HoxD expression in the fin-fold compartment of basal gnathostomes and implications for paired appendage evolution

• Published in: Scientific reports Vol. 6; no. 1; p. 22720
• Main Authors: Tulenko, Frank J., Augustus, Gaius J., Massey, James L., Sims, Seth E., Mazan, Sylvie, Davis, Marcus C.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 04-03-2016; Nature Publishing Group
• Subjects: 14/63; 38; 38/23; 38/77; 631/136/756; 631/181/2806; Animal Fins - embryology; Animals; Buds; Earth Sciences; Evolution; Fishes - embryology; Gene expression; Gene Expression Profiling; Gene Expression Regulation, Developmental; Genes; Homeobox; Homeodomain Proteins - biosynthesis; Humanities and Social Sciences; Life Sciences; multidisciplinary; Nesting; Oceanography; Science; Science (multidisciplinary); Sciences of the Universe; Sequence Analysis, DNA; Skin; Transcription factors
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep22720

The role of Homeobox transcription factors during fin and limb development have been the focus of recent work investigating the evolutionary origin of limb-specific morphologies. Here we characterize the expression of
HoxD
genes, as well as the cluster-associated genes
Evx2
and
LNP
, in the paddlefish
Polyodon spathula
, a basal ray-finned fish. Our results demonstrate a collinear pattern of nesting in early fin buds that includes
HoxD14
, a gene previously thought to be isolated from global
Hox
regulation. We also show that in both
Polyodon
and the catshark
Scyliorhinus canicula
(a representative chondrichthyan) late phase
HoxD
transcripts are present in cells of the fin-fold and co-localize with
And1
, a component of the dermal skeleton. These new data support an ancestral role for
HoxD
genes in patterning the fin-folds of jawed vertebrates, and fuel new hypotheses about the evolution of cluster regulation and the potential downstream differentiation outcomes of distinct
HoxD
-regulated compartments.