GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com

PMID:19439426

From GONUTS
Jump to: navigation, search
Citation

Dobrowolski, R, Hertig, G, Lechner, H, Wörsdörfer, P, Wulf, V, Dicke, N, Eckert, D, Bauer, R, Schorle, H and Willecke, K (2009) Loss of connexin43-mediated gap junctional coupling in the mesenchyme of limb buds leads to altered expression of morphogens in mice. Hum. Mol. Genet. 18:2899-911

Abstract

Mutations in the GJA1 gene coding for connexin43 (Cx43) cause oculodentodigital dysplasia (ODDD), a pleiotropic human disorder with characteristic morphologic anomalies of face, teeth, bones and digits. Interdigital webbings, also called syndactylies, are a characteristic phenotype of this disease showing high intra- and interfamilial penetrance. Therefore, we decided to study the molecular basis of syndactylies caused by Cx43 mutations. In order to reveal the impact of Cx43-mediated gap junctional coupling, we used mice expressing the human point mutation Cx43G138R and, in addition, 'knock-out' mice lacking Cx43. Both conditional mouse models developed syndactylies as a consequence of disturbed interdigital apoptosis, which we show to be due to reduced expression of two key morphogens: sonic hedgehog (Shh) and bone morphogenic protein 2 (Bmp2). Diminished levels of Bmp2 and subsequent up-regulation of fibroblast growth factors (Fgfs) lead to an insufficient induction of interdigital apoptosis. Interestingly, the reduction of Shh expression in Cx43 mutants begins on embryonic day 10.5 indicating a disturbance of the Fgf/Shh regulatory feedback loop, and confirming the recently published observation that gap junctions can relay Fgf signals to neighboring cells. Thus, Cx43-mediated gap junctional coupling in the mesenchyme of limb buds after ED11 is essential to maintain Shh expression, which regulates the downstream signaling of Bmp2. Besides diminished interdigital apoptosis, the decreased expression of Bmp2 in Cx43 mutants may also be involved in other morphological alterations in patients suffering from ODDD.

Links

PubMed Online version:10.1093/hmg/ddp227

Keywords

Animals; Bone Morphogenetic Protein 2/genetics; Bone Morphogenetic Protein 2/metabolism; Connexin 43/genetics; Connexin 43/metabolism; Disease Models, Animal; Female; Fibroblast Growth Factors/genetics; Fibroblast Growth Factors/metabolism; Gap Junctions/genetics; Gap Junctions/metabolism; Gene Expression Regulation, Developmental; Hedgehog Proteins/genetics; Hedgehog Proteins/metabolism; Humans; Limb Buds/embryology; Limb Buds/metabolism; Male; Mesoderm/metabolism; Mice; Mice, Knockout; Mice, Transgenic; Syndactyly/embryology; Syndactyly/genetics; Syndactyly/metabolism

Significance

Annotations

Gene product Qualifier GO Term Evidence Code with/from Aspect Extension Notes Status

MOUSE:CXA1

acts_upstream_of_or_within

GO:0010628: positive regulation of gene expression

ECO:0000315: mutant phenotype evidence used in manual assertion

MGI:MGI:2445472

P

  • has_input:(MGI:MGI:98297)|has_input:(MGI:MGI:88177)

Seeded From UniProt

complete

MOUSE:CXA1

acts_upstream_of_or_within

GO:0042733: embryonic digit morphogenesis

ECO:0000315: mutant phenotype evidence used in manual assertion

MGI:MGI:2445472

P

Seeded From UniProt

complete

MOUSE:CXA1

acts_upstream_of_or_within

GO:0010629: negative regulation of gene expression

ECO:0000315: mutant phenotype evidence used in manual assertion

MGI:MGI:2445472

P

Seeded From UniProt

complete

MOUSE:CXA1

acts_upstream_of_or_within

GO:0010628: positive regulation of gene expression

ECO:0000315: mutant phenotype evidence used in manual assertion

MGI:MGI:2445472

P

has_regulation_target:(MGI:MGI:98297)|has_regulation_target:(MGI:MGI:88177)

Seeded From UniProt

complete

MOUSE:CXA1

acts_upstream_of_or_within

GO:0042733: embryonic digit morphogenesis

ECO:0000315: mutant phenotype evidence used in manual assertion

MGI:MGI:2445472

P

has_participant:(EMAPA:17428)

Seeded From UniProt

complete


See also

References

See Help:References for how to manage references in GONUTS.