B4GALT1, LHR, FSHR and IGF2 polymorphisms and scrotal circumference in Nellore bulls / Polimorfismos dos genes B4GALT1, LHR, FSHR e IGF2 e perímetro escrotal em touros da raça Nelore

We assessed whether single nucleotide polymorphisms (SNPs) in the genes beta 1,4- galactosyltransferase (B4GALT1), luteinizing hormone receptor (LHR), follicle-stimulating hormone receptor (FSHR) and insulin-like growth factor 2 (IGF2) could be molecular markers for scrotal circumference (SC) in Nellore bulls. Animals with positive (+, n = 104) and negative (-, n = 74) expected progeny difference for scrotal circumference at 365 days (EPD SC 365) were selected and their SNPs were analyzed by restriction fragment length polymorphism (RFLP). The correlation between EPD SC 365 and expected progeny difference for age at first birth (EPD AFB) was also investigated. The SNPs in B4GALT1 and FSHR was not different between two groups analyzed. The CC genotype for LHR gene was most frequent in animals with EPD SC 365(+), whereas the TT was most frequent in the EPD SC 365(-). For IGF2 the CT and CC were the most frequent genotypes observed in animals with positive and negative EPD SC 365, respectively. The EPD SC 365 was negatively correlated with the EPD AFB (r = 0.23). We suggest that CC and TT genotypes for LHR and IGF2, respectively, could be possible molecular markers for SC selection in Nellore bulls, that can also predict for AFB.(AU)

Foram avaliados se polimorfismos de base única (SNPs) presentes nos genes beta-1,4- galactosiltransferase (B4GALT1), receptor de hormônio luteinizante (LHR), receptor de hormônio folículo estimulante (FSHR) e fator de crescimento semelhante à insulina 2 (IGF2) poderiam ser marcadores moleculares para o perímetro escrotal (PE) em touros da raça Nelore. Animais com diferença esperada de progênie positiva (+, n = 104) e negativa (-, n = 74) para PE aos 365 dias (DEP PE 365) foram selecionados e seus SNPs foram analisados utilizando a técnica de polimorfismo de comprimento de fragmentos de restrição (RFLP). A correlação entre DEP PE 365 e idade ao primeiro parto (DEP IPP) também foi investigada. Os SNPs dos genes B4GALT1 e FSHR não apresentaram diferença entre os dois grupos analisados. O genótipo CC para o gene LHR foi mais freqüente em animais com DEP PE 365 (+), enquanto o TT foi mais frequente no grupo com DEP PE 365 (-). Para o gene IGF2, os genótipos CT e CC foram mais freqüentes em animais com DEP PE 365 positiva e negativa, respectivamente. A DEP PE 365 foi negativamente correlacionada com a DEP IPP (r = -0,23). O genótipo CC para o gene LHR e genótipo TT para o gene IGF2 podem ser possíveis marcadores de PE para a seleção assistida em touros da raça Nelore, podendo ser ainda preditores para IPP.(AU)

B4GALT1, LHR, FSHR and IGF2 polymorphisms and scrotal circumference in Nellore bulls / Polimorfismos dos genes B4GALT1, LHR, FSHR e IGF2 e perímetro escrotal em touros da raça Nelore

We assessed whether single nucleotide polymorphisms (SNPs) in the genes beta 1,4- galactosyltransferase (B4GALT1), luteinizing hormone receptor (LHR), follicle-stimulating hormone receptor (FSHR) and insulin-like growth factor 2 (IGF2) could be molecular markers for scrotal circumference (SC) in Nellore bulls. Animals with positive (+, n = 104) and negative (-, n = 74) expected progeny difference for scrotal circumference at 365 days (EPD SC 365) were selected and their SNPs were analyzed by restriction fragment length polymorphism (RFLP). The correlation between EPD SC 365 and expected progeny difference for age at first birth (EPD AFB) was also investigated. The SNPs in B4GALT1 and FSHR was not different between two groups analyzed. The CC genotype for LHR gene was most frequent in animals with EPD SC 365(+), whereas the TT was most frequent in the EPD SC 365(-). For IGF2 the CT and CC were the most frequent genotypes observed in animals with positive and negative EPD SC 365, respectively. The EPD SC 365 was negatively correlated with the EPD AFB (r = 0.23). We suggest that CC and TT genotypes for LHR and IGF2, respectively, could be possible molecular markers for SC selection in Nellore bulls, that can also predict for AFB.

Foram avaliados se polimorfismos de base única (SNPs) presentes nos genes beta-1,4- galactosiltransferase (B4GALT1), receptor de hormônio luteinizante (LHR), receptor de hormônio folículo estimulante (FSHR) e fator de crescimento semelhante à insulina 2 (IGF2) poderiam ser marcadores moleculares para o perímetro escrotal (PE) em touros da raça Nelore. Animais com diferença esperada de progênie positiva (+, n = 104) e negativa (-, n = 74) para PE aos 365 dias (DEP PE 365) foram selecionados e seus SNPs foram analisados utilizando a técnica de polimorfismo de comprimento de fragmentos de restrição (RFLP). A correlação entre DEP PE 365 e idade ao primeiro parto (DEP IPP) também foi investigada. Os SNPs dos genes B4GALT1 e FSHR não apresentaram diferença entre os dois grupos analisados. O genótipo CC para o gene LHR foi mais freqüente em animais com DEP PE 365 (+), enquanto o TT foi mais frequente no grupo com DEP PE 365 (-). Para o gene IGF2, os genótipos CT e CC foram mais freqüentes em animais com DEP PE 365 positiva e negativa, respectivamente. A DEP PE 365 foi negativamente correlacionada com a DEP IPP (r = -0,23). O genótipo CC para o gene LHR e genótipo TT para o gene IGF2 podem ser possíveis marcadores de PE para a seleção assistida em touros da raça Nelore, podendo ser ainda preditores para IPP.

MUC1 VNTR polymorphism is not associated with early puberty in Nelore cattle (Bos primigenius indicus)

MUC1 is a transmembrane glycoprotein expressed in the male and female reproductive tracts, which plays a broad functional role in reproduction. An important feature ofMUC1 is the presence of a VNTR polymorphism in the extracellular domain that is associated with the function of the molecule. In view of its role in reproduction, the aim of the present study was to analyze the effect of the length of the MUC1 VNTR on the early puberty phenotype in Nelore cattle. A total of 230 heifers were studied, including 77 sexually precocious heifers and 153 regular heifers. The genotype was identified by PCR and the allele and genotype frequencies between the two groups (precocious or regular heifers) were compared by Fishers exact test using the population differentiation module of the GenePop program, version 3.4. The associations between VNTR polymorphism and early puberty were analyzed as discrete data using the SAS GenMod procedure of SAS. Higher frequencies were observed for allele 1, 2, and 3, with allele 1 being predominant in both groups. No significant differences in allele or genotype frequencies were observed between precocious and regular heifers. The analyses using ANOVA and orthogonal contrasts suggest that the MUC1 VNTR variation is not associated with early puberty in cattle. Previous studies regarding the MUC1 polymorphism in Nelore cattle suggested that the high frequency of the 1 allele is a characteristic of Brazilian Nelore cattle.(AU)

MUC1 VNTR polymorphism is not associated with early puberty in Nelore cattle (Bos primigenius indicus)

MUC1 is a transmembrane glycoprotein expressed in the male and female reproductive tracts, which plays a broad functional role in reproduction. An important feature ofMUC1 is the presence of a VNTR polymorphism in the extracellular domain that is associated with the function of the molecule. In view of its role in reproduction, the aim of the present study was to analyze the effect of the length of the MUC1 VNTR on the early puberty phenotype in Nelore cattle. A total of 230 heifers were studied, including 77 sexually precocious heifers and 153 regular heifers. The genotype was identified by PCR and the allele and genotype frequencies between the two groups (precocious or regular heifers) were compared by Fisher’s exact test using the population differentiation module of the GenePop program, version 3.4. The associations between VNTR polymorphism and early puberty were analyzed as discrete data using the SAS GenMod procedure of SAS. Higher frequencies were observed for allele 1, 2, and 3, with allele 1 being predominant in both groups. No significant differences in allele or genotype frequencies were observed between precocious and regular heifers. The analyses using ANOVA and orthogonal contrasts suggest that the MUC1 VNTR variation is not associated with early puberty in cattle. Previous studies regarding the MUC1 polymorphism in Nelore cattle suggested that the high frequency of the 1 allele is a characteristic of Brazilian Nelore cattle.