Candidate SNP of CACNA2D1 Gene Associated with Clinical Mastitis and Production Traits in Sahiwal (Bos taurus indicus) and Karan Fries (Bos taurus taurus × Bos taurus indicus).

The present study was conducted to identify polymorphisms in CACNA2D1 gene and their association with clinical mastitis and production traits. Exon 18 and its flanking regions were screened for the presence of SNPs. Statistical analysis was performed to identify association of period of birth, breed, and genotype with mastitis incidence on randomly selected 103 Sahiwal and 102 Karan Fries cattle. PCR-RFLP analysis revealed that g.38819398G > A mutation in exon 18 (269 bp amplicon) of CACNA2D1 gene resolved into AA, AG, and GG genotypes in Sahiwal and Karan Fries cattle. Wald chi-square analysis revealed that the period of birth, breed, and genotype were significantly associated with mastitis incidence. GG genotyped cattle were found to be less susceptible to mastitis. Least square analysis revealed that GG and AG genotype animals of G38819398A SNP of CACNA2D1 gene in Sahiwal as well as in Karan Fries cattle were associated with higher average milk yields during 1st, 2nd, and 3rd lactations (P < 0.01). These observations and their differential association with the incidence of mastitis and production traits can be utilized as an aid to selection for simultaneous improvement of both antagonistic traits; however, validation of results on large number of animals is warranted.

Magotra A ，Gupta ID ，Verma A ，Alex R ，Mr V ，Ahmad T ... -  《-》

Association of udder type traits with single nucleotide polymorphisms in Sahiwal (Bos indicus) and Karan Fries (Bos taurus × Bos indicus) cattle.

Udder structure of milking cows is not merely vital to display the visual characteristics, but also important for high milk output and low mastitis risk incidence as well. The present study measured different udder type traits in Sahiwal () and Karan Fries () and investigated their association with single nucleotide polymorphisms in Vitamin D Receptor and Protein Tyrosine Phosphatase, Receptor Type, R genes. GG genotype of SNP rs454303072 was found to have wider rear udder, larger udder circumference, longer distance between fore-rear teats and left-right teats in Karan Fries cattle. Whereas, in Sahiwal cattle, AA genotype of this SNP was found to be associated with the higher and wider rear udder, larger udder circumference and wider udder. AA genotype of SNP rs382671389 was found to be associated with longer fore teat in Karan Fries cattle. The TT and CC genotype of SNP rs435289107 was associated with udder type traits in Karan Fries and Sahiwal cattle respectively. These results suggest that BTA 5 harbors genomic regions associated with udder traits in and x cattle.

Sinha R ，Sinha B ，Kumari R ，M R V ，Sharma N ，Verma A ，Gupta ID ... -  《-》

Novel SNP identification in exon 3 of HSP90AA1 gene and their association with heat tolerance traits in Karan Fries (Bos taurus × Bos indicus) cows under tropical climatic condition.

Heat shock proteins (HSPs) act as molecular chaperones those are preferentially transcribed in respose to heat stress and the polymorphism in HSP genes associated with heat tolerance traits in cows. HSP90AA1 gene has been mapped on Bos taurus autosome 21 (BTA-21) and spans nearly 5368 bp comprising of 11 exons out of which the first exon does not translate. The present study was done on Karan Fries (5/8 HF × 3/8 Tharparkar) cows reared in tropical climate with the objectives of identifying single-nucleotide polymorphisms (SNPs) in targeted regions (exon 3) of HSP90AA1 gene and analyzing their association with heat tolerance traits in Karan Fries cows. Respiration rate (RR) and rectal temperature (RT) were recorded once daily for four consecutive days during probable extreme hours in different seasons or temperature humidity index (THI), viz., winter, spring, and summer. For detecting single-nucleotide polymorphisms, sequence data were analyzed using BioEdit software (version 7.2). Comparative sequence analysis of HSP90AA1 gene showed point mutation, viz., g.1209A>G (exon 3) as compared to Bos taurus (NCBI Ref Seq: AC_000178.1). Association analysis indicated that THI was influenced (P < 0.01) by RR, RT, and HTC. Similarly, SNPs at locus g.1209A>G were categorized into three genotypes, i.e., AA, AG, and GG, and the least squares means (LSMEANS) of RR, RT, and HTC for GG (homozygous) genotype were significantly lower (P < 0.01) than AA (homozygous) and AG (heterozygous) genotypes. These findings may partly suggest that cows with GG genotypes were favored for heat tolerance trait, which can be used as an aid to selection for thermo-tolerance Karan Fries cows for better adaptation in subtropical and tropical hot climate.

Kumar R ，Gupta ID ，Verma A ，Singh SV ，Verma N ，Vineeth MR ，Magotra A ，Das R ... -  《-》

Polymorphism in DNA repair gene BRCA1 associated with clinical mastitis and production traits in indigenous dairy cattle.

The present study was conducted on Karan Fries cows to identify SNPs in breast cancer 1 (BRCA1) gene and their association with inflammation of mammary gland and production traits. Chi square analysis showed significant association of both SNPs i.e. G43737229T (P < 0.01) and G43761121A (P < 0.05) with incidence of clinical mastitis. Logistic modeling showed that GG genotype cows of G43737229T SNP was less susceptible to mastitis in comparison to TT genotype cows as the odds ratio of TT against GG for the non-incidence of mastitis was less i.e. 0.23. Whereas, cows with genotype AA of G43761121A SNP were less prone to clinical mastitis in comparison to GG genotype cows. G-T haplotype and GGTT combined genotype exhibited maximum mastitis incidences. Least squares analysis revealed significant association of G43737229T SNP with total milk yield (P < 0.01), 305 days milk yield (P < 0.01) and lactation length (P < 0.05). The TT and GT genotyped Karan Fries cows were associated with higher milk yields during first and second lactation, as well as with first lactation length. These observations on SNPs, genotypes and combined genotypes of BRCA1 gene and their differential association with the incidence of mastitis and production traits can be utilized as an aid to selection for simultaneous improvement of both antagonistic traits.

Magotra A ，Gupta ID ，Ahmad T ，Alex R ... -  《-》

Associations between polymorphisms of LAP3 and SIRT1 genes with clinical mastitis and milk production traits in Sahiwal and Karan Fries dairy cattle.

Bovine mastitis continues to remain as the most challenging disease in dairy cattle, as a result improvement of selection methods has great economic relevance while a deeper understanding of the genetic mechanisms regulating milk production traits and mastitis is of general scientific interest. This study aimed to evaluate the association of SNPs of the LAP3 and SIRT1 genes with estimated breeding values (EBVs) of milk production traits and clinical mastitis in dairy cattle of Indian origin. DNA samples from 263 animals (Sahiwal and Karan Fries cattle) were genotyped by PCR-RFLP to assess their pattern of genetic variation. EBVs of milk production traits and phenotypic records of incidences of clinical mastitis were used for association analysis. A total of 9 SNPs were identified, including three (rs110932626: A>G, rs716493845: C>T and rs43702363: C>T) in intron 12, four (g.24904G>C, rs110839532: G>T, rs43702361: T>C and rs41255599: C>T) in exon 13 and within 3'UTR of LAP3 gene and two (rs110250233: G>A and rs42140046: C>G) in the promoter region of SIRT1 gene. Eight of these identified SNPs were chosen for subsequent genotyping and association analyses. Association analysis revealed that SNP rs41255599: C>T was significantly associated with lactation milk yield, 305-day milk yield, 305-day fat yield, 305-day solid not fat yield, lactation length and incidence of clinical mastitis (p < 0.05) in Sahiwal cattle. For Karan Fries cattle, two SNPs including rs110932626: A>G and rs43702363: C>T showed significant association with 305-day milk yield. Overall, these findings provide evidence for association of the LAP3 gene with milk production traits and clinical mastitis in dairy cattle, indicating the potential role of LAP3 variants in these traits.

Worku D ，Gowane GR ，Mukherjee A ，Alex R ，Joshi P ，Verma A ... -  《Veterinary Medicine and Science》