RESUMO
In mouse, XY embryos are committed to the male sex determination pathway after the transient expression of the Y-linked Sry gene in the Sertoli cell lineage between 10.5 and 12.5 dpc. In the C57BL/6J strain, male sex determination program can be modulated by some autosomal genes. The C57BL/6J alleles at these autosomal loci can antagonize male sex determination in combination with specific Sry alleles. In this report, the authors have identified an effect of these C57BL/6J specific alleles in combination with a mutated Sox9 allele, Sox9(Ods). Authors report the mapping of three of these genetic loci on mouse chromosome 5 and 10 in a backcross of the Ods mutation to the C57BL/6J background. Our study confirms the importance of the strain C57BL/6J for the investigation of the genetic mechanisms that control sex determination.
Assuntos
Processos de Determinação Sexual , Cromossomo X/genética , Animais , Feminino , Proteínas de Grupo de Alta Mobilidade/genética , Masculino , Camundongos , Camundongos Endogâmicos AKR , Camundongos Endogâmicos C57BL , Fatores de Transcrição SOX9 , Fatores de Transcrição/genética , Cromossomo Y/genéticaRESUMO
A significant barrier to exploiting the full potential of the rat as a biomedical model is the lack of tools to easily modify its germline. Here we show that a tyrosinase-tagged Sleeping Beauty transposon can be used as a simple, efficient method to generate rat mutants in vivo. By making two lines of transgenic rats, one carrying the transposon and another expressing the transposase in germ cells, we are able to obtain bigenic males in which transposition occurs in the germ cells. We show that transposition leads to the appearance of new coat colors in the offspring. Using such bigenic males, we obtained an average of 1.2 transpositions per gamete and identified 19 intragenic integration events among 96 transposition sites that were sequenced. In addition, gene trapping was confirmed and rats with evidence for transposon-induced dominant ocular anomalies were identified. These data suggest that the modified Sleeping Beauty transposon represents a powerful new tool for producing molecularly defined mutagenesis in the rat.