Molecular cloning and characterization, and prokaryotic expression of the GnRH1 gene obtained from Jinghai yellow chicken

Molecular cloning of the goose GnRH gene and identification of GnRH polymorphisms associated with laying traits

1. Egg-laying traits are important economic characteristics in goose production (Anser cygnoides). The gene GnRH, which encodes gonadotropin-releasing hormone, is a strong candidate gene for egg-laying traits in avian species. 2. In this study, a 3520 bp genomic sequence and a 279 bp mRNA sequence for GnRH, which encoded 92 amino acids, were determined. The GnRH DNA sequence contains four exons and three introns, and the DNA and deduced amino acid sequences were highly conserved across mammals (human, macaque, cow, and sheep) and avians (chicken, fulmar and quail). 3. Using a direct sequencing method, 46 single nucleotide polymorphisms (SNPs) were identified in the GnRH genomic sequence that were shared between two Sichuan White goose populations (217 and 208 individuals). Furthermore, 44 haplotypes were constructed using a sliding window approach. Association analysis between the SNPs and haplotypes and egg-laying traits showed that 10 SNPs affected the first egg weight, average egg weight, egg number at 48 weeks and egg number at 64 weeks. 4. These results lay the foundation for further studies of the function of GnRH in geese and provide a theoretical basis for marker-assisted selection of egg-laying traits in the Sichuan white goose population.

Complete mitogenomic and phylogenetic characteristics of the speckled wood-pigeon (Columba hodgsonii)

The speckled wood-pigeon, Columba hodgsonii, is mainly distributed in Bhutan, China, India, Laos, Myanmar, Nepal, Pakistan, and Thailand. Although there are several studies on birds in the family Columbidae, no study has focused on C. hodgsonii, a member of this family. Therefore, this study aimed to clarify the phylogenetic status of C. hodgsonii. The complete mitochondrial genome (mitogenome) of C. hodgsonii was sequenced and characterized and compared with those of other Columba species. The C. hodgsonii mitogenome was found to be 17,477 bp in size and contained 13 PCGs, two rRNAs, 22 tRNAs, and one CR. Of the 37 genes encoded by the C. hodgsonii mitogenome, 28 were on the heavy strand and nine were on the light strand. Twelve PCGs were initiated by ATN codons and one PCG harbored an incomplete termination codon (T-). The base composition of C. hodgsonii PCGs was A = 29.44%, T = 24.37%, G = 12.43%, and C = 33.76%. For the whole mitogenome, including PCGs, rRNAs, tRNAs, and the control region, the AT-skew was positive, and the GC-skew was negative. Phylogenetic analysis based on the base sequences of 13 PCGs from 28 Columbidae species and one outgroup using maximum likelihood and Bayesian inference indicated that C. hodgsonii belongs to the genus Columba and that the family Columbidae is monophyletic.