Ghox 4.7: a chick homeobox gene expressed primarily in limb buds with limb-type differences in expression

Development ◽  
1991 ◽  
Vol 112 (3) ◽  
pp. 791-806 ◽  
Author(s):  
S. Mackem ◽  
K.A. Mahon
Keyword(s):  
Expression Patterns ◽  
Homeobox Genes ◽  
Homeobox Gene ◽  
Limb Bud ◽  
Limb Buds ◽  
Limb Morphogenesis ◽  
Degenerate Oligonucleotide ◽  
Polymerase Chain ◽  
Anterior Posterior

Homeobox genes play a key role in specifying the segmented body plan of Drosophila, and recent work suggests that at least several homeobox genes may play a regulatory role during vertebrate limb morphogenesis. We have used degenerate oligonucleotide primers from highly conserved domains in the homeobox motif to amplify homeobox gene segments from chick embryo limb bud cDNAs using the polymerase chain reaction. Expression of a large number of homeobox genes (at least 17) is detected using this approach. One of these genes contains a novel homeobox loosely related to the Drosophila Abdominal B class, and was further analyzed by determining its complete coding sequence and evaluating its expression during embryogenesis by in situ hybridization. Based on sequence and expression patterns, we have designated this gene as Ghox 4.7 and believe that it is the chick homologue of the murine Hox 4.7 gene (formerly Hox 5.6). Ghox 4.7 is expressed primarily in limb buds during development and shows a striking spatial restriction to the posterior zone of the limb bud, suggesting a role in specifying anterior-posterior pattern formation. In chick, this gene also displays differences in expression between wing and leg buds, raising the possibility that it may participate in specifying limb-type identity.

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.

Why we have (only) five fingers per hand: hox genes and the evolution of paired limbs

Development ◽  
1992 ◽  
Vol 116 (2) ◽  
pp. 289-296 ◽  
Author(s):  
C.J. Tabin
Keyword(s):  
Limb Development ◽  
Hox Genes ◽  
Expression Patterns ◽  
Limb Bud ◽  
Developmental Constraint ◽  
Limb Morphogenesis ◽  
Different Types ◽  
Embryonic Limb ◽  
Limb Pattern ◽  
Anterior Posterior

Limb development has long been a model system for studying vertebrate pattern formation. The advent of molecular biology has allowed the identification of some of the key genes that regulate limb morphogenesis. One important class of such genes are the homeobox-containing, or Hox genes. Understanding of the roles these genes play in development additionally provides insights into the evolution of limb pattern. Hox gene expression patterns divide the embryonic limb bud into five sectors along the anterior/posterior axis. The expression of specific Hox genes in each domain specifies the developmental fate of that region. Because there are only five distinct Hox-encoded domains across the limb bud there is a developmental constraint prohibiting the evolution of more than five different types of digits. The expression patterns of Hox genes in modern embryonic limb buds also gives clues to the shape of the ancestral fin field from which the limb evolved, hence elucidating the evolution of the tetrapod limb.

scholarly journals Extended expression of MaKN1 contributes to the leaf morphology in aquatic forms of Myriophyllum aquaticum

Botany ◽  
2015 ◽  
Vol 93 (9) ◽  
pp. 611-621
Author(s):  
M.D. Shafiullah ◽  
Christian R. Lacroix
Keyword(s):  
Apical Meristem ◽  
Leaf Morphology ◽  
Expression Patterns ◽  
Homeobox Gene ◽  
Leaf Primordia ◽  
Leaf Primordium ◽  
Myriophyllum Aquaticum ◽  
Knox Gene ◽  
Leaf Morphogenesis

Myriophyllum aquaticum (Vell.) Verdc. is heterophyllous in nature with highly dissected simple leaves consisting of several lobes. KNOX (KNOTTED1-LIKE HOMEOBOX) genes are believed to have played an important role in the evolution of leaf diversity. Up-regulation of KNOX during leaf primordium initiation can lead to leaf dissection in plants with simple leaves and, if overexpressed, can produce ectopic meristems on leaves. A previous study on KNOX gene expression in the aerial form of this species showed that this gene is expressed in the shoot apical meristem (SAM), as well as in leaf primordia P0 to P8. Based on these results, it was hypothesized that the prolonged expression of the MaKN1 (Myriophyllum aquaticum Knotted1-like homeobox) gene beyond P8, might play an important role in the generation of more lobes, longer lobes, and hydathode formation in the aquatic leaves of M. aquaticum. The technique of in situ hybridization was carried out using a previously sequenced 300 bp fragment of MaKN1 to determine the expression patterns of this gene in the shoot of aquatic forms of the plant. Expression patterns of MaKN1 revealed that the SAM and leaf primordia of aquatic forms of M. aquaticum at levels P0 (youngest) to P4 were distributed throughout these structures. The level of expression of this MaKN1 gene progressively became more localized to lobes in older leaf primordia (levels P5 to P12). Previous studies of aerial forms of this plant showed MaKN1 expression until P8. Our results with aquatic forms show that the highly dissected leaf morphology in aquatic forms was the result of the prolonged expression of MaKN1 beyond P8. This resulted in the formation of elongated and slightly more numerous lobes, and hydathodes in aquatic forms. These findings support the view that KNOX genes are important developmental regulators of leaf morphogenesis and have played an important role in the evolution of leaf forms in the plant kingdom.

Mouse Wnt genes exhibit discrete domains of expression in the early embryonic CNS and limb buds

Development ◽  
1993 ◽  
Vol 119 (1) ◽  
pp. 247-261 ◽  
Author(s):  
B.A. Parr ◽  
M.J. Shea ◽  
G. Vassileva ◽  
A.P. McMahon
Keyword(s):  
Limb Development ◽  
Expression Patterns ◽  
Limb Buds ◽  
Expression Studies ◽  
The Family ◽  
The Central Nervous System ◽  
Discrete Domains ◽  
Early Developmental ◽  
The Brain

Mutation and expression studies have implicated the Wnt gene family in early developmental decision making in vertebrates and flies. In a detailed comparative analysis, we have used in situ hybridization of 8.0- to 9.5-day mouse embryos to characterize expression of all ten published Wnt genes in the central nervous system (CNS) and limb buds. Seven of the family members show restricted expression patterns in the brain. At least three genes (Wnt-3, Wnt-3a, and Wnt-7b) exhibit sharp boundaries of expression in the forebrain that may predict subdivisions of the region later in development. In the spinal cord, Wnt-1, Wnt-3, and Wnt-3a are expressed dorsally, Wnt-5a, Wnt-7a, and Wnt-7b more ventrally, and Wnt-4 both dorsally and in the floor plate. In the forelimb primordia, Wnt-3, Wnt-4, Wnt-6 and Wnt-7b are expressed fairly uniformly throughout the limb ectoderm. Wnt-5a RNA is distributed in a proximal to distal gradient through the limb mesenchyme and ectoderm. Along the limb's dorsal-ventral axis, Wnt-5a is expressed in the ventral ectoderm and Wnt-7a in the dorsal ectoderm. We discuss the significance of these patterns of restricted and partially overlapping domains of expression with respect to the putative function of Wnt signalling in early CNS and limb development.

Mouse Hox-3.4: homeobox sequence and embryonic expression patterns compared with other members of the Hox gene network

Development ◽  
1990 ◽  
Vol 109 (2) ◽  
pp. 329-339 ◽  
Author(s):  
S.J. Gaunt ◽  
P.L. Coletta ◽  
D. Pravtcheva ◽  
P.T. Sharpe
Keyword(s):  
Gene Network ◽  
Common Ancestor ◽  
Expression Patterns ◽  
Homeobox Gene ◽  
Predicted Amino Acid Sequence ◽  
Chromosome 15 ◽  
Hox Gene ◽  
The Central Nervous System ◽  
Genomic Organisation

A putative mouse homeobox gene (Hox-3.4) was previously identified 4kb downstream of the Hox-3.3 (Hox-6.1)* gene (Sharpe et al. 1988). We have now sequenced the Hox-3.4 homeobox region. The predicted amino acid sequence shows highest degree of homology in the mouse with Hox-1.3 and -2.1. This, together with similarities in the genomic organisation around these three genes, suggests that they are comembers of a subfamily, derived from a common ancestor. Hox-3.4 appears to be a homologue of the Xenopus Xlhbox5 and human cp11 genes (Fritz and De Robertis, 1988; Simeone et al. 1988). Using a panel of mouse-hamster somatic cell hybrids we have mapped the Hox-3.4 gene to chromosome 15. From the results of in situ hybridization experiments, we describe the distribution of Hox-3.4 transcripts within the 12 1/2 day mouse embryo, and we compare this with the distributions of transcripts shown by seven other members of the Hox gene network. We note three consistencies that underlie the patterns of expression shown by Hox-3.4. First, the anterior limits of Hox-3.4 transcripts in the embryo are related to the position of the Hox-3.4 gene within the Hox-3 locus. Second, the anterior limits of Hox-3.4 expression within the central nervous system are similar to those shown by subfamily homologues Hox-2.1 and Hox-1.3, although the tissue-specific patterns of expression for these three genes show many differences. Third, the patterns of Hox-3.4 expression within the spinal cord and the testis are very similar to those shown by a neighbouring Hox-3 gene (Hox-3.3), but they are quite different from those shown by Hox-1 genes (Hox-1.2, -1.3 and -1.4).

scholarly journals Developmental Patterning and Neurogenetic Gradients of Nurr1 Positive Neurons in the Rat Claustrum and Lateral Cortex

2021 ◽  
Vol 15 ◽  
Author(s):  
Chao Fang ◽  
Hong Wang ◽  
Robert Konrad Naumann
Keyword(s):  
Expression Patterns ◽  
Prenatal Development ◽  
Superficial Layer ◽  
Lateral Cortex ◽  
Developmental Progression ◽  
Previous Birth ◽  
Developmental Patterning ◽  
And Function ◽  
Anterior Posterior

The claustrum is an enigmatic brain structure thought to be important for conscious sensations. Recent studies have focused on gene expression patterns, connectivity, and function of the claustrum, but relatively little is known about its development. Interestingly, claustrum-enriched genes, including the previously identified marker Nurr1, are not only expressed in the classical claustrum complex, but also embedded within lateral neocortical regions in rodents. Recent studies suggest that Nurr1 positive neurons in the lateral cortex share a highly conserved genetic expression pattern with claustrum neurons. Thus, we focus on the developmental progression and birth dating pattern of the claustrum and Nurr1 positive neurons in the lateral cortex. We comprehensively investigate the expression of Nurr1 at various stages of development in the rat and find that Nurr1 expression first appears as an elongated line along the anterior-posterior axis on embryonic day 13.5 (E13.5) and then gradually differentiates into multiple sub-regions during prenatal development. Previous birth dating studies of the claustrum have led to conflicting results, therefore, we combine 5-ethynyl-2′-deoxyuridine (EdU) labeling with in situ hybridization for Nurr1 to study birth dating patterns. We find that most dorsal endopiriform (DEn) neurons are born on E13.5 to E14.5. Ventral claustrum (vCL) and dorsal claustrum (dCL) are mainly born on E14.5 to E15.5. Nurr1 positive cortical deep layer neurons (dLn) and superficial layer neurons (sLn) are mainly born on E14.5 to E15.5 and E15.5 to E17.5, respectively. Finally, we identify ventral to dorsal and posterior to anterior neurogenetic gradients within vCL and DEn. Thus, our findings suggest that claustrum and Nurr1 positive neurons in the lateral cortex are born sequentially over several days of embryonic development and contribute toward charting the complex developmental pattern of the claustrum in rodents.

Sonic hedgehog is not required for polarising activity in the Doublefoot mutant mouse limb bud

Development ◽  
1998 ◽  
Vol 125 (3) ◽  
pp. 351-357 ◽  
Author(s):  
C. Hayes ◽  
J.M. Brown ◽  
M.F. Lyon ◽  
G.M. Morriss-Kay
Keyword(s):  
Gene Expression ◽  
Limb Development ◽  
Target Genes ◽  
Anterior Part ◽  
Expression Patterns ◽  
Ectopic Expression ◽  
Mutant Gene ◽  
Limb Bud ◽  
Active Constituent ◽  
Limb Buds

The mouse mutant Doublefoot (Dbf) shows preaxial polydactyly of all four limbs. We have analysed limb development in this mutant with respect to morphogenesis, gene expression patterns and ectopic polarising activity. The results reveal a gain-of-function mutation at a locus that mediates pattern formation in the developing limb. Shh expression is identical with that of wild-type embryos, i.e. there is no ectopic expression. However, mesenchyme from the anterior aspects of Dbf/+ mutant limb buds, when transplanted to the anterior side of chick wing buds, induces duplication of the distal skeletal elements. Mid-distal mesenchymal transplants from early, but not later, Dbf/+ limb buds are also able to induce duplication. This demonstration of polarising activity in the absence of Shh expression identifies the gene at the Dbf locus as a new genetic component of the Shh signalling pathway, which (at least in its mutated form) is able to activate signal transduction independently of Shh. The mutant gene product is sufficient to fulfil the signalling properties of Shh including upregulation of the direct Shh target genes Ptc and Gli, and induction of the downstream target genes Bmp2, Fgf4 and Hoxd13. The expression domains of all these genes extend from their normal posterior domains into the anterior part of the limb bud without being focused on a discrete ectopic site. These observations dissociate polarising activity from Shh gene expression in the Dbf/+ limb bud. We suggest that the product of the normal Dbf gene is a key active constituent of the polarising region, possibly acting in the extracellular compartment.

Correlation of wing-leg identity in ectopic FGF-induced chimeric limbs with the differential expression of chick Tbx5 and Tbx4

Development ◽  
1998 ◽  
Vol 125 (1) ◽  
pp. 51-60 ◽  
Author(s):  
H. Ohuchi ◽  
J. Takeuchi ◽  
H. Yoshioka ◽  
Y. Ishimaru ◽  
K. Ogura ◽  
...  
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Expression Patterns ◽  
Ectopic Expression ◽  
Limb Bud ◽  
Chick Embryos ◽  
Fibroblast Growth ◽  
Limb Buds ◽  
Specific Position

It has been reported that members of the fibroblast growth factor (FGF) family can induce additional limb formation in the flank of chick embryos. The phenotype of the ectopic limb depends on the somite level at which it forms: limbs in the anterior flank resemble wings, whereas those in the posterior flank resemble legs. Ectopic limbs located in the mid-flank appear chimeric, possessing characteristics of both wings and legs; feather buds are present in the anterior halves with scales and claws in the posterior halves. To study the mechanisms underlying the chimerism of these additional limbs, we cloned chick Tbx5 and Tbx4 to use as forelimb and hindlimb markers and examined their expression patterns in FGF-induced limb buds. We found that Tbx5 and Tbx4 were differentially expressed in the anterior and posterior halves of additional limb buds in the mid-flank, respectively, consistent with the chimeric patterns of the integument. A boundary of Tbx5/Tbx4 exists in all ectopic limbs, indicating that the additional limbs are essentially chimeric, although the degree of chimerism is dependent on the position. The boundary of Tbx5/Tbx4 expression is not fixed at a specific position within the interlimb region, but dependent upon where FGF was applied. Since the ectopic expression patterns of Tbx5/Tbx4 in the additional limbs are closely correlated with the patterns of their chimeric phenotypes, it is likely that Tbx5 and Tbx4 expression in the limb bud is involved in determination of the forelimb and hindlimb identities, respectively, in vertebrates.

mRNA expression patterns of the IGF system during mouse limb bud development, determined by whole mount in situ hybridization

1998 ◽  
Vol 138 (1-2) ◽  
pp. 151-161 ◽  
Author(s):  
Marjolein van Kleffens ◽  
Cora Groffen ◽  
Roberto R. Rosato ◽  
Stefan M. van den Eijnde ◽  
Johan W. van Neck ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Mrna Expression ◽  
Expression Patterns ◽  
Limb Bud ◽  
Bud Development ◽  
Igf System ◽  
Whole Mount ◽  
Mouse Limb
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