Characterization of single nucleotide polymorphisms (SNPs) in the 5'-flanking region of bovine lactoferrin gene in the local and holstein cattle of Iran

Lactoferrin (Lf), an iron binding glycoprotein, has a variety of physiological roles and its foremost is antimicrobial properties. Therefore, the lactoferrin gene can be considered as a potential candidate gene for resistance to mastitis.

This study was carried out to determine the haplotype frequency of the 5'-flanking region of bovine lactoferrin gene in local and Holstein cattle breeds of Iran using PCR-SSCPand DNA sequencing.

Genomic DNA was isolated from 100 blood samples of two cattle breeds (50 Local, 50 Holstein). Two new primer pairs were designed from Lf sequence to amplify a part of 5'-flanking region of the gene. The amplified fragment was screened by single strand conformation polymorphism (SSCP) and DNA sequencing. The multiple alignments were carried out for the nucleotide sequences of different SSCPpatterns. In silico analysis of identified single nucleotide polymorphisms (SNPs) within the 5'-flanking region of bovine Lf gene was screened, to identify any association on transcription factor binding affinity. REULTS: Analysis of the whole samples revealed three SSCP patterns (A, B and C) for amplified fragment that C haplotype was the only variant identified in local breed samples. The bioinformatics analysis revealed that the Tto G trans version at position -602 created an AML-1 transcription binding site in combined genotype A. In -586 position, Tto C transition abolished binding site of AML-1 transcription factor.

Therefore, to apply Lf gene for marker-assisted selection, additional studies are required to evaluate the functional role of these identified polymorphic sites on gene expression and somatic cell counts in cattle.