Multiple processes are influenced by a protein family named the function of Mitogen Activated Protein Kinases (MAPK), where among tissue morphogenesis, cell-proliferation, cell-differentiation,... Show moreMultiple processes are influenced by a protein family named the function of Mitogen Activated Protein Kinases (MAPK), where among tissue morphogenesis, cell-proliferation, cell-differentiation, cell-survival and immune reactions. A consequence of this broad role of these proteins is that disturbed MAPK signaling possibly leads to severe affects, and could even lead to the development of a disease or disturb embryogenesis. The human genome encodes for 14 mapk genes. One of the best characterized MAPK signaling transductions pathways is the Extracellular signal Regulated Kinase 1 and 2 (ERK1/ERK2). The zebrafish is a relatively new, genetic accessible model organism, which is because of their transparency of the embryos, very suitable to study the role of the MAPKs in embryonic development. The study described in this thesis shows that the zebrafish genome encodes for the same mapk genes, which makes it possible to study the functions of these proteins, using the zebrafish. Further investigations to the roles of ERK1 and ERK2 during embryonic development led to the new insight that ERK1 and ERK2 have distinct roles during crucial developmental cell migration processes and the differentiation of tissues and cell types. In addition, it was found that ERK1 and ERK2 affect the expression of common as well as distinct target genes. Show less
