The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)



Gene Review

Mafb  -  v-maf musculoaponeurotic fibrosarcoma...

Mus musculus

Synonyms: Kreisler, Krml, Krml1, Maf-B, Maf1, ...
Welcome! If you are familiar with the subject of this article, you can contribute to this open access knowledge base by deleting incorrect information, restructuring or completely rewriting any text. Read more.

Disease relevance of Mafb


High impact information on Mafb

  • Based on an inversion discovered in the original kr allele, we selected a candidate cDNA highly expressed in the developing caudal hindbrain [3].
  • The mouse kreisler (kr) mutation causes segmentation abnormalities in the caudal hindbrain and defective inner ear development [3].
  • The identity, expression, and mutant phenotype of kr indicate an early role in axial patterning and provide insights into the molecular and embryologic mechanisms that govern hindbrain and otic development [3].
  • This cDNA encodes a basic domain-leucine zipper (bZIP) transcription factor and was confirmed to represent the kr gene by analysis of a second kr allele, generated by chemical mutagenesis, in which a serine is substituted for an asparagine residue conserved in the DNA-binding domain of all known bZIP family members [3].
  • These studies demonstrate that Krml1 directly activates expression of Hoxb-3 in r5 in combination with an Ets-related activation site, and suggest that kreisler plays a primary role in regulating segmental identity through Hox genes [4].

Chemical compound and disease context of Mafb

  • Furthermore, collateral chemosensory pathways that normally mediate delayed responses to hypoxia and hyperoxia were not functional in kr/kr mice [5].

Biological context of Mafb

  • Altered rhombomere-specific gene expression and hyoid bone differentiation in the mouse segmentation mutant, kreisler (kr) [6].
  • This site is necessary for enhancer activity and when multimerized it is sufficient to direct a kreisler-like pattern in transgenic embryos [7].
  • Deletion analysis localized this activity to a 600 bp fragment that was found to contain a single high-affinity binding site for the Maf bZIP protein Krml1, encoded by the kreisler gene [7].
  • We propose that the requirement for the downregulation of segmental kreisler expression prior to neuronal differentiation reflects the stage-specific roles of this gene and its targets [8].
  • In situ hybridization with CRABPI, kreisler and EphA4 probes and the pattern of expression of a Wnt1-lacZ transgene show that neural crest cells (NCC) normally destined to the 3rd and 4th arches migrate ectopically [9].

Anatomical context of Mafb

  • Novel activities of Mafb underlie its dual role in hindbrain segmentation and regional specification [10].
  • kreisler is a recessive mutation resulting in gross malformation of the inner ear of homozygous mice [11].
  • We found that the hyoid bone in kr/kr animals exhibited an accessory process on the greater horn (a third arch structure) most easily explained by ectopic development of a second arch structure (the hyoid lesser horn) in an area normally derived from the third arch [6].
  • To investigate whether the altered patterns of gene expression we observed in the kr/kr embryonic hindbrain are associated with morphologic changes in the adult, we examined neural crest-derived tissues of the second and third branchial arches, which normally arise from rhombomeres 4 and 6, respectively [6].
  • Here we show that mice homozygous for the kr(enu) mutation develop renal disease and that Kreisler is essential for cellular differentiation of podocytes [2].

Associations of Mafb with chemical compounds

  • The hindbrain of E8.5 A alpha/A gamma embryos shows a posterior expansion of rhombomere 3 and 4 (R3 and R4) markers, but fails to express kreisler, a normal marker of R5 and R6 [12].
  • Zkrml2 shows 72% and 92% identity in its basic leucine zipper domain with mouse Krml1 and zebrafish val, respectively [13].

Regulatory relationships of Mafb

  • Examination of Krox-20 expression at stages as early as E8.5 indicates that Krox-20 fails ever to be expressed in its r5 domain in the homozygous kreisler mutant [11].

Other interactions of Mafb

  • The expression domain of Hoxb-1 is affected differently from the other genes in kr/kr embryos; its rostral boundary at r3/4 is intact but the caudal boundary is displaced from its normal location at r4/5 to the approximate position of r5/6 [6].
  • Our work has revealed novel functions for Mafb, including a positive autoregulatory activity, the capacity to repress Hoxb1 expression, and the capacity to synergise with or antagonise Krox20 activity [10].
  • This demonstrates that Hoxa3, along with its paralog Hoxb3, is a direct target of kreisler in the mouse hindbrain [7].
  • Conserved and distinct roles of kreisler in regulation of the paralogous Hoxa3 and Hoxb3 genes [7].
  • Instead of forming a defined r4, Hoxb1- and Wnt8A-expressing cells are scattered throughout the caudal hindbrain, whereas r5/r8 markers such as kreisler or group 3/4 Hox genes are undetectable or markedly downregulated [14].

Analytical, diagnostic and therapeutic context of Mafb


  1. MafB deficiency causes defective respiratory rhythmogenesis and fatal central apnea at birth. Blanchi, B., Kelly, L.M., Viemari, J.C., Lafon, I., Burnet, H., Bévengut, M., Tillmanns, S., Daniel, L., Graf, T., Hilaire, G., Sieweke, M.H. Nat. Neurosci. (2003) [Pubmed]
  2. The mouse Kreisler (Krml1/MafB) segmentation gene is required for differentiation of glomerular visceral epithelial cells. Sadl, V., Jin, F., Yu, J., Cui, S., Holmyard, D., Quaggin, S., Barsh, G., Cordes, S. Dev. Biol. (2002) [Pubmed]
  3. The mouse segmentation gene kr encodes a novel basic domain-leucine zipper transcription factor. Cordes, S.P., Barsh, G.S. Cell (1994) [Pubmed]
  4. Segmental regulation of Hoxb-3 by kreisler. Manzanares, M., Cordes, S., Kwan, C.T., Sham, M.H., Barsh, G.S., Krumlauf, R. Nature (1997) [Pubmed]
  5. Different respiratory control systems are affected in homozygous and heterozygous kreisler mutant mice. Chatonnet, F., del Toro, E.D., Voiculescu, O., Charnay, P., Champagnat, J. Eur. J. Neurosci. (2002) [Pubmed]
  6. Altered rhombomere-specific gene expression and hyoid bone differentiation in the mouse segmentation mutant, kreisler (kr). Frohman, M.A., Martin, G.R., Cordes, S.P., Halamek, L.P., Barsh, G.S. Development (1993) [Pubmed]
  7. Conserved and distinct roles of kreisler in regulation of the paralogous Hoxa3 and Hoxb3 genes. Manzanares, M., Cordes, S., Ariza-McNaughton, L., Sadl, V., Maruthainar, K., Barsh, G., Krumlauf, R. Development (1999) [Pubmed]
  8. Requirement for downregulation of kreisler during late patterning of the hindbrain. Theil, T., Ariza-McNaughton, L., Manzanares, M., Brodie, J., Krumlauf, R., Wilkinson, D.G. Development (2002) [Pubmed]
  9. Retinoid signaling is essential for patterning the endoderm of the third and fourth pharyngeal arches. Wendling, O., Dennefeld, C., Chambon, P., Mark, M. Development (2000) [Pubmed]
  10. Novel activities of Mafb underlie its dual role in hindbrain segmentation and regional specification. Giudicelli, F., Gilardi-Hebenstreit, P., Mechta-Grigoriou, F., Poquet, C., Charnay, P. Dev. Biol. (2003) [Pubmed]
  11. The kreisler mouse: a hindbrain segmentation mutant that lacks two rhombomeres. McKay, I.J., Muchamore, I., Krumlauf, R., Maden, M., Lumsden, A., Lewis, J. Development (1994) [Pubmed]
  12. Roles of retinoic acid receptors in early embryonic morphogenesis and hindbrain patterning. Wendling, O., Ghyselinck, N.B., Chambon, P., Mark, M. Development (2001) [Pubmed]
  13. Expression of Zkrml2, a homologue of the Krml1/val segmentation gene, during embryonic patterning of the zebrafish (Danio rerio). Schvarzstein, M., Kirn, A., Haffter, P., Cordes, S.P. Mech. Dev. (1999) [Pubmed]
  14. Retinoic acid synthesis and hindbrain patterning in the mouse embryo. Niederreither, K., Vermot, J., Schuhbaur, B., Chambon, P., Dollé, P. Development (2000) [Pubmed]
  15. The expression pattern of the mafB/kr gene in birds and mice reveals that the kreisler phenotype does not represent a null mutant. Eichmann, A., Grapin-Botton, A., Kelly, L., Graf, T., Le Douarin, N.M., Sieweke, M. Mech. Dev. (1997) [Pubmed]
WikiGenes - Universities