ISSN 10227954, Russian Journal of Genetics, 2012, Vol. 48, No. 5, pp. 543–547. © Pleiades Publishing, Inc., 2012.
Corticotropinreleasing hormone (
) is a hor
mone releasing corticotropin acid produced in the
hypothalamus by the paraventricular nucleus (
Acting via specific membrane receptors, it is a main
regulator of ACTH secretion in the pituitary gland [1,
2]. Local activity of
has also been discovered i.a.
in placenta, liver, stomach, endocrine glands (pan
creas, adrenal glands, ovary, testes), where
involved in the regulatory action associated with the
response of cells to stress .
expression has been observed
in some tumors such as: carcinoid, pheochromocy
toma and neuroblastoma. Placental
ble for the regulation of ACTH secretion and the
metabolism of proopiomelanocortin (
the fetoplacental unit.
concentration in the
dam’s blood and placenta increases during gestation,
reaching the highest value during parturition .
Corticotropinreleasing hormone, as a peptide
hormone, consists of a single polypeptide chain of 41
amino acids .
structure depends on the spe
cies, but its biological activity is not speciesspecific.
from one species can
stimulate ACTH secretion in another species .
Bovine corticotropinreleasing hormone (
was localized on chromosome 14 (BTA14) . Its total
length is 1617 base pairs (bp). It has coding regions
(exon 1, 2) and two noncoding regions (introns) .
MATERIALS AND METHODS
The study was conducted on a herd including 169
Polish Holstein–Friesian strain RedandWhite cows.
The article is published in the original.
All testes animals were kept in identical environmental
conditions in the southwestern region of Poland.
Cows were standard fed, and seasonally (in spring and
summer) put out to pasture. Cows were milked twice
daily. All cows completed three consecutive lactations.
DNA was isolated from blood samples collected into
test tubes containing
. The DNA isolation
was performed using a Master Pure, kit (Epicenter
Technologies) in accordance with the manufacturer’s
instructions. The Genotype analyses were performed
using the PCRRFLP method. The analyzed SNP
consists in changing cytosine to guanine at position 22
(GenBank AF340152). Using the
designed primers amplifications were carried out and
received a specific product with a length of 307 base
pairs. Sequences of used primers were as follows:
CRH_F: 5'–CGC CCG CTA AAA TGC GAC
CHR_R: 5'–AGG CGA CTG CTG CTT CTG
The next step was to digest obtained PCR product
with restriction enzyme
. The restriction frag
ments obtained were analyzed on a 2.0% agarose gel
stained with ethidium bromide. The gels were visual
ized under UV light and documented with the use a set
of instruments for electrophoresis gel documentation
and analysis. Next, the obtained genotyping results
were statistically analyzed. The first step was estima
tion frequencies of
alleles and genotypes.
The next stage involved an analysis of associations
genotypes and milk production
traits in three consecutive lactations. Analyzed the fol
lowing traits: milk yield (kg), protein yield (kg), fat
yield (kg), milk protein content (%), and milk fat con
The Study of the SNP in the CorticotropinReleasing Hormone Gene
(Exon 2) and Milk Production Traits in Cattle
I. KowalewskaLuczak, B. Wachelko, and H. Kulig
Department of Genetics and Animal Breeding, West Pomeranian University of Technology, Szczecin 71466, Poland
Received August 04, 2011
—The aim of this study was estimate the relations between
and milk production traits
(milk yield, yield of protein and fat, content of protein and fat in milk). The study was carried on 169 Polish
Holstein–Friesian strain RedandWhite cows kept in the southwestern region of Poland. The
(exon 2) polymorphisms were detected using PCRRFLP method. The genotype and allele frequencies were
estimated and they were as follows:
—0.07. Statistically signif
) associations between
genotypes and milk production traits like milk yield and
protein yield in the second lactation were found. Moreover, the obtained results should be verified by con
ducting research on a larger group of animals and various cattle breeds.