Real-time imaging of Leishmania mexicana-infected early phagosomes: a study using primary macrophages generated from green fluorescent protein-Rab5 transgenic mice.

The small GTPase Rab5 is a key regulator of endosome/phagosome maturation and in intravesicular infections marks a phagosome stage at which decisions over pathogen replication or destruction are integrated. It is currently unclear whether Leishmania-infected phagosomes uniformly pass through a Rab5(+) stage on their intracellular path to compartments with late endosomal/early lysosomal characteristics. Differences in routes and final compartments could have consequences for accessibility to antileishmanial drugs.

Manipulating the mouse genome to engineer precise functional syntenic replacements with human sequence.

We have devised a strategy (called recombinase-mediated genomic replacement, RMGR) to allow the replacement of large segments (>100 kb) of the mouse genome with the equivalent human syntenic region. The technique involves modifying a mouse ES cell chromosome and a human BAC by inserting heterotypic lox sites to flank the proposed exchange interval and then using Cre recombinase to achieve segmental exchange. We have demonstrated the feasibility of this approach by replacing the mouse alpha globin regulatory domain with the human syntenic region and generating homozygous mice that produce only human alpha globin chains.

Cre-loxP chromosome engineering of a targeted deletion in the mouse corresponding to the 3p21.3 region of homozygous loss in human tumours.

Chromosomal deletions are a common feature of epithelial tumours and when further defined by homozygous deletions, are often the location of tumour suppressor genes. Deletions within the short arm of chromosome 3 occur very frequently in human carcinomas: a minimal region of loss at 3p21.3 (the Luca) region has been defined by overlapping homozygous deletions in lung and breast cancer cell lines.