Polymorphisms of beta-lactoglobulin promoter region in three Sicilian goat breeds

Abstract

Several beta-lactoglobulin (BLG) polymorphisms have been described within the proximal promoter region and coding region of the caprine gene, although no genetic variants affecting the protein amino acid composition and/or expression level have been characterized so far. Binding sites for several transcription factors (TFs) are present in the BLG promoter region. The aims of this work were to sequence the full-length promoter region of three Sicilian goat breeds in order to identify polymorphisms, analyze the identified haplotypes, search for differences between breeds for the presence of polymorphisms in this gene region, search for putative TFs binding sites, and check if polymorphisms lay within the identified TFs binding sites. The promoter region of BLG gene in Sicilian goat breeds showed high level of polymorphism due to the presence of 36 single nucleotide polymorphisms (SNPs). Association between polymorphic sites was computed within the whole sample analyzed and 18 haplotypes were inferred. Binding sites for three milk protein binding factors (MPBFs) and four nuclear factor-I (NF-I) were found within BLG promoter region based on the ovine sequence. The identification of some SNPs within TFs binding sites allowed hypothesizing the loss of TFs. Further studies are in progress to evaluate the effect of these mutations on binding affinity of TFs, the functional interaction of the TFs with the goat BLG promoter, and the relationship of the polymorphisms with BLG gene expression and milk production and composition.

Genetic Factors that Regulate Milk Protein and Lipid Composition in Goats

“…Pena et al (2000) also found two SNP at exon 7 encoding the 3'UTR. In close resemblance with results contributed by Ballester et al (2005), Sardina et al (2011) reported extensive variability at the BLG promoter, with a total of 36 SNP identified in a panel of Sicilian goats. Several of the SNP identified by Ballester et al (2005) and Sardina et al (2011) have been mapped to potential transcription factor binding sites, so they might be good candidates to regulate BLG mRNA expression.…”

“…In close resemblance with results contributed by Ballester et al (2005), Sardina et al (2011) reported extensive variability at the BLG promoter, with a total of 36 SNP identified in a panel of Sicilian goats. Several of the SNP identified by Ballester et al (2005) and Sardina et al (2011) have been mapped to potential transcription factor binding sites, so they might be good candidates to regulate BLG mRNA expression. Pending tasks are to investigate the existence of quantitative differences (in terms of BLG mRNA) between promoter alleles as well as to find out if they have a detectable influence on milk composition.…”

Associations between two novel rSNPs in 5′-flanking region of the bovine casein gene cluster and milk performance traits

“…The main difference of this inquiry from previously observed ones (Prinzenberg et al, 2003;Sanders et al, 2006;Kuss et al, 2005;Sardina et al, 2011) is the investigation of regulatory regions located more distally from CSN1S1 gene start codon (up to -15 kb) that allow describing new polymorphic sites which could affect some milk performance traits.…”

“…⁎ Last year the polymorphisms in regulatory regions of the cattle casein gene cluster and their associations with the milk performance traits were investigated (Prinzenberg et al, 2003;Sanders et al, 2006;Kuss et al, 2005 andSardina et al, 2011). Two new alleles were revealed in Holstein cattle population by conformational polymorphism analysis in promoter region of CSN1S1 gene including transcription factor binding sites (Prinzenberg et al, 2003).…”

Differential Expression of the Alpha S1 Casein and Beta-Lactoglobulin Genes in Different Physiological Stages of the Adani Goats Mammary Glands

“…Many genetic polymorphisms in the promoter and coding region of this gene have been reported in goat (20,21), sheep (22,23), cattle (2,24), and buffalo (25). BLG and CSN1S1 are very important in the milk industry and animal breeding.…”