PCR-SSCP analysis of leptin gene and its association with milk production traits in river buffalo (Bubalus bubalis)

Polymorphism detection of <i>DGAT1</i> and <i>Lep</i> genes in Anatolian water buffalo (<i>Bubalus bubalis</i>) populations in Turkey

Acyl-CoA: diacylglycerol–acyltransferase 1 (DGAT1) enzyme plays a key role in controlling the synthesis rate triglyceride from diacylglycerol. Leptin (LP, OB, obese) is an important hormone that synthesizes mostly from adipose tissue and regulates glucose metabolism and homeostasis. DGAT1 and Lep genes are closely related to reproduction, growth, milk yield and composition in water buffalo breeds. This study aimed to identify genetic variation in the DGAT1 and Lep gene regions in 150 water buffalo individuals from five different provinces of Turkey using DNA sequencing. A total of 38 nucleotide variations and indels have identified 761 bp long partial intron 2 and exon 3 and 5′ UTR regions of the Lep gene in Anatolian water buffalo populations; 422 bp long partial exon 7–9 and exon 8 regions of DGAT1 gene were amplified and two mutations were defined in the point of 155 and 275 nucleotide that is three genotypes for S allele and Y allele of DGAT1 gene in intron 7 in Anatolian buffalo populations, respectively. These SNPs may have an effect on reproduction, growth, milk yield and composition in water buffalo populations and may prove to be useful for water buffalo breeding.

Association of genetic polymorphism in leptin gene with growth, reproduction and production traits in Sahiwal cows

The present study explored the association between single nucleotide polymorphisms (SNPs) in leptin gene with various economic traits (body weight at different age, first lactation reproduction and production traits) in Sahiwal cows. PCR-RFLP of 522 bp fragment comprising partial intron 2 and exon 3 of leptin gene, carried out using BsaAI restriction endonuclease, revealed three genotypes (GG, AG and AA) at position G93263736A in chromosome 4 with genotypic frequencies of 0.39, 0.52 and 0.09 respectively. The allele frequencies were 0.65 for the G allele and 0.35 for the A allele. General Linear Model (GLM) analysis revealed significant association of SNP G93263736A with growth and first lactation production traits. The present study supports that SNP in leptin gene could be used as an aid to selection for improving different economic traits in Sahiwal cows.

Systematic analyses for candidate genes of milk production traits in water buffalo (Bubalus Bubalis)

Water buffalo (Bubalus bubalis) is of great economic importance as a provider of milk and meat in many countries. However, the milk yield of buffalo is much lower than that of Holstein cows. Selection of candidate genes related to milk production traits can be applied to improve buffalo milk performance. A systematic review of studies of these candidate genes will be greatly beneficial for researchers to timely and efficiently understand the research development of molecular markers for buffalo milk production traits. Here, we identified and classified the candidate genes associated with buffalo milk production traits. A total of 517 candidate genes have been identified as being associated with milk performance in different buffalo breeds. Nineteen candidate genes containing 47 mutation sites have been identified using the candidate gene approach. In addition, 499 candidate genes have been identified in six genome-wide association studies (GWASes) including two studies performed with the bovine SNP chip and four studies with the buffalo SNP chip. Genes CTNND2 (catenin delta 2), APOB (apolipoprotein B), FHIT (fragile histidine triad) and ESRRG (estrogen related receptor gamma) were identified in at least two GWASes. These four genes, especially APOB, deserve further study to explore regulatory roles in buffalo milk production. With growth in the number of buffalo genomic studies, more candidate genes associated with buffalo milk production traits will be identified. Therefore, future studies, such as those investigating gene location and functional analyses, are necessary to facilitate the exploitation of genetic potential and the improvement of buffalo milk performance.

PCR-SSCP analysis of MDGI gene and its association with milk production traits in river buffalo (Bubalus bubalis)

In this study, we investigated the genetic variation within 3'UTR of Mammary-Derived Growth Inhibitor (MDGI) gene of buffalo using PCR-SSCP and sequencing; and also analyzed association of polymorphism with the milk production traits. The study revealed two conformational patterns, 'A' and 'B' among 234 Mehsana buffaloes maintained with their records in the field and at farm. The frequency of SSCP variant 'A' was found to be invariably high in the buffalo population under study. Further, association analysis of SSCP variants with various milk production and milk quality traits indicated no significant effect on any of the traits investigated. Sequencing of SSCP variant 'A' showed homozygous G/G and A/A and 'B' had heterozygous G/C and A/G at positions +124 and +140 respectively, in the 3'UTR of buffalo MDGI. The preliminary results showed the substantial variations in the distribution of SSCP variants' frequencies within Mehsana buffaloes, however these variants had non-significant association with milk yield, fat yield and fat percentage in Mehsana buffaloes.

Association analysis of polymorphism in thyroglobulin gene promoter with milk production traits in riverine buffalo (Bubalus bubalis)

Polymorphism within the promoter region of bovine thyroglobulin has been reported to be associated with milk and meat quality. In this study, we investigated the genetic variation within thyroglobulin promoter region of swamp and riverine buffaloes using PCR-SSCP technique and sequencing, and also analyzing association of polymorphism with the milk production traits. The study revealed four conformational patterns, A, B, C, and D among 323 buffaloes of two riverine breeds and different swamp populations. The frequency of SSCP variant 'A' was found to be invariably high among all buffalo populations. Variant 'C' was found to be absent in pure swamp population and present with higher frequency among riverine dairy breeds Mehsana and Nili Ravi. Frequency of D variant was observed to be highest in buffalo population, representing riverine and hybrid types. Sequencing of three representative PCR products of each of the SSCP variants, revealed three polymorphic sites responsible, 33C > T, 176G > T and 221C > T, in the buffalo TG promoter region. Further, association studies of SSCP variants with various milk production and milk quality traits indicated significant effect on fat percentage in buffaloes belonging to Mehsana and Nili Ravi dairy breeds. The preliminary results also showed the substantial variations in the distribution of SSCP variants' frequencies across swamp and riverine buffaloes, two distinct populations being reared for meat and milk production, respectively.

Effects of a single nucleotide polymorphism in the leptin gene on the productive traits of dairy buffaloes (Bubalus bubalis)

The gene responsible for coding the leptin hormone has been associated with productive and reproductive traits in cattle. In dairy cattle, different polymorphisms found in the leptin gene have been associated with several traits of economic interest, such as energy balance, milk yield and composition, live weight, fertility and dry matter consumption. The aim of this study was to detect genetic variability in the leptin gene of buffaloes and to test possible associations with milk yield, fat and protein percentages, age at first calving and first calving interval. Three genotypes (AA, AG and GG) were identified by polymerase chain reaction-restriction fragment length polymorphism, which presented genotypic frequencies of 0.30, 0.54 and 0.16, respectively. The allele frequencies were 0.57 for the A allele and 0.43 for the G allele. No significant effects were found in the present study, but there is an indicative that leptin gene affects lipid metabolism.