Intl. J. of Molecular Zoology, 2013, Vol.3, No.3, 10
-
13
http://ijmz.sophiapublisher.com
10
Research Report Open Access
Prolactin Gene Polymorphism and its Associations with Milk Production Traits
in Frieswal Cow
Saba Bukhari , Nusrat Nabi Khan , Parul Gupta , A. K.Das , Gulzar Ahmad Raher
,
D. Chakraborty ,
Akilesh Pandey
Division of Animal Genetics and Breeding, Faculty of Vety. Sci. & A.H. R.S.Pura, Jammu
Corresponding authors email:
achintyadasak@gmail.com
;
Authors
International Journal of Molecular Zoology, 2013, Vol.3, No.3 doi: 10.5376/ijmz.2013.03.0003
Received: 6 Jan., 2013
Accepted: 15 Jan., 2013
Published: 30
Jan., 2013
Copyright: © 2013, Bukhari et al. This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article:
Bukhari et al., 2013, Prolactin Gene Polymorphism and Its Associations with Milk Production Traits in Frieswal Cow, Intl. J. of Molecular Zoology, Vol.3,
No.3, 10
-
13
(
doi: 10.5376/ijmz.2013.03.0003)
Abstract
In the present study, polymorphism of
PRL
gene at exon-3 and its association with milk production traits inFrieswal cattle
was investigated. Prolactin (
PRL
)
gene exerts multiple effects on the mammary gland include mammogenesis, lactogenesis and
galactopoiesis. In order to evaluate the
PRL
gene polymorphism, the restriction fragment length polymorphism (RFLP) method was
employed in this research. Blood samples were collected from randomly chosen 54 Frieswal lactating cows. Genomic DNA was
extracted from venous blood by the method of John et al (1991) with slight modification and amplified by polymerase chain reaction
technique. The
PRL
gene of the Frieswal cattle was amplified to generate a 156 bp fragment. The PCR products were electrophoresed
on 2% agarose gel and stained by ethidium bromide. Then they were digested of amplicons with
Rsa
I, which revealed two alleles A
and B. Data were analyzed by using Pop GenePopgene32 software package and association was analyzed by simple analysis of
variance model. In this population, AA, AB, and BB genotypes were identified with 0.315, 0.629 and 0.056 frequencies, respectively.
Allele frequencies of A and B were 0.630 and 0.370, respectively. The significant (P<0.05) chi-square value in Frieswal cattle breeds
showed that the studied population was not in Hardy-Weinberg equilibrium. It is concluded from the results of present study that the
animals of BB genotype for higher lactation length and AB genotype for lactation yield and animals of AA genotype for minimum
service period may be selected for future breeding.
Keywords
Frieswal; Milk production traits; PCR-RFLP; Polymorphism; Prolactin gene
Introduction
Prolactin (
PRL
)
is the best known hormone for the
multiple effects it exerts on the mammary gland. The
varied effects of
PRL
on the mammary gland include
growth and development of the mammary gland
(
mammogenesis), synthesis of milk (lactogenesis) and
maintenance of milk secretion (galactopoiesis). Hence,
PRL
gene is a potential quantitative trait locus and
genetic marker of production traits in dairy cattle
(
Brym et al, 2005). Bovine
PRL
gene has been located
on chromosome 23 and is composed of five exons and
four introns with an overall length of approximately
10
kb encoding the 199 amino-acid mature protein
(
Camper et al, 1984). A silent A→G transition
mutation at the codon for amino acid 103 in exon-3 of
size 156 bp bovine
PRL
gene gives rise to a
polymorphic
Rsa
I (Rhodopseudomonas sphaeroides).
This site has become a popular genetic marker used
for genetic characterization of cattle populations by
means of PCR-RFLP analysis (Chrenek et al, 1998;
Dybus et al, 2005). Many workers have reported that
PRL
gene is highly polymorphic and has been found
associated with milk production (Alipanah et al, 2008;
Maksymiec et al, 2008; Ghasemi et al, 2009). The
present study was conducted to study polymorphism
in the
PRL
gene and its association with milk
production in Frieswal cattle.
1
Statistical Analysis
The frequency of
PRL
gene allele A and B and
genotype in each breed were estimated using
the
POPGENE Popgene software package (Yeh et al
,
1999).
Frequencies of distribution of alleles within the
herds were compared using the Chi-square test. Milk
productivity traits like lactation length, lactation yield
and service period were analysed using the simple
analysis of variance model as given below:
Y
ij
= µ + G
i
+ e
ij
Where, Y
ij
is the milk productivity trait of the jth cattle
for ith genotype, µ is overall mean, G
i
is the effect of