Molecular Markers for Metabolic Adaptation in Dairy Cows: SNAI2 Gene Variations

Background: Healthy transition from non-lactating pregnant state to non-pregnant lactating state is an important in the profitability of dairying. Though feeding and managemental practices play an important role in the adaptation to transition, animals kept on similar feeding and management exhibit differences in adaptation indicating an underlying genetic cause. In the present study, the sequence of gene SNAI2, which is considered to have an effect on metabolic adaptability has been compared among animals with apparently varying adaptability, as indicated by their β-hydroxy butyric acid (BHBA) concentration. Methods: During the period from August 2018 to May 2019, blood was collected and serum was separated from 30 pregnant cross bred (belonging to Sunandini genetic group of cross bred cattle of Kerala) dairy cows at fortnightly intervals from four weeks before the predicted day of parturition until four weeks after parturition. Concentration of BHBA was determined. Based on BHBA concentration the animals were sorted into two groups (High BHBA and low BHBA) using cluster analysis. Blood was collected, DNA extracted and SNAI2 gene amplified using custom synthesised primers. Amplicons from representative animals of each group were sequenced. The sequences obtained were aligned and compared using clustal-ω. Result: The comparison of the sequence of SNAI2 gene amongst the animals having high BHBA and those with low BHBA revealed two variations between the groups, one at promoter region, 61 bp upstream to the gene and other was at exonic region at 1560 bp. In silico structural analysis revealed difference in protein structure. The changes observed in the gene SNAI2 between the sets of animals grouped based on BHBA has to be studied on a larger population to ascertain the suitability of them being used as markers of genetic selection for metabolic adaptability, which in turn can increase the profitability of dairying.

Targeted sequencing of NOTCH signaling pathway genes and association analysis of variants correlated with mandibular prognathism

Introduction The purpose of this study was to systematically identify variants in NOTCH signaling pathway genes that correlate with mandibular prognathism (MP) in the general Chinese population. Methods Targeted sequencing of NOTCH signaling pathway genes was conducted in 199 MP individuals and 197 class I malocclusion control individuals. The associations of common and rare variants with MP, cephalometric parameters, and continuous cephalometric phenotypes were analyzed by principal component (PC) analysis. The associations between rare variants and MP were tested for each gene. Results Six SNPs, including rs415929, rs520688, and rs423023 in an exonic region of NOTCH4; rs1044006 in an exonic region of NOTCH3; rs1051415 in an exonic region of JAG1; and rs75236173 in the 3′-untranslated region (3′-UTR) of NUMB were associated with MP (P < 0.05). One common variant, rs1051415, in an exonic region of JAG1 was significantly related to PC1 (P = 3.608 × 10− 4), which explained 24.3% of the overall phenotypic variation observed and corresponded to the sagittal mandibular position towards the maxilla, ranging from a posterior positioned mandible to an anterior positioned mandible. Additionally, 41 other variants were associated with PC1–5 (P < 0.05). With respect to rare variant analysis, variants within the EP300, NCOR2, and PSEN2 gene showed an association with MP (t < 0 .05). Conclusions An association between NOTCH signaling pathway genes and MP has been identified.