Production of transgenic bovine by homologous recombination: a technical approach

• Grant number: 03/10167-8
• Support Opportunities: PRONEX Research - Thematic Grants
• Duration: July 01, 2004 - July 31, 2008
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Convênio/Acordo: CNPq - Pronex
• Principal Investigator: José Antonio Visintin
• Grantee: José Antonio Visintin
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Pesquisadores principais: Flávio Vieira Meirelles ; José Buratini Junior ; Luiz Lehmann Coutinho

Abstract

The cattle breeding sector corresponds to more than half of the agribusiness production in developed countries and more than one quarter in developing countries. Actually, this sector tries to increase the efficiency on production characters, like weight gain. Several studies describe the myostatin such as a negative regulator of skeletal muscle growing. On this hand, mutations that inactive its actions can result on the double musculature phenotype were just described in some cattle bred. The reproduction of this phenotype in laboratory, resulting in animals without functional myostatin formation by knock-out of those genes and following increasing of the size and number of muscle fibers, was described in mice. This fact allows the exploration of those characteristics by genetic manipulation to produce animals that present this characteristic and that are able to transmit it to their progenies. In those circumstances, this study proposes to make transgenic; bovines that present a blockage on functional myostatin formation. In order to do it, fibroblasts from Bos promigenius indicus (Nelore) will be-genetically manipulated to obtain cells with the myostatin gene knocked out by homologue recombination that will be used to cloning by nuclear transfer. The embryos deriving from cloning will be transferred to Bos indicus recipients and after birth the animal and its placenta will be analyzed in order to determine the transgenic effect after cloning in cattle. (AU)