POU homeodomain genes and myogenesis.
We show that members of the POU homeodomain family are among the transcription factors expressed in developing mouse skeletal muscle. From a cDNA library prepared from fetal muscle mRNA, we cloned a cDNA identical to that of Brn-4, a POU class II gene previously cloned from neural tissues. In limb muscle, we found that Brn-4 mRNA expression was highest at embryonic days 15-18, declined-after birth, and was undetectable in adults. The mRNAs of two additional POU genes, Emb (POU class VI) and Oct-1 (POU class II), were also expressed in developing muscle and, unlike Brn-4, continued to be expressed in postnatal and adult muscles. In skeletal muscle, expression of Brn-4 is myogenin-dependent, because muscles from myogenin-deficient fetuses contained much less Brn-4 mRNA than muscles from myogenin-expressing littermates. In contrast, expression of Emb was the same in the presence or absence of myogenin. The distinct pattern of Brn-4 mRNA expression and its dependence on a myogenic regulatory factor suggest that Brn-4 is part of the network of interacting transcription factors that control muscle-specific gene expression during mammalian myogenesis.
Neuromuscular Laboratory, Massachusetts General Hospital, Charlestown 02129, USA.
J A
JA
Dominov
J B
JB
Miller
D016475:3T3 Cells; D000818:Animals; D002478:Cells, Cultured; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D005121:Extremities / Q000196:embryology; D018507:Gene Expression Regulation, Developmental; D005801:Genes, Homeobox; D005838:Genotype; D018398:Homeodomain Proteins / Q000096:biosynthesis / Q000145:classification / Q000235:genetics / Q000502:physiology*; D051863:Host Cell Factor C1; D051379:Mice; D008809:Mice, Inbred C3H; D018345:Mice, Knockout; D008817:Mice, Mutant Strains; D005810:Multigene Family; D009121:Muscle Denervation; D009124:Muscle Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D018482:Muscle, Skeletal / Q000196:embryology* / Q000378:metabolism / Q000502:physiology; D018008:Myogenin / Q000235:genetics / Q000502:physiology*; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D050811:Octamer Transcription Factor-1; D009928:Organ Specificity; D050809:POU Domain Factors; D012333:RNA, Messenger / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D012038:Regeneration; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D014162:Transfection
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C497693:Hcfc1 protein, mouse; D018398:Homeodomain Proteins; D051863:Host Cell Factor C1; D009124:Muscle Proteins; C503801:Myog protein, mouse; D018008:Myogenin; D009419:Nerve Tissue Proteins; D050811:Octamer Transcription Factor-1; D050809:POU Domain Factors; C494166:Pou2f1 protein, mouse; C484088:Pou3f4 protein, rat; C489996:Pou6f1 protein, mouse; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; C074067:Pou3f4 protein, mouse