Developmental functions of theDistal-less/Dlx homeobox genes

Development ◽  
2002 ◽  
Vol 129 (19) ◽  
pp. 4371-4386 ◽  
Author(s):  
Grace Panganiban ◽  
John L. R. Rubenstein
Keyword(s):  
Transcription Factor ◽  
Recent Work ◽  
Phylogenetic Relationships ◽  
Limb Development ◽  
Axis Formation ◽  
Animal Kingdom ◽  
Developmental Processes ◽  
Homeodomain Transcription Factor ◽  
Appendage Development ◽  
Dlx Genes

Distal-less is the earliest known gene specifically expressed in developing insect limbs; its expression is maintained throughout limb development. The homeodomain transcription factor encoded by Distal-less is required for the elaboration of proximodistal pattern elements in Drosophila limbs and can initiate proximodistal axis formation when expressed ectopically. Distal-less homologs, the Dlx genes, are expressed in developing appendages in at least six phyla, including chordates, consistent with requirements for Dlx function in normal appendage development across the animal kingdom. Recent work implicates the Dlx genes of vertebrates in a variety of other developmental processes ranging from neurogenesis to hematopoiesis. We review what is known about the invertebrate and vertebrate Dll/Dlx genes and their varied roles during development. We propose revising the vertebrate nomenclature to reflect phylogenetic relationships among the Dlx genes.

Novel regulatory interactions revealed by studies of murine limb pattern in Wnt-7a and En-1 mutants

Development ◽  
1997 ◽  
Vol 124 (24) ◽  
pp. 5021-5032 ◽  
Author(s):  
J.A. Cygan ◽  
R.L. Johnson ◽  
A.P. McMahon
Keyword(s):  
Transcription Factor ◽  
Limb Development ◽  
Ectopic Expression ◽  
Primary Role ◽  
Distal Limb ◽  
Homeodomain Transcription Factor ◽  
Genetic Mechanisms ◽  
Dorsal Ectoderm ◽  
Limb Pattern ◽  
The Relationship

Classical embryological experiments have demonstrated that dorsal-ventral patterning of the vertebrate limb is dependent upon ectodermal signals. One such factor is Wnt-7a, a member of the Wnt family of secreted proteins, which is expressed in the dorsal ectoderm. Loss of Wnt-7a results in the appearance of ventral characteristics in the dorsal half of the distal limb. Conversely, En-1, a homeodomain transcription factor, is expressed exclusively in the ventral ectoderm, where it represses Wnt-7a. En-1 mutants have dorsal characteristics in the ventral half of the distal limb. Experiments in the chick suggest that the dorsalizing activity of Wnt-7a in the mesenchyme is mediated through the regulation of the LIM-homeodomain transcription factor Lmx-1. Here we have examined the relationship between Wnt-7a, En-1 and Lmx-1b, a mouse homolog of chick Lmx-1, in patterning the mammalian limb. We find that Wnt-7a is required for Lmx-1b expression in distal limb mesenchyme, and that Lmx-1b activation in the ventral mesenchyme of En-1 mutants requires Wnt-7a. Consistent with Lmx-1b playing a primary role in dorsalization of the limb, we find a direct correlation between regions of the anterior distal limb in which Lmx-lb is misregulated during limb development and the localization of dorsal-ventral patterning defects in Wnt-7a and En-1 mutant adults. Thus, ectopic Wnt-7a expression and Lmx-1b activation underlie the dorsalized En-1 phenotype, although our analysis also reveals a Wnt-7a-independent activity for En-1 in the repression of pigmentation in the ventral epidermis. Finally, we demonstrate that ectopic expression of Wnt-7a in the ventral limb ectoderm of En-1 mutants results in the formation of a second, ventral apical ectodermal ridge (AER) at the junction between Wnt-7a-expressing and nonexpressing ectoderm. Unlike the normal AER, ectopic AER formation is dependent upon Wnt-7a activity, indicating that distinct genetic mechanisms may be involved in primary and secondary AER formation.

scholarly journals A crucial role for the homeodomain transcription factor Hhex in lymphopoiesis

Blood ◽  
2015 ◽  
Vol 125 (5) ◽  
pp. 803-814 ◽  
Author(s):  
Jacob T. Jackson ◽  
Chayanica Nasa ◽  
Wei Shi ◽  
Nicholas D. Huntington ◽  
Clifford W. Bogue ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Crucial Role ◽  
Homeodomain Transcription Factor ◽  
Key Points

Key Points Hhex regulates development of diverse lymphoid lineages. Hhex regulates cycling of lymphoid precursors.

scholarly journals The PDX1 Homeodomain Transcription Factor Negatively Regulates the Pancreatic Ductal Cell-specific Keratin 19 Promoter

2006 ◽  
Vol 281 (50) ◽  
pp. 38385-38395 ◽  
Author(s):  
Therese B. Deramaudt ◽  
Mira M. Sachdeva ◽  
Melanie P. Wescott ◽  
Yuting Chen ◽  
Doris A. Stoffers ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Homeodomain Transcription Factor ◽  
Keratin 19 ◽  
Ductal Cell ◽  
Pancreatic Ductal Cell

Identification of a nuclear localization signal, RRMKWKK, in the homeodomain transcription factor PDX-1

FEBS Letters ◽  
1999 ◽  
Vol 461 (3) ◽  
pp. 229-234 ◽  
Author(s):  
Tilo Moede ◽  
Barbara Leibiger ◽  
Hamedeh Ghanaat Pour ◽  
Per-Olof Berggren ◽  
Ingo B Leibiger
Keyword(s):  
Transcription Factor ◽  
Nuclear Localization ◽  
Nuclear Localization Signal ◽  
Homeodomain Transcription Factor ◽  
Localization Signal

scholarly journals The Repo Homeodomain Transcription Factor Suppresses Hematopoiesis in Drosophila and Preserves the Glial Fate

2018 ◽  
Vol 39 (2) ◽  
pp. 238-255 ◽  
Author(s):  
Guillaume Trébuchet ◽  
Pierre B. Cattenoz ◽  
János Zsámboki ◽  
David Mazaud ◽  
Daria E. Siekhaus ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Homeodomain Transcription Factor ◽  
Glial Fate

Conservation of Pitx1 expression during amphibian limb morphogenesis

2006 ◽  
Vol 84 (2) ◽  
pp. 257-262 ◽  
Author(s):  
W Y Chang ◽  
F KhosrowShahian ◽  
M Wolanski ◽  
R Marshall ◽  
W McCormick ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Xenopus Laevis ◽  
Expression Patterns ◽  
Limb Bud ◽  
Eleutherodactylus Coqui ◽  
Limb Buds ◽  
Homeodomain Transcription Factor ◽  
Limb Morphogenesis ◽  
Pelvic Limb

In contrast to the pattern of limb emergence in mammals, chicks, and the newt N. viridescens, embryos such as Xenopus laevis and Eleutherodactylus coqui initiate pelvic limb buds before they develop pectoral ones. We studied the expression of Pitx1 in X. laevis and E. coqui to determine if this paired-like homeodomain transcription factor directs differentiation specifically of the hindlimb, or if it directs the second pair of limbs to form, namely the forelimbs. We also undertook to determine if embryonic expression patterns were recapitulated during the regeneration of an amputated limb bud. Pitx1 is expressed in hindlimbs in both X. laevis and E. coqui, and expression is similar in both developing and regenerating limb buds. Expression in hindlimbs is restricted to regions of proliferating mesenchyme.Key words: regeneration, Xenopus laevis, limb bud, Pitx1 protein, specification.

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