Polimorfismos del gen ob en bovinos de raza holstein en la Comarca Lagunera, México

The Laguna Region is the most important dairy region of Mexico. Currently are using various techniques to genetically evaluate the animal at an early age, allowing to select future breeding with desirable characteristics. Among related genes to milk production, are the Ob gene also called Leptin gene which acts on the central nervous system and peripheral tissues playing an important role in regulating modulation of appetite, body weight gain, increased metabolism energy and muscle anabolism. This study was performed to determine polymorphism restriction fragment length ACI I of Leptin gene in exon 2 and correlate it with the production parameters and milk quality. Blood sample of one hundred cows were collected on the dairy farm "Lacteos Florida" Francisco I. Madero municipality of Coahuila, Mexico with three status of milk production: high, medium and low. DNA extraction was performed by the modified method of Salting-Out. PCR of leptin gene was performed resulting in a fragment of 272 bp in length and was subjected to PCR-RFLP with the ACI I restriction enzyme and sequencing, correlating TT, CT and CC genotypes with groups of cows sampled high, medium, low producers respectively. Statistical analysis indicated that cows carrier the homozygous genotype (TT) have a significant effect (P <0.01) with respect to the characteristics of production and quality of milk since they had a higher feed intake, weight gain, and a high milk production compared to heterozygote (CT) and homozygote (CC) genotypes. The results show that molecular identification of Ob gene polymorphisms can be used as a tool for genetic selection in Holstein cattle.