Effects of polymorphisms of LHR and FSHR genes on sexual precocity in a Bos taurus x Bos indicusbeef composite population

Abstract

ABSTRACT. The purpose of the present research was to investigate the effects of polymorphisms of luteinizing hormone receptor (LHR) and follicle-stimulating hormone receptor (FSHR) genes, evaluated by polymerase chain reaction-restriction fragment length polymorphism in EuropeanZebu composite beef heifers from six different breed compositions. The polymorphism site analysis from digestion with HhaI and AluI restriction endonucleases allowed the genotype identification for LHR (TT, CT and CC) and FSHR (GG, CG and CC) genes. A high frequency of heterozygous animals was recorded in all breed compositions for both genes, except in two compositions for LHR. The probability of pregnancy (PP) at first breeding was used to evaluate the polymorphism effect on sexual precocity. The PP was analyzed as a binary trait, with a value of 1 (success) assigned to heifers that were diagnosed pregnant by rectal palpation and a value of 0 (failure) assigned to those that were not pregnant at that time. Heterozygous heifers showed a higher pregnancy rate (67 and 66% for LHR and FSHR genes, respectively), but no significant effects were observed for the genes studied (P = 0.9188 and 0.8831 for LHR and FSHR, respectively) on the PP. These results do not justify the inclusion of LHR and FSHR restriction fragment length polymorphism markers in selection programs for sexual precocity in beef heifers. Nevertheless, these markers make possible the genotype characterization and may be used in additional studies to evaluate the genetic structure in other bovine populations.

Effect of casein genes - beta-LGB, DGAT1, GH, and LHR - on milk production and milk composition traits in crossbred Holsteins

“…This result is consistent with that of a previous study (Shirasuna et al, 2011), which examined a Holstein population, but the frequency was different from the study of Marson et al (2008), who examined crossbred dairy cattle in their study.…”

“…The method described by Kuehn et al (2007) was used to study polymorphisms of the DGAT1 gene. PCR-RFLP and the methods described by Marson et al (2008) and Rachagani et al (2006) were used to genotype the LHR, beta-LGB, and GH genes, respectively.…”

“…The genes selected for this study included the DGAT1 gene, which is located on the bovine chromosome 14 and encodes acyl-CoA:diacylglycerol acyltransferase 1 enzyme (Grisart et al, 2002); the casein gene family, which is composed of the alpha-S1, alpha-S2, beta-, and kappa-casein genes (Mercier and Viloite, 1993;Jann et al, 2004) and is located on the bovine chromosome 6 at q31-q33; the beta-LGB gene, which is located on chromosome 11 and encodes the main protein of whey protein (Eigel et al, 1984); the GH gene, which is located on chromosome 19 in the region of bands q26-qter (Hediger et al, 1990); and the LHR gene, which is located on chromosome 11 (Marson et al, 2008). All of these genes affect milk production and milk composition.…”

Relationship between polymorphisms in exon 10 of FSHR gene and litter size in swine

“…Many studies have indicated that the FSHR gene plays important roles in human hormone secretion, menstrual cycle, ovarian development, and other reproductive processes (Sairam and Subbarayan, 1997;Marson et al, 2008;Achrekar et al, 2009a;Balkan et al, 2010;Rendina et al, 2010;Dolfin et al, 2011;Kang et al, 2012;Grigorova et al, 2008Grigorova et al, , 2013. However, the relationship between FSHR polymorphisms and reproductive traits in swine has not been thoroughly examined.…”

“…A study by Rahal et al (2000) detected 2 SNPs (C1506T and T1593C) in exon 10 of the bovine FSHR gene. Marson et al (2008) found no correlation between FSHR gene polymorphisms and precocious puberty in heifers, while a study by Sairam and Subbarayan (1997) identified a correlation between FSHR gene polymorphisms and the secretion of reproductive hormones in seasonally breeding mammals. Finally, studies by Jiang et al (2002) revealed that polymorphisms in exon 10 of the porcine FSHR gene significantly affected the number of offspring.…”