Somatic gene transfer into the lactating ovine mammary gland

Abstract

The ovine mammary gland turned out to be a very well suited as a model system for evaluation and optimization of various gene transfer protocols.

Transgenic Modification of Production Traits in Farm Animals

“…Second, in addition to germ line integration of transgenes, somatic gene-transfer approaches result in (mostly transient) gene expression with the longest duration being a life span and no transmission of the transgenes to the progeny. Although somatic gene-transfer experiments in farm animals have been performed for production purposes [5,6] this technology in animal production is more beneficial for the development of DNA-based vaccines [7]. Here we will mainly concentrate the discussion on germ line transgenic animals.…”

Adeno-associated-virus-mediated transduction of the mammary gland enables sustained production of recombinant proteins in milk

“…Somatic gene transfer by in vivo transfection of the mammary gland with lipofection and electroporation following transductal delivery of vectors has been demonstrated but it achieves only poor levels of transient expression 8 . Somatic gene transfer using retroviruses (Gibbon ape leukemia virus/Moloney murine leukemia virus hybrid retrovirus) has also been assessed for the expression of human growth hormone in the goat mammary gland 9 .…”

Modelos para a produção de eritropoietina recombinante humana in vivo e in vitro com vetores plasmideais em ovinos

“…Os promotores não apresentam total eficiência no direcionamento da expressão gênica para o tecido alvo, podendo apresentar efeito negativo no metabolismo dos animais transgênicos. Como alternativa da transgenia, diversos grupos de pesquisa estão tentando desenvolver um sistema de expressão protéica em glândula mamária baseado na transferência de genes para o epitélio glandular in situ, sendo necessário o estudo de vários sistemas de produção como o complexo de poli-íons (HENZ et al, 2000), o receptor para mediação de endocitose (SOBOLEV et al, 1998), o injetor de genes (KERR et al, 1996), a eletroporação (DÜCHLER et al, 2002) e os vetores virais (ARCHER et al, 1994;YANG et al, 1995). Embora ocorra a produção da proteína de interesse ela ocorre em baixa quantidade, com alto custo e com resultados variáveis.…”