Goat SRY induces testis development in XX transgenic mice.

The testis-determining gene SRY is not well-conserved among mammals, particularly between mouse and other mammals, both in terms of protein structure and of expression regulation. To evaluate SRY phylogenic conservation in regards to its function, we expressed the goat gene (gSRY) in XX transgenic mouse gonads. Here, we show that gSRY induces testis formation, despite a goat expression profile.

Heterogeneous inducible mammary-specific expression of Jab/SOCS1 in lactating transgenic mice is associated with no obvious phenotype, even at the cellular level.

The cytokine-inducible suppressor of cytokine signalling SOCS1, or JAB, has been shown to be implicated in vitro in the negative regulation of the prolactin-receptor-induced activation of JAK2 and STAT5. Disruption of this gene in vivo resulted in an accelerated mammary gland development. In the present experiment, we assessed the potential impact on the lactation process of the doxycycline-inducible mammary-controlled expression of this gene in transgenic mice.

Substitution of the alpha-lactalbumin transcription unit by a CAT cDNA within a BAC clone silenced the locus in transgenic mice without affecting the physically linked Cyclin T1 gene.

We recently reported that a goat bacterial artificial chromosome (BAC) clone conferred site-independent expression in transgenic mice of the two loci present within its insert, the ubiquitously expressed Cyclin T1 and the mammary specific alpha-lactalbumin (alphalac) genes. To assess if this vector could target mammary-restricted expression of cDNA, the CAT ORF was introduced by homologous recombination in Escherichia coli in place of the alphalac transcription unit. The insert of this modified BAC was injected into mice and three transgenic lines were derived.