Role of a conserved retinoic acid response element in rhombomere restriction of Hoxb-1.
After activation in mesoderm and neuroectoderm, expression of the Hoxb-1 gene is progressively restricted to rhombomere (r) 4 in the hindbrain. Analysis of the chick and mouse Hoxb-1 genes identified positive and negative regulatory regions that cooperate to mediate segment-restricted expression during rhombomere formation. An enhancer generates expression extending into r3 and r5, and a repressor limits this domain to r4. The repressor contains a conserved retinoic acid response element, point mutations in which allow expression to spread into adjacent rhombomeres. Retinoids and their nuclear receptors may therefore participate in sharpening segment-restricted expression of Hoxb-1 during rhombomere boundary formation.
Studer
M
M
Lab of Developmental Neurobiology, National Institute for Medical Research, Mill Hill, London, UK.
Pöpperl
H
H
Marshall
H
H
Kuroiwa
A
A
Krumlauf
R
R
D000818:Animals; D001483:Base Sequence; D002642:Chick Embryo; D004742:Enhancer Elements, Genetic; D005786:Gene Expression Regulation; D005801:Genes, Homeobox; D051379:Mice; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D009432:Neural Crest / Q000378:metabolism; D009841:Oligonucleotides / Q000378:metabolism; D017354:Point Mutation; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D018168:Receptors, Retinoic Acid / Q000378:metabolism; D012045:Regulatory Sequences, Nucleic Acid; D047488:Retinoid X Receptors; D012249:Rhombencephalon / Q000196:embryology* / Q000378:metabolism; D014157:Transcription Factors; D014212:Tretinoin / Q000494:pharmacology*
D009841:Oligonucleotides; D018160:Receptors, Cytoplasmic and Nuclear; D018168:Receptors, Retinoic Acid; D047488:Retinoid X Receptors; D014157:Transcription Factors; D014212:Tretinoin