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Temporal expression Expression is maximal between 8-20 h of development.
PMID 11500376

Spatial expression

• Finger: prestalk region [DDANAT:0000016]
• Slug: prestalk [DDANAT:0000019] and posterior region [DDANAT:0000021]
• Mid culminant: stalk [DDANAT:0000039], prestalk A region [DDANAT:0000105]
• Late culminant: expressed everywhere
• Fruting body: upper cup [DDANAT:0000126], lower cup [DDANAT:0000127], inner basal disc [DDANAT:0000051]

PMID 11500376, strain rasC]:lacZ(his) (DBS0237292)

pgaudet August 2006

Gene expression defects in rasC/rasG double null mutants It has been shown previously that rasC- cells do not aggregate, predominantly as a result of a defective cAMP relay Lim et al 2001, although there are also subtle defects in cAMP chemotaxis Wessels, et al 2004. There is no appreciable effect on early gene expression in response to starvation Bolourani et al 2006; Wessels, et al 2004. In contrast, rasG-/rasC- cells are totally blocked in aggregation, cAMP relay and cAMP chemotaxis and, in addition, there is no induction of carA and gpaB gene expression, in response to starvation Bolourani et al 2006. However, expression of carA from the actin15 promoter in vegetative rasG-/rasC- cells restores the induced expression of carA and gpaB in response to starvation, but has no effect on the defects in aggregation, cAMP chemotaxis and cAMP relay Bolourani et al, 2008.

In order to determine the generality of the effect on early gene expression, micro array analysis was undertaken (Parvin Bolourani, Gareth Bloomfield, and Gerry Weeks, unpublished data). Gene expression is greatly perturbed in vegetative rasC-/rasG- double null mutants, and in early development a subset of important signalling genes are not induced adequately. Notable among these early genes are acaA, dagA, erkA, erkB, gpaB, and csbA. The discoidin I genes are also underexpresed. The expression of most of these genes (not the discoidins) is rescued when carA is overexpressed in the double null line. Most remarkably, the overall profile of gene expression changes in vegetative double null mutants compared to the parent strain is highly similar to that of wild-type cells six hours after infection with Legionella pneumophila compared to uninfected cells (in terms of gene expression changes; correlation coefficient = 0.61) Li et al 2009, making this strain phenocopy the Legionella-resistant dupA mutant to some extent (correlation coefficient = 0.49). Of 55 genes overexpressed at least 4-fold in the vegetative rasC-/rasG- double mutant, 53 are at least 2-fold induced six hours after Legionella infection in wild-type AX4 cells (including tirA); 37 of these 55 are overexpressed in uninfected dupA mutants. Further, 44 of the 55 overexpressed genes are developmentally induced in parental cells, and 22 of the 55 show significantly reduced expression upon carA overexpression in vegetative cells.

Array data are available in ArrayExpress under the accession E-TABM-1085.

Gareth Bloomfield November 2010

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