Dr. Leon W. Browder

B.A. University of Colorado, 1962

M.S. Louisiana State University, 1964

Ph.D. Zoology, University of Minnesota, 1967

Professor, Department of Biological Sciences

Phone: (403) 220-6787



My research is focused on the study of mechanisms that control protein
synthesis during oogenesis and early embryonic development of Xenopus
laevis, the South African Clawed Frog. This organism has served as a
paradigm for vertebrate development since the early 1970's and has
played a major role in most of the significant discoveries in
developmental biology for the last two decades. Early Xenopus
development is characterized by rapid cell division and intercellular
signalling events that are necessary in establishing cell fates. In
somatic cells, both of these functions are regulated extensively by
oncoproteins and growth factors. Although most of our understanding of
the functions of these growth-related proteins comes from studies with
cancer cells, we are now gaining an appreciation for the role that these
growth-related proteins play during development.

Protein synthesis in early post-fertilization Xenopus development
depends entirely upon translation of mRNAs that are synthesized during
oogenesis and stored for utilization during early development. We are
examining the mechanisms involved in regulating the synthesis of
growth-related proteins during this critical phase of development. These
experiments have led to the discovery that double-stranded regions of
RNA molecules can serve as signals for developmental regulation of
transcript utilization. Transcripts encoding oncoproteins, growth
factors, and growth factor receptors typically have the potential to
form double-stranded regions in their 5' untranslated regions. Thus, we
are exploring the role that developmentally regulated unwinding of
double-stranded RNA plays in regulating the synthesis of these critical
proteins. Because of the involvement of growth-related transcripts in
both development and cancer, mechanisms that regulate their utilization
in development may also be relevant to regulating growth control in
somatic cells of the adult and, therefore, relevant to the understanding
of the aberrant growth control that characterize cancer cells.



Gibson, A.W., R. Ye, R.N. Johnston, and L.W. Browder. 1992. A
possible role for c-MYC oncoproteins in posttranscriptional
regulation of ribosomal RNA. Oncogene 7: 2363-2367.

Browder, L.W., J. Wilkes, and D.I. Rodenhiser. 1992. Preparative
labelling of proteins with [35S] methionine. Analyt. Biochem. 204:

Gibson, A.W., R. Ye, R.N. Johnston, and L.W. Browder. 1992. Multiple
antigens recognized by anti-c-myc antibodies in human cells and
Xenopus oocytes. Biochem. Cell Biol. 70: 998 - 1005.

Marsden, M., R.W. Nickells, M. Kapoor, and L.W. Browder. 1993. The
induction of pyruvate kinase synthesis by heat shock in Xenopus
laevis embryos. Develop. Genetics 14: 51-57.

Browder, L.W. 1996. Gene expression, cell determination and differentiation. In Textbook of Tissue Engineering, edited by R. Lanza, R. Langer, and W. Chick. R.G. Landes, Austin, Texas. In press.

Fraser, S.D., J. Wilkes-Johnston, and L.W. Browder. 1996. Effects of c-myc first exons and 5' synthetic hairpins on RNA translation in oocytes and early embryos of Xenopus laevis. Oncogene. In press.


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