Study On Chicken Embryo Death And Its Hereditary Reason During Hatching Period

The main aims of this study were to investigate the laws of embryo (including male and female) died during hatching period and their reasons. Fertilized and unfertilized eggs from Yellow chicken bred by Wenshi Poultry Breeding Company in China, dead embryos and normal developing embryos, and different sexes of dead embryos during hatching period were collected to investigate the effects of quality of breeding egg on fertilization of egg, embryo developing and embryo sex. Two candidate genes (RXR a and IGF2R gene) related with embryos development in human and mouse were chosen to search for SNPs and to associate gene polymorphism with the traits of dead embryo, embryo sex and the quality of breeding egg. The method used to detect the sexes of early embryos was studied.The main results in this study were listed as follows:1 The method of duplex PCR used to detect the sexes of early embryos (even the first hatching day) was primarily established.2 The peaks of dead embryos during the whole of hatching period were investigated. The peaks of dead embryos were focused on two periods (2-6, 17-19 hatching day), there were more male dead embryos than female embryos in the two periods.3 The new SNPs were discovered. 18 new SNPs were discovered in four exons and two introns in RXR a gene and 7 new SNPs were chosen to genotype by using PCR-RFLP. 2 new SNPs were discovered in the thirty-forth exon of IGF2R gene and one of them was genotyped by PCR-RFLP.4 The distribution characteristic of genotypes in dead and normal embryos was studied. For Hha I -RFLP in the second exon of RXR a gene, there were significant differences between genotypes of dead embryos and genotypes of normal embryos by the x~2 test, with the same results for ALwN I -RFLP in the thirty-forth exon of IGF2R gene.5 The distribution characteristic of genotypes in female and male were invetigated. For the Hhal-RFLP in the second exon of RXR a gene, there were significant differences between genotypes of male embryos and genotypes of female embryos, significant differences between genotypes of dead male embryos and genotypes of dead female embryos by the x~2 test.6 The association between polymorphisms and the quality of breeding eggs was analyzed by SAS 8. 0. In the mutation of BstXI -RFLP in the second exon of RXR a gene, the eggshell thickness with genotype GG of embryos was significantly higher than...