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Genetics of phototaxis in a model eukaryote, Dictyostelium discoideum
Author(s) -
Fisher Paul R.
Publication year - 1997
Publication title -
bioessays
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.175
H-Index - 184
eISSN - 1521-1878
pISSN - 0265-9247
DOI - 10.1002/bies.950190507
Subject(s) - dictyostelium discoideum , biology , slug , eukaryote , dictyostelium , phototaxis , multicellular organism , morphogenesis , microbiology and biotechnology , signal transduction , second messenger system , transduction (biophysics) , gene , slime mold , genetics , biochemistry , genome , ecology
The life cycle of Dictyostelium discoideum offers a unique opportunity to study signal transduction in eukaryotic cells at both the unicellular and multicellular levels of organization. Adding to the already extensive knowledge of the unicellular stages, classical and molecular genetics have begun to unravel transduction of signals controlling morphogenesis and behaviour (phototaxis and thermotaxis) in the multicellular ‘slug’ stage of the life cycle. Distributed over all seven genetic linkage groups are probably about 20, but possibly as many as 55, genes of importance for slug behaviour. The encoded proteins appear from pharmacological studies and mutant phenotypes to govern transduction pathways involving the intracellular second messengers cyclic AMP, cyclic GMP, IP 3 and Ca 2+ . Pathways from the photo‐ and thermoreceptors converge first with each other and thence, at the level of the second messengers, with those from extracellular tip activation (cyclic AMP) and inhibition (Slug Turning Factor and/or ammonia and/or adenosine) signals that control slug movement and morphogenesis.