TY  - GEN
T1  - The MLK-1/SCD-4 Mixed Lineage Kinase/MAP3K functions to promote dauer formation upstream of DAF-2/InsR
AU  - Rasmussen, Neal R
AU  - Smith, Harold E
AU  - Reiner, David J
DO  - 10.17912/micropub.biology.000405
UR  - http://beta.micropublication.org/journals/biology/micropub-biology-000405/
AB  - The C. elegans dauer is an alternative L3 stage larva that forms under harsh environmental conditions, including low food, high temperature, and high concentration of constitutively secreted dauer pheromone. Genetic screens identified genes conferring dauer-constitutive and dauer-defective phenotypes (Daf-c and Daf-d, respectively; Hu, 2007). Double mutant analysis using principles of epistasis and parallelism ordered genes controlling the dauer process into a network (Gottlieb and Ruvkun, 1994; Thomas et al., 1993). Molecular genetic cloning of genes provided identities with similarity to orthologs in Drosophila and mammals. Taken together, these approaches arrived at a model of four main signaling axes controlling entry into dauer: upstream and parallel TGF-beta (DAF-7, mutated to Daf-c) and receptor guanylyl cyclase (DAF-11, mutated to Daf-c) signals reflect parallel processing by sensory neurons, revealed by laser ablation experiments (Birnby et al., 2000; Ren et al., 1996; Schackwitz et al., 1996). Downstream, serial Insulin/IGF-like growth factor receptor (DAF-2, mutated to Daf-c; (Kimura et al., 1997) and nuclear hormone receptor (DAF-12/NHR, mutated to Daf-d; (Antebi et al., 2000) signals control and execute tissue-specific changes in the animal (Fig. 1C, DAF-12 not shown). Mutants for each signaling axis also control diverse developmental and metabolic outputs in addition to the dauer decision. The four-axis model of signaling control of dauer formation neglects potential positive- and negative-feedback loops and is thus likely reductive. Still, these approaches have provided a robust framework for further investigation into the control of the dauer developmental decision by sensory and endocrine signaling modalities.
PY  - 2021
JO  - microPublication Biology
ER  -