Development Genes and Evolution

, Volume 215, Issue 7, pp 358–363 | Cite as

Eggs and embryos in Xenoturbella (phylum uncertain) are not ingested prey

Original Article

Abstract

Xenoturbella is an enigmatic animal that has puzzled science for almost a century. The eggs and embryos found in Xenoturbella have recently been interpreted as ingested prey. However, PCR on individual eggs as well as in situ hybridisation and in situ PCR unambiguously show that they are Xenoturbella’s own. The eggs and embryos are individually enclosed within follicles with the same ultrastructure. The cortical granules in oocytes and eggs from Xenoturbella but not Nucula stained positively with an antiserum against Reissner’s substance. The embryos incorporated 5-bromodeoxyuridine in vivo, i.e. they replicate their genome and are living.

Keywords

Xenoturbella Deuterostome evolution Cytochrome oxidase 

Supplementary material

427_2005_485_ESM_supp.pdf (308 kb)
(308 KB)

References

  1. Bourlat SJ, Nielsen C, Lockyer AE, Littlewood DTJ, Telford MJ (2003) Xenoturbella is a deuterostome that eats molluscs. Nature 424:925–928Google Scholar
  2. Bullock TH (1965) Structure and function in the nervous systems of invertebrates, I–II. Freeman, San FranciscoGoogle Scholar
  3. Franzén Å, Afzelius BA (1987) The ciliated epidermis of Xenoturbella bocki (Platyhelminthes, Xenoturbellida) with some phylogenetic considerations. Zool Scr 16:9–17Google Scholar
  4. Harrison FW (1991–1999) Microscopic anatomy of invertebrates. Wiley-Liss, New YorkGoogle Scholar
  5. Israelsson O (1997) [Xenoturbella’s molluscan relatives ...] and molluscan embryogenesis. Nature 390:32Google Scholar
  6. Israelsson O (1999) New light on the enigmatic Xenoturbella (phylum uncertain): ontogeny and phylogeny. Proc R Soc Lond B Biol Sci 266:835–841Google Scholar
  7. Israelsson O (2000) Xenoturbella. Ph.D. thesis, Stockholm UniversityGoogle Scholar
  8. Lundin K (1998) The epidermal ciliary rootlets of Xenoturbella bocki (Xenoturbellida) revisited: new support for a possible kinship with the Acoelomorpha (Platyhelminthes). Zool Scr 27:263–270Google Scholar
  9. Muruke MHS, Kivaisi AK, Magingo FSS, Danell E (2002) Identification of mushroom mycelia using DNA techniques. Tanzan J Sci 28:115–128Google Scholar
  10. Norén M, Jondelius U (1997) Xenoturbella’s molluscan relatives ... [... and molluscan embryogenesis]. Nature 390:31–32Google Scholar
  11. Nuovo GJ (1998) PCR in situ hybridization. Lippincott-Raven, PhiladelphiaGoogle Scholar
  12. Reisinger E (1960) Was ist Xenoturbella? Z wiss Zool 164:188–198Google Scholar
  13. Westblad E (1949) Xenoturbella bocki n.g., n.sp., a peculiar, primitive turbellarian type. Ark Zool 1:3–29Google Scholar
  14. Viehweg J, Naumann WW, Olsson R (1998) Secretory radial glia in the ectoneural system of the sea star Asterias rubens (Echinodermata). Acta Zool 79:119–131Google Scholar

Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  1. 1.Museum of EvolutionUppsala UniversityUppsalaSweden
  2. 2.Department of Earth Sciences, PaleobiologyUppsala UniversityUppsalaSweden

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