Limb Evolution: Fish fins or tetrapod limbs — a simple twist of fate?

Coates, Michael I.

doi:10.1016/s0960-9822(95)00169-2

Cited by 44 publications

(31 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In this context, important parameters could be determined by the specific times of recruitment of the HoxA and HoxD complexes in distal appendages, followed by gene-specific expression patterns, to build up locally effective Hox protein doses to determine cellular growth rates. The potential successive activation of these two Hox complexes in the course of limb evolution is supported by both developmental and phylogenetic arguments (17,(31)(32)(33). During limb development, distal expression of Hoxa-13 is observed before that of Hoxd-13 and appears to be generated through a different dynamic, which does not necessarily involve the apparent anterior expansion of Hoxd expression domains (32,(34)(35)(36).…”

Section: Discussionmentioning

confidence: 98%

Regulation of number and size of digits by posterior Hox genes: A dose-dependent mechanism with potential evolutionary implications

Zákány

Fromental-Ramain

Warot

et al. 1997

Proc. Natl. Acad. Sci. U.S.A.

209

102

View full text Add to dashboard Cite

The proper development of digits, in tetrapods, requires the activity of several genes of the HoxA and HoxD homeobox gene complexes. By using a variety of lossof-function alleles involving the five Hox genes that have been described to affect digit patterning, we report here that the group 11, 12, and 13 genes control both the size and number of murine digits in a dose-dependent fashion, rather than through a Hox code involving differential qualitative functions. A similar dose-response is observed in the morphogenesis of the penian bone, the baculum, which further suggests that digits and external genitalia share this genetic control mechanism. A progressive reduction in the dose of Hox gene products led first to ectrodactyly, then to olygodactyly and adactyly. Interestingly, this transition between the pentadactyl to the adactyl formula went through a step of polydactyly. We propose that in the distal appendage of polydactylous short-digited ancestral tetrapods, such as Acanthostega, the HoxA complex was predominantly active. Subsequent recruitment of the HoxD complex contributed to both reductions in digit number and increase in digit length. Thus, transition through a polydactylous limb before reaching and stabilizing the pentadactyl pattern may have relied, at least in part, on asynchronous and independent changes in the regulation of HoxA and HoxD gene complexes.Posterior (AbdB-related) Hox genes belonging to both the HoxD and the HoxA complexes are necessary for the proper organization and development of tetrapod digits (for review, see ref.

show abstract

Section: Discussionmentioning

confidence: 98%

Regulation of number and size of digits by posterior Hox genes: A dose-dependent mechanism with potential evolutionary implications

Zákány

Fromental-Ramain

Warot

et al. 1997

Proc. Natl. Acad. Sci. U.S.A.

209

102

View full text Add to dashboard Cite

show abstract

“…5Ј HOXA and HOXD genes are expressed in pectoral and pelvic fins, although these are morphologically dissimilar. 5,12 Hoxc6 is expressed in a wedge-shaped domain at the anterior-proximal region of pectoral limb and fin buds 61 and is involved in tetrapod shoulder girdle formation. However, Hox gene expression domains in zebrafish fin-pairs are abbreviated distally, and appear to be monophasic or biphasic instead of triphasic, as in limb buds.…”

Section: Review Articlesmentioning

confidence: 99%

Fins, limbs, and tails: outgrowths and axial patterning in vertebrate evolution

1998

Self Cite

View full text Add to dashboard Cite

Current phylogenies show that paired fins and limbs are unique to jawed vertebrates and their immediate ancestry. Such fins evolved first as a single pair extending from an anterior location, and later stabilized as two pairs at pectoral and pelvic levels. Fin number, identity, and position are therefore key issues in vertebrate developmental evolution. Localization of the AP levels at which developmental signals initiate outgrowth from the body wall may be determined by Hox gene expression patterns along the lateral plate mesoderm. This regionalization appears to be regulated independently of that in the paraxial mesoderm and axial skeleton. When combined with current hypotheses of Hox gene phylogenetic and functional diversity, these data suggest a new model of fin/limb developmental evolution. This coordinates body wall regions of outgrowth with primitive boundaries established in the gut, as well as the fundamental nonequivalence of pectoral and pelvic structures.

show abstract

“…In effect, the branching and segmentation model specifies an evolutionary developmental constraint: most elements of the limb must arise from elements that have already appeared. These ideas have been very influential: they have been used as an elegant heuristic device for interpreting developmental analyses of zebrafish fins, (3,4) and the relation of primitive tetrapod limb patterns to sarcopterygian fins. (12) They have also contributed to a heated debate over the phylogenetic position of birds.…”

Section: Problems and Paradigmsmentioning

confidence: 99%

“…However, if their definition is extended to characterize axes in fins beyond this clade, (3) then inconsistencies arise. For example, the posterior radial of the pectoral fin in Polypterus (a non-teleost actinopterygian) has been identified as a metapterygium.…”

Section: The Metapterygial Axis In Evolutionmentioning

confidence: 99%

See 1 more Smart Citation

Branching, segmentation and the metapterygial axis: pattern versus process in the vertebrate limb

et al. 2002

View full text Add to dashboard Cite

Explanations of the patterns of vertebrate fin and limb evolution are improving as specific hypotheses based on molecular and developmental data are proposed and tested. Comparative analyses of gene expression patterns and functions in developing limbs, and morphological patterns in embryonic, adult and fossil limbs point to digit specification as a key developmental innovation associated with the origin of tetrapods. Digit development during the fin-to-limb transition involved sustained proximodistal outgrowth and a new phase of Hox gene expression in the distal fin bud. These patterning changes in the distal limb have been explained by the linked concepts of the metapterygial axis and the digital arch. These have been proposed to account for the generation of limb pattern by sequential branching and segmentation of precartilagenous elements along the proximodistal axis of the limb. While these ideas have been very fruitful, they have become increasingly difficult to reconcile with experimental and comparative studies of fin and limb development. Here we argue that limb development does not involve a branching mechanism, and reassess the concept of a metapterygial axis in limb development and evolution.

show abstract

Limb Evolution: Fish fins or tetrapod limbs — a simple twist of fate?

Abstract: Comparisons between Hox gene expression patterns in teleost fins and tetrapod limbs are revealing new insights into the developmental mechanisms underlying the evolutionary transition from fin to limb.

Cited by 44 publications

References 14 publications

Regulation of number and size of digits by posterior Hox genes: A dose-dependent mechanism with potential evolutionary implications

Regulation of number and size of digits by posterior Hox genes: A dose-dependent mechanism with potential evolutionary implications

Fins, limbs, and tails: outgrowths and axial patterning in vertebrate evolution

Branching, segmentation and the metapterygial axis: pattern versus process in the vertebrate limb

Contact Info

Product

Resources

About