Jiaqi Chen’s scientific contributions

Background: Pigs are vital agricultural animals, with growth traits serving as key indicators of their quality. Methods: In this study, we examined the mRNA expression of ENPP1 as a candidate gene in heart, liver, spleen, lungs, and kidneys at 3 days and 6 months of age by real-time polymerase chain reaction method and single-nucleotide polymorphism (SNP) loci in 165 Xiangsu pigs by Sanger sequencing. Results: The expression of ENPP1 in different tissues of Xiangsu pigs at different stages was significantly different, and it had high conservation in different species.. Sequence alignment with reference data identified five SNP sites: g.64275T→C and g.64429G→A in intron 19, g.64850T→C and g.64911G→A in intron 20, and g.64527T→C in exon 20. Association analysis revealed that g.64275T→C, g.64429G→A, and g.64527T→C significantly influence the growth performance of Xiangsu pigs (p < 0.05). Conclusions: These findings suggest that ENPP1 polymorphisms are closely associated with growth traits in Xiangsu pigs and may provide valuable insights for molecular breeding of this breed.

Objective: This study aimed to identify polymorphisms in the gene encoding the 3-hydroxy-3-methylglutaryl-CoA synthase 1, HMGCS1 , and analyze their association with slaughter characteristics, meat quality, and organ coefficients in Guizhou white goats.Methods: A total of 153 twelve-month-old Guizhou white goats (78 male and 75 female) were included in the study. Slaughter characteristics, meat quality, and organ coefficients were assessed. Association analyses between genotypes and phenotypic traits were conducted using a generalized linear model.Results: Four polymorphic loci were identified, i.e., g.15523T>C, g.15530G>C, g.18413T>C, g.19711G>A in exons 5, 8, and 9 of the HMGCS1 gene. Across all polymorphic loci, males of the same genotype generally exhibited significantly better slaughter traits compared to females of the same genotype (p<0.05). At the g.18413T>C locus, differences in shear force were observed between males and females of the same genotype and within the same sex across different genotypes (p<0.05). Organ coefficients were significantly higher in males of the same genotype compared to females (p<0.05). The g.15523T>C and g.15530G>C loci were found in strong linkage disequilibrium and significantly associated with intramuscular fat content (p<0.05). Fat content in diploid Hap2/2 individuals was significantly higher than in Hap1/1 and Hap1/2 (p<0.05). At the g.19711G>A locus, female goats with the CC genotype showed significantly higher levels of dry matter compared to male goats of the same genotype and female goats of other genotypes within the group. Organ coefficients for the liver and hooves in male goats were significantly higher than in females of the same genotype (p<0.05).Conclusion: The strongly linked loci g.15523T>C and g.15530G>C were significantly associated with intramuscular fat content and could be used as molecular markers for enhancing this trait in goat breeding programs, fostering the development of goat production.

Oxidized low-density lipoprotein receptor-1 (OLR1) encodes a low-density lipoprotein receptor belonging to the C-type lectin superfamily, which is closely related to reproduction. OLR1 is associated with fecundity in Awassi sheep. However, its effect on litter size has not been investigated in goats. In this study, OLR1 sequences and their mRNA expression levels in the gonadal axis of Guizhou white goats were evaluated to investigate the relationship between gene polymorphisms and litter size. In addition, the potential effects of a nonsynonymous substitution were evaluated using a bioinformatics approach. The expression levels of OLR1 were highest in the uterus of mothers with multiple kids and highest in the ovaries of mothers with single kids. OLR1 mRNA expression levels in the ovaries of mothers with single kids were two times higher than in the ovaries of mothers with multiple kids. The sequencing results revealed five SNPs in OLR1; however, only g.294 T > A, g.2260 T > C, and g.2268 C > T were significantly associated with litter size (P < 0.05). Linkage disequilibrium was detected between g.2260 T > C and g.2268 C > T (r2 = 0.322, D' = 0.6). Additionally, goats with the Hap 1/1 diplotype had a greater litter size than others (P < 0.05). g.2260 T > C was a nonsynonymous mutation that resulted in the replacement of valine with alanine at the amino acid residue 54 of the OLR1 protein. Bioinformatic analyses revealed that the p.V54A locus was relatively conserved in cloven-hoofed species. Mutations at this locus could change the local conformation and reduce the stability of OLR1, affecting its half-life and the litter size of the nanny goat. These findings confirm that OLR1 affects goat kidding traits and provide a novel insight into the regulatory mechanism underlying the effect of OLR1 on litter size.