Ubiquitous expression of goat cyclin T1 in transgenic mice.

Ubiquitous gene expression has a variety of applications in transgenesis that include, for example cell lineage analyses in chimeras and gain-of-function related to xenotransplantations. Although several promoters have already been used to these aims, they often do not reliably or reproducibly target gene expression in mice. We have recently reported the site-independent expression of a bacterial artificial chromosome (BAC)-derived goat alpha-lactalbumin transgene in the mammary gland of mice and the subsequent localisation within the insert of this BAC of the cyclin T1 locus. This ubiquitously expressed gene encodes for a protein that acts as a co-factor for the HIV nuclear transcriptional activator. In the present paper, we report that the goat BAC transgene, which encompasses around 30 kb of the cyclin T1 promoter, also confers ubiquitous expression of this gene in the six transgenic mouse lines analysed. These results suggest that the cyclin T1 promoter could be a useful alternative to target ubiquitous gene expression in transgenics.