THIS WORK aimed to search for single nucleotide polymorphisms
of gonadotropin releasing hormone receptor (GnRHR) gene in
Egyptian buffalo which involved in endocrine control of fertility. An
ultrasonographic examinations of anestrum and repeat breeders’ buffaloes
were performed prior to blood sampling through a transrectal
ultrasonography. DNA was extracted from blood and the PCR and singlestrand
conformation polymorphism (SSCP) techniques were adopted to
study of GnRHR gene polymorphism. The PCR amplified a fragment
with 240-bp in size and the SSCP results showed that there is a
genetic polymorphism with three different patterns (AA, BB and CC)
in Egyptian buffalo. The CC genotype was associated with smooth
inactive ovary, while BB genotype was associated with fertility in
buffalo. Multiple sequence alignment of the three patterns sequences
revealed that GnRHR had 5 single nucleotide polymorphisms
including one nucleotide insertion, one nucleotide deletion and 3
nucleotide substitutions. Insertion was at position 4 in pattern III. The
deletion was at position 189 in pattern III, while the 3 nucleotide
substitutions were at positions 204 (T/G), 206 (T/A) and 207 (A/T). In
conclusion, GnRHR gene could be used as a candidate marker for
fertility in Egypt.