Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Loss of fish actinotrichia proteins and the fin-to-limb transition

Abstract

The early development of teleost paired fins is strikingly similar to that of tetrapod limb buds and is controlled by similar mechanisms1,2. One early morphological divergence between pectoral fins and limbs is in the fate of the apical ectodermal ridge (AER), the distal epidermis that rims the bud. Whereas the AER of tetrapods regresses after specification of the skeletal progenitors3, the AER of teleost fishes forms a fold that elongates4,5. Formation of the fin fold is accompanied by the synthesis of two rows of rigid, unmineralized fibrils called actinotrichia, which keep the fold straight6,7 and guide the migration of mesenchymal cells within the fold5,8. The actinotrichia are made of elastoidin, the components of which, apart from collagen, are unknown. Here we show that two zebrafish proteins, which we name actinodin 1 and 2 (And1 and And2), are essential structural components of elastoidin. The presence of actinodin sequences in several teleost fishes and in the elephant shark (Callorhinchus milii, which occupies a basal phylogenetic position), but not in tetrapods, suggests that these genes have been lost during tetrapod species evolution. Double gene knockdown of and1 and and2 in zebrafish embryos results in the absence of actinotrichia and impaired fin folds. Gene expression profiles in embryos lacking and1 and and2 function are consistent with pectoral fin truncation and may offer a potential explanation for the polydactyly observed in early tetrapod fossils. We propose that the loss of both actinodins and actinotrichia during evolution may have led to the loss of lepidotrichia and may have contributed to the fin-to-limb transition.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Figure 1: Schematic representations of the zebrafish and elephant shark actinodin proteins.
Figure 2: Expression of and1 correlates with the growth of actinotrichia.
Figure 3: Double gene knockdown of and1 and and2 leads to an absence of actinotrichia and reduced or absent fin folds.
Figure 4: Gene expression analysis in pectoral fin buds of double and morphants.

References

  1. 1

    Grandel, H. & Schulte-Merker, S. The development of the paired fins in the zebrafish (Danio rerio). Mech. Dev. 79, 99–120 (1998)

    CAS  Article  Google Scholar 

  2. 2

    Mercader, N. Early steps of paired fin development in zebrafish compared with tetrapod limb development. Dev. Growth Differ. 49, 421–437 (2007)

    CAS  Article  Google Scholar 

  3. 3

    Pizette, S. & Niswander, L. BMPs negatively regulate structure and function of the limb apical ectodermal ridge. Development 126, 883–894 (1999)

    CAS  PubMed  Google Scholar 

  4. 4

    Dane, P. J. & Tucker, J. B. Modulation of epidermal cell shaping and extracellular matrix during caudal fin morphogenesis in the zebrafish Brachydanio rerio. J. Embryol. Exp. Morphol. 87, 145–161 (1985)

    CAS  PubMed  Google Scholar 

  5. 5

    Wood, A. Early pectoral fin development and morphogenesis of the apical ectodermal ridge in the killifish, Aphysosemion scheeli. Anat. Rec. 204, 349–356 (1982)

    CAS  Article  Google Scholar 

  6. 6

    Bouvet, J. Différenciation et ultrastructure du squelette distal de la nageoire pectorale chez la truite indigène (Salmo Trutta Fario L.). I. Différenciation et ultrastructure des actinotriches. Arch. Anat. Microsc. Morphol. Exp. 63, 79–96 (1974)

    CAS  PubMed  Google Scholar 

  7. 7

    Géraudie, J. Initiation of the actinotrichial development in the early fin bud of the fish, Salmo. J. Morphol. 151, 353–361 (1977)

    Article  Google Scholar 

  8. 8

    Wood, A. & Thorogood, P. An analysis of in vitro cell migration during teleost fin morphogenesis. J. Cell Sci. 66, 205–222 (1984)

    CAS  PubMed  Google Scholar 

  9. 9

    Garrault, H. Développement des fibres d’élastoidine (actinotrichia) chez les salmonides. Arch. Anat. Microsc. 130, 105–137 (1936)

    Google Scholar 

  10. 10

    Krukenberg, C. F. Ueber die chemische Beschaffenheit der sog. Hornfäden von Mustelus und über die Zusammensetzung der keratinösen Hüllen um den Eiern von Scyllium stellate. Mitt. Zool. Stat. Neapel 6, 286–296 (1885)

    Google Scholar 

  11. 11

    Damodaran, M., Sivaraman, C. & Dhavalikar, R. S. Amino acid composition of elastoidin. Biochem. J. 62, 621–625 (1956)

    CAS  Article  Google Scholar 

  12. 12

    Kimura, S. & Kubota, M. Studies on elastoidin I. Some chemical and physical properties of elastoidin and its components. J. Biochem. 60, 615–621 (1966)

    CAS  Article  Google Scholar 

  13. 13

    Kimura, S., Uematsu, Y. & Miyauchi, Y. Shark (Prionace glauca) elastoidin: characterization of its collagen as [alpha 1(E)]3 homotrimers. Comp. Biochem. Physiol. B 84, 305–308 (1986)

    CAS  Article  Google Scholar 

  14. 14

    Padhi, B. K. et al. Screen for genes differentially expressed during regeneration of the zebrafish caudal fin. Dev. Dyn. 231, 527–541 (2004)

    CAS  Article  Google Scholar 

  15. 15

    Seidah, N. G. & Chretien, M. Proprotein and prohormone convertases: a family of subtilases generating diverse bioactive polypeptides. Brain Res. 848, 45–62 (1999)

    CAS  Article  Google Scholar 

  16. 16

    Andrade, M. A., Perez-Iratxeta, C. & Ponting, C. P. Protein repeats: structures, functions, and evolution. J. Struct. Biol. 134, 117–131 (2001)

    CAS  Article  Google Scholar 

  17. 17

    Géraudie, J. in Biology of Invertebrate and Lower Vertebrate Collagens (eds Bairati, A. & Garrone, R.) 451–455 (Plenum, 1985)

    Book  Google Scholar 

  18. 18

    Nishidate, M., Nakatani, Y., Kudo, A. & Kawakami, A. Identification of novel markers expressed during fin regeneration by microarray analysis in medaka fish. Dev. Dynamics 236, 2685–2693 (2007)

    CAS  Article  Google Scholar 

  19. 19

    Venkatesh, B. et al. Survey sequencing and comparative analysis of the elephant shark (Callorhinchus milii). PLoS Biol. 5, e101 (2007)

    Article  Google Scholar 

  20. 20

    Martin, G. R. The roles of FGFs in the early development of vertebrate limbs. Genes Dev. 12, 1571–1586 (1998)

    CAS  Article  Google Scholar 

  21. 21

    Ahn, D. & Ho, R. K. Tri-phasic expression of posterior Hox genes during development of pectoral fins in zebrafish: implications for the evolution of vertebrate paired appendages. Dev. Biol. 322, 220–233 (2008)

    CAS  Article  Google Scholar 

  22. 22

    Sordino, P., van der Hoeven, F. & Duboule, D. Hox gene expression in teleost fins and the origin of vertebrate digits. Nature 375, 678–681 (1995)

    ADS  CAS  Article  Google Scholar 

  23. 23

    Mao, J., McGlinn, E., Huang, P., Tabin, C. J. & McMahon, A. P. Fgf-dependent Etv4/5 activity is required for posterior restriction of Sonic hedgehog and promoting outgrowth of the vertebrate limb. Dev. Cell 16, 600–606 (2009)

    CAS  Article  Google Scholar 

  24. 24

    Zhang, Z., Verheyden, J. M., Hassel, J. A. & Sun, X. FGF-regulated Etv genes are essential for repressing Shh expression in mouse limb buds. Dev. Cell 16, 607–613 (2009)

    CAS  Article  Google Scholar 

  25. 25

    Büscher, D., Bosse, B., Heymer, J. & Ruther, U. Evidence for genetic control of Sonic hedgehog by Gli3 in mouse limb development. Mech. Dev. 62, 175–182 (1997)

    Article  Google Scholar 

  26. 26

    Zakany, J., Zacchetti, G. & Duboule, D. Interactions between HOXD and Gli3 genes control the limb apical ectodermal ridge via Fgf10. Dev. Biol. 306, 883–893 (2007)

    CAS  Article  Google Scholar 

  27. 27

    Long, J. A. & Gordon, M. S. The greatest step in vertebrate history: a paleobiological review of the fish-tetrapod transition. Physiol. Biochem. Zool. 77, 700–719 (2004)

    Article  Google Scholar 

  28. 28

    Hui, C. C. & Joyner, A. L. A mouse model of Greig cephalopolysyndactyly syndrome: the extra-toesJ mutation contains an intragenic deletion of the Gli3 gene. Nature Genet. 3, 241–246 (1993)

    CAS  Article  Google Scholar 

  29. 29

    Smith, A. et al. Gene expression analysis on sections of zebrafish regenerating fins reveals limitations in the whole-mount in situ hybridization method. Dev. Dyn. 237, 417–425 (2008)

    CAS  Article  Google Scholar 

  30. 30

    Choo, B. G. et al. Zebrafish transgenic enhancer TRAP line database (ZETRAP). BMC Dev. Biol. 6, 5 (2006)

    Article  Google Scholar 

  31. 31

    Thisse, C. & Thisse, B. High-resolution in situ hybridization to whole-mount zebrafish embryos. Nature Protocols 3, 59–69 (2008)

    CAS  Article  Google Scholar 

  32. 32

    Tyurina, O. V. et al. Zebrafish Gli3 functions as both an activator and a repressor in Hedgehog signaling. Dev. Biol. 277, 537–556 (2005)

    CAS  Article  Google Scholar 

  33. 33

    Lang, C. et al. Molecular characterization and developmentally regulated expression of Xenopus lamina-associated polypeptide 2 (XLAP2). J. Cell Sci. 112, 749–759 (1999)

    CAS  PubMed  Google Scholar 

  34. 34

    Thummel, R. et al. Inhibition of zebrafish fin regeneration using in vivo electroporation of morpholinos against fgfr1 and msxb. Dev. Dyn. 235, 336–346 (2006)

    CAS  Article  Google Scholar 

  35. 35

    Avaron, F., Hoffman, L., Guay, D. & Akimenko, M. A. Characterization of two new zebrafish members of the hedgehog family: atypical expression of a zebrafish indian hedgehog gene in skeletal elements of both endochondral and dermal origins. Dev. Dyn. 235, 478–489 (2006)

    CAS  Article  Google Scholar 

Download references

Acknowledgements

The authors would like to thank I. Duran for technical advice, A. Maurya for assistance in the early stages of this work and M. Ekker, F. Avaron and M. Debiais for discussions and critical reading of the manuscript. L.S.-P. is supported by a European Modular Biology Organization Long-Term Fellowship (ALT 325-2008). This work was supported by grants to M.-A.A. from the Natural Science Engineering and Research Council of Canada and the Canadian Institutes of Health Research. M.A.A.-N. received funding from the Canada Research Chairs programme and from the Helmholtz Alliance on Systems Biology. V.K. received funding from the Agency for Science, Technology and Research of Singapore.

Author information

Affiliations

Authors

Contributions

J.Z., P.W., D.G. and B.K.P. performed the experiments; J.Z. collected and analysed the data; V.K. produced and provided the enhancer-trap transgenic line; M.A.A.-N. and L.S.-P. performed the analysis of the actinodin sequences; and M.-A.A. designed experiments, analysed data and wrote the manuscript.

Corresponding author

Correspondence to Marie-Andrée Akimenko.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

This file contains Supplementary Figures 1-11 with legends and References. (PDF 11241 kb)

PowerPoint slides

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Zhang, J., Wagh, P., Guay, D. et al. Loss of fish actinotrichia proteins and the fin-to-limb transition. Nature 466, 234–237 (2010). https://doi.org/10.1038/nature09137

Download citation

Further reading

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing