Dominique Alfandari, veterinary and animal sciences, recently received a four-year, $1 million National Institutes of Health (NIH) grant to produce and characterize monoclonal antibodies to proteins in a species of frog, Xenopus, used as a model system for developmental biology and human diseases.
Alfandari and colleagues, including co-investigator Hélène Cousin, are internationally known for tracking individual cells in frog embryos to learn how various proteases control proteins in the embryo’s cranial neural crest to form the jaw and face. Cranial neural crest cell migration is common to all vertebrate embryos including humans, and defects in their production or migration lead to severe facial malformations.
As the developmental biologist explains, the amphibian embryo, and in particular the frog Xenopus laevis, is an outstanding model used by embryologistsand cell biologists worldwide to study cranio-facial development in the early embryo. This model system has led to the discovery of axis formation, tissue induction and nuclear reprograming and more. As an embryo forms, its overall body pattern is determined by the formation of three clear axes: the head-tail or anterior-posterior axis, the back-belly or dorsal-ventral axis and left-right asymmetry.
Alfandari adds, “Advances in genome sequencing, proteomics and gene silencing have rejuvenated this model. Because we now know the full genome of Xenopus, we can identify human homologues, and produce mutations in the frog that are believed tocause human disease. This allows researchers to determine rapidly if a single gene mutation is sufficient to cause the disease. In addition, it may help identify ways to correct the defect or find drugs that could bypass the defective gene since thousands of embryos can be generated and tested with drug libraries.
He also points out that recently the Xenopus research community has identified a lack of adequate sources of antibody for studying Xenopus proteins and identified producing more such protein sources as a research priority. With the new grant, Alfandari and colleagues will address this need.
He says, “We plan to produce at least 100 fully characterized monoclonal antibodies to transcription factors, cell surface proteins including signaling receptors and ligands, as well as tissue-specific markers as new tools to be freely shared around the world with the Xenopus research community.”
A steering committee of Xenopus investigators will help to select the project’s protein targets, based on the importance of the proteins in developmental and diseases processes and the absence of cross-reactive commercial antibodies.
Alfandari and colleagues say that “from these immunizations we will produce and archive more than 10,000 clonal IgG-expressing hyrbidomas that will be screened by immunofluorescence, whole-mount immunostaining and immunoprecipitation to identify monoclonal antibodies to native proteins.”