were sequenced and most of them were microsatellite DNA. Based on one of these sequences, we designed three forward and one reverse primer to amplify the genomic DNA from normal carps and we found that the amplified sequences were homologous rearranged DNA. Four transgenic fish with large body weight were selected as the father and hybridized with common female carp. We gained four groups of offspring. The muscle tissue was chosen as the sample for amplification of introducing DNA fragments. The separation of introducing DNA in three groups is confusing but clear in one group. Further analysis on the group with clear separation shows that the introducing sequence can make the weight of the host drift to the large direction and lower the differentiation between individuals with such sequence. The sequence has no coding function and no region similar to the known regulatory sequence. The study shown that the homologous rearranged DNA can be integrated into the genome of the host and make impact on the host both in genotype and phenotype.