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


Department of Animal Sciences, Faculty of Agriculture, Yasouj University, Yasouj-Iran


BACKGROUND: 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. OBJECTIVES:
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. METHODS: 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. CONCLUSIONS: 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.