RESUMO
We report the cloning and expression during limb development of the chicken Slit1, Slit2, and Slit3 ligands, and Robo1 and Robo2 receptor genes. We also compare the expression patterns of Robo1 and Robo2 in developing chick and mouse hindlimbs. These genes are expressed in regions of muscle development, chrondrogenesis, and axon guidance.
Assuntos
Extremidades/embriologia , Expressão Gênica , Proteínas de Membrana/genética , Proteínas do Tecido Nervoso/genética , Receptores Imunológicos/genética , Animais , Embrião de Galinha , Perfilação da Expressão Gênica , Membro Posterior/embriologia , Hibridização In Situ , Peptídeos e Proteínas de Sinalização Intercelular , Mesoderma/metabolismo , Camundongos , Dados de Sequência Molecular , Ratos , Proteínas RoundaboutRESUMO
Homozygous targeted disruption of the mouse Caspase 8 (Casp8) gene was found to be lethal in utero. The Caspase 8 null embryos exhibited impaired heart muscle development and congested accumulation of erythrocytes. Recovery of hematopoietic colony-forming cells from the embryos was very low. In fibroblast strains derived from these embryos, the TNF receptors, Fas/Apo1, and DR3 were able to activate the Jun N-terminal kinase and to trigger IkappaB alpha phosphorylation and degradation. They failed, however, to induce cell death, while doing so effectively in wild-type fibroblasts. These findings indicate that Caspase 8 plays a necessary and nonredundant role in death induction by several receptors of the TNF/NGF family and serves a vital role in embryonal development.
Assuntos
Caspases , Cisteína Endopeptidases/genética , Cisteína Endopeptidases/fisiologia , Fibroblastos/citologia , Marcação de Genes , Genes Letais/genética , Receptores do Fator de Necrose Tumoral/fisiologia , Receptor fas/fisiologia , Animais , Caspase 8 , Caspase 9 , Morte Celular/efeitos dos fármacos , Morte Celular/genética , Células Cultivadas/efeitos dos fármacos , DNA Complementar/genética , Morte Fetal/genética , Fibroblastos/efeitos dos fármacos , Fibroblastos/fisiologia , Idade Gestacional , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout/embriologia , Fenótipo , Membro 25 de Receptores de Fatores de Necrose Tumoral , Transcrição Gênica/genética , Receptor fas/farmacologiaRESUMO
A transgenic mouse strain with early and uniform expression of the Cre site-specific recombinase is described. In this strain, PGK-Crem, Cre is driven by the early acting PGK-1 promoter, but, probably due to cis effects at the integration site, the recombinase is under dominant maternal control. When Cre is transmitted by PGK-Crem females mated to males that carry a reporter transgene flanked by loxP sites, even offspring that do not inherit PGK-Cre delete the target gene. It follows that in the PGK-Crem female Cre activity commences in the diploid phase of oogenesis. In PGK-Crem crosses complete recombination was observed in all organs, including testis and ovary. We prepared a mouse stock that is homozygous for PGK-Crem and at the albino (c) locus. This strain will be useful for the early and uniform induction of ectopic and dominant negative mutations, for the in vivo removal of selective elements from targeted mutations and in connection with the manipulation of targeted loci in 'knock in' and related technologies.