Association between LEPR and MC4R genes polymorphisms and composition of milk from sows of dam line

Whole genome sequencing of simmental cattle for SNP and CNV discovery

BACKGROUD

The single nucleotide polymorphisms (SNPs) and copy number variations (CNVs) are two major genomic variants, which play crucial roles in evolutionary and phenotypic diversity.

RESULTS

In this study, we performed a comprehensive analysis to explore the genetic variations (SNPs and CNVs) of high sperm motility (HSM) and poor sperm motility (PSM) Simmental bulls using the high-coverage (25×) short-read next generation sequencing and single-molecule long reads sequencing data. A total of ~ 15 million SNPs and 2,944 CNV regions (CNVRs) were detected in Simmental bulls, and a set of positive selected genes (PSGs) and CNVRs were found to be overlapped with quantitative trait loci (QTLs) involving immunity, muscle development, reproduction, etc. In addition, we detected two new variants in LEPR, which may be related to the artificial breeding to improve important economic traits. Moreover, a set of genes and pathways functionally related to male fertility were identified. Remarkably, a CNV on SPAG16 (chr2:101,427,468 - 101,429,883) was completely deleted in all poor sperm motility (PSM) bulls and half of the bulls in high sperm motility (HSM), which may play a crucial role in the bull-fertility.

CONCLUSIONS

In conclusion, this study provides a valuable genetic variation resource for the cattle breeding and selection programs.

Effect of the polymorphism of genes related to lactogenesis in pigs on colostrum and milk composition and on rearing performance of piglets

The aim of the study was a search for new polymorphisms in the genes related to lactogenesis, including lactose synthesis in colostrum and milk, and determine their relationship with the content of colostrum and milk components and body weight of the piglets. Colostrum and milk were sampled during the second lactation on d 1, 7, 14 and 21 from 112 sows of Polish Large White (PLW) and Polish Landrace (PL). The piglets’ rearing performance was determined based on the number and body weight at 1, 7, 14 and 21 d of age. In the study six polymorphisms located in different genes were analysed. Among the six polymorphisms under analysis, those identified in the B4GALT1 genes had the most significant effect on colostrum and milk composition and the piglets’ body weight changes. Sows of the B4GALT1GG genotype, when compared to those of B4GALT1AA , produced colostrum and milk with a significantly lower lactose content and reared piglets with a substantially higher body weight (by 0.30 kg) at 21 d of age.

A Comparative Review of the Extrinsic and Intrinsic Factors Regulating Lactose Synthesis

Milk is critical for the survival of all mammalian offspring, where its production by a mammary gland is also positively associated with its lactose concentration. A clearer understanding of the factors that regulate lactose synthesis stands to direct strategies for improving neonatal health while also highlighting opportunities to manipulate and improve milk production and composition. In this review we draw a cross-species comparison of the extra- and intramammary factors that regulate lactose synthesis, with a special focus on humans, dairy animals, and rodents. We outline the various factors known to influence lactose synthesis including diet, hormones, and substrate supply, as well as the intracellular molecular and genetic mechanisms. We also discuss the strengths and limitations of various in vivo and in vitro systems for the study of lactose synthesis, which remains an important research gap.