Title of article :
Characterization and polymorphism screening of IGF-I and prolactin genes in Nelore heifers
Author/Authors :
Monyka Marianna Massolini Laureano، نويسنده , , Antonio Roberto Otaviano، نويسنده , , Andre Luis Ferreira Lima، نويسنده , , Raphael Bermal Costa، نويسنده , , Ana Karina Dias Salman، نويسنده , , Janete Apparecida Desiderio Sena، نويسنده , , Humberto Tonhati، نويسنده , , Lucia Galvao de Albuquerque، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2009
Pages :
7
From page :
277
To page :
283
Abstract :
Insulin growth factor I (IGF-I) and prolactin (PRL) are peptide hormones that exert complementary effects on reproductive traits by acting on folliculogenesis. In view of the lack of information about the IGF-I and PRL genes in Bos indicus, the objective of this study was to partially characterize the promoter regions of these genes and to screen animals of different ages at first pregnancy for the presence of polymorphisms in these regions. In addition, we determined whether polymorphisms influence the regulation of the two hormone genes, evaluating their association with sexual precocity.The animals were divided into three groups according to age at first pregnancy: 1) 100 heifers considered to be sexually precocious that became pregnant at 15-16 months of age, 2) 100 heifers that became pregnant during the normal breeding season at 24 months of age, and 3) 100 heifers that did not become pregnant until 24 months of age. For the IGF-I gene, PCR-RFLP-SnaBI analysis showed the presence of genotypes AB and BB at frequencies of 0.02 and 0.98, respectively. Sequencing of the IGF-I gene fragment revealed a single nitrogen base change from cytosine to thymine, corresponding to the restriction site of SnaBI. The polymorphisms identified in the 5ʹ-flanking region of the IGF-I gene may serve as a ba-sis for future studies of molecular markers in cattle. For the PRL gene, PCR-RFLP-HaeIII analysis showed the presence of only one migration pattern, a finding characterizing the region studied as monomorphic. The study of other regions in the IGF-I and PRL genes might provide molecular data that can be used in the future for the selection of sexually precocious animals.
Keywords :
beef cattle , RFLP , Sexual precocity , molecular marker
Journal title :
Italian Journal of Animal Science
Serial Year :
2009
Journal title :
Italian Journal of Animal Science
Record number :
671587
Link To Document :
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