Polymorphisms of AluI and Hin1I loci of the IGF-1R gene and their genetic effects on growth traits in Bian chickens.

Growth traits are important economic traits in broiler chicken production. AluI and Hin1I loci are two restriction sites, which are respectively located in exons 2 and 3 of the IGF-1R gene. These two loci are significantly related to the growth traits in Jinghai Yellow chickens. In this study, a correlation analysis was performed between these two loci and the growth traits of Bian chickens. The results showed a G376A mutation at the AluI site and a C919A mutation at the Hin1I site, which respectively resulted in three genotypes AA, AB, and BB in exon 2 and three genotypes CC, CD, and DD in exon 3. Correlation analysis showed that the female Bian chickens with the AA genotype of the AluI locus had higher body weights than those with the AB genotype (P < 0.05) at 8, 14, 16, and 18 weeks; individuals with CD genotype of Hin1I locus had higher body weights at 6, 8, 10, 12, and 14 weeks compared to the CC genotype (P < 0.05 or P < 0.01). Combined genotypes analysis showed that at the age of 8, 14, 16, and 18 weeks, the body weight of AACC genotype combination was higher than that of the ABCC genotype combination (P < 0.05); at the age of 6, 8, 12, 14, 16, and 18 weeks, the AACD genotype combination had higher (P < 0.05 or P < 0.01) body weight than that of the ABCC genotype.

A genome-wide association study of growth trait-related single nucleotide polymorphisms in Chinese Yancheng chickens.

Chicken (Gallus gallus) growth traits are important economic traits, and many studies have been conducted on genetic selection for body weight. However, most of these studies have detected functional chromosome mutations or regions by conventional molecular markers or gene chips. In this study, we performed a new genome-wide association study using specific-locus amplified fragment sequencing (SLAF-seq) technology in purebred Yancheng chickens. Single nucleotide polymorphisms (SNPs) that were significantly associated with phenotypic traits were identified by GAPIT-compressed mixed linear models. Eighteen SNP markers reached 5% Bonferroni genome-wide significance. A region spanning 72.3 to 82.1 Mb on GGA4 had a strong influence on growth traits. Four genes (FAM184B, KCNIP4, MIR15A, and GLI3) were closely associated with body weight. Some SNPs were coincident with previously reported quantitative trait locus regions. Our results would promote the researches of Chinese chickens and accelerate the utilization of Chinese chicken, specially Yancheng chicken.

Genetic diversity and relationships among Chinese Eucommia ulmoides cultivars revealed by sequence-related amplified polymorphism, amplified fragment length polymorphism, and inter-simple sequence repeat markers.

Sequence-related amplified polymorphism (SRAP), amplified fragment length polymorphism (AFLP), and inter-simple sequence repeat (ISSR) markers were used to estimate the genetic diversity and relationships among Eucommia ulmoides cultivars in China. A total of 240, 192, and 150 DNA fragments were detected by 10 SRAP primer combinations, 10 AFLP primer combinations, and 10 ISSR primers, among which 89.2, 65.1, and 88.0% of the fragments were polymorphic, respectively. Cluster analysis revealed that Qinzhong No. 3, Xiaoyeci, Qinzhong No. 1, and Qinzhong No. 2 formed independent clusters. The other 15 cultivars exhibited two clusters. The results of this study will help in the selection of parents for both genome mapping and crossbreeding purposes.