uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Ultrastructure and tubulin immunocytochemistry of the copulatory stylet-like structure in Childia species (acoela)
Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolution, Genomics and Systematics, Systematic Zoology.
Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolution, Genomics and Systematics, Systematic Zoology.
Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolution, Genomics and Systematics, Systematic Zoology.
2007 (English)In: Journal of morphology (1931. Print), ISSN 0362-2525, E-ISSN 1097-4687, Vol. 268, no 2, 166-180 p.Article in journal (Refereed) Published
Abstract [en]

One of the main characters used in acoel taxonomy is the male copulatory organ. Despite this, ultrastructural studies of this structure are scarce. We studied the ultrastructure of the copulatory organ in eight species of acoels belonging to the taxon Childia. Members of Childia possess a well-developed conical or cylindrical stylet-like structure composed of needles. Immunogold cytochemistry of tubulin was used to determine the composition of the needles. Stylet-like structures of Childia species at the ultrastructural level are basically similar. Stylet needles show intracellular differentiations. As shown both by ultrastructural and immunocytochemical methods, the stylet needles, in all species studied, are composed of long, parallel microtubules, either tightly packed or polymerized. We report unusual polymerization of microtubules, resulting in formation of a honeycomb-like structure in cross section. Variations of ultrastructure among Childia species include numbers and arrangement of stylet needles, shape of needles, needle compactness, microtubule polymerization, direction of stylet growth, and presence/absence of different types of granules. The stylet-like structures are homologous within Childia, but are likely to prove nonhomologous with the other needle-like structures found in acoel copulatory organs. Stylets in Platyhelminthes are not homologous with stylet-like structures in acoels.

Place, publisher, year, edition, pages
2007. Vol. 268, no 2, 166-180 p.
Keyword [en]
Acoela, Microtubules, Polymerization, Stylet, Stylet needles, Tubulin, Ultrastructure
National Category
Biological Sciences
Identifiers
URN: urn:nbn:se:uu:diva-93958DOI: 10.1002/jmor.10502ISI: 000243916500005PubMedID: 17236190OAI: oai:DiVA.org:uu-93958DiVA: diva2:167621
Available from: 2006-01-26 Created: 2006-01-26 Last updated: 2017-12-14Bibliographically approved
In thesis
1. Phylogeny and Taxonomy of Childia (Acoela): New characters for unraveling acoel phylogenies from molecules, ultrastructure, immunocytochemistry and confocal microscopy
Open this publication in new window or tab >>Phylogeny and Taxonomy of Childia (Acoela): New characters for unraveling acoel phylogenies from molecules, ultrastructure, immunocytochemistry and confocal microscopy
2006 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This thesis presents a comprehensive phylogenetic and taxonomic study of an acoel subgroup, the Childiidae. Members of this taxon are characterized by well-developed male copulatory organs with conical/cylindrical stylets. The phylogenetic analyses, by means of total evidence approach, based on three molecular markers (18S and 28S rRNA genes and Histone H3) and 50 morphological characters reaffirm the non-monophyly of the Childiidae sensu Dörjes, 1968 (Actinoposthiidae and Childia+Paraphanostoma). The total evidence phylogeny strongly support the Childia+Paraphanostoma clade separate from other former members of the Childiidae, which are now placed in Actinoposthiidae. The monophyly of Childia+Paraphanostoma is well corroborated by several morphological characters. A new taxon Childia is defined, in accordance with the PhyloCode, comprising all former Paraphanostoma species and a member of the monotypic genus C. groenlandica. A new diagnosis for the current members of Childia is provided.

Several structures, shown to hold promising phylogenetic signals for unraveling acoel relationships, such as musculature pattern, sperm and male copulatory organs, are investigated, using a combination of traditional and modern techniques (ultrastructure, immunocytochemistry and confocal microscopy), with main focus on Childia and its closest relatives. New characters are described and their phylogenetic significance assessed. Morphological characters relating to body-wall musculature, statocyst muscles, male copulatory organ musculature and ultrastructure, and sperm cytoplasmic granules are shown to carry important phylogenetic signals at lower taxonomic levels, while most of the characters related to sperm ultrastructure are useful at higher taxonomic levels within the Acoela. The data obtained undermine the phylogenetic use of the seminal bursa in Childia. In addition to this, it is shown that most of the classical morphological characters used in acoel taxonomy, obtained using traditional histological methods, may be misleading in identifying monophyletic entities within the Acoela.

The most corroborated synapomorphies, identified in this thesis, are used in determining the taxonomic placement of a new viviparous acoel, Childia vivipara, into the taxon Childia.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2006. 44 p.
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 140
Keyword
Biology, Childiidae, Childia, Paraphanostoma, Acoela, phylogeny, taxonomy, morphology, 18S rRNA, 28S rRNA, Histone H3, ultrastructure, confocal, phalloidin, immunocytochemistry, Biologi
National Category
Biological Sciences
Identifiers
urn:nbn:se:uu:diva-6315 (URN)91-554-6448-3 (ISBN)
Public defence
2006-02-24, Zootissalen, EBC, Villavägen 9, Uppsala, 10:00 (English)
Opponent
Supervisors
Available from: 2006-01-26 Created: 2006-01-26 Last updated: 2013-06-13Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textPubMed
By organisation
Systematic Zoology
In the same journal
Journal of morphology (1931. Print)
Biological Sciences

Search outside of DiVA

GoogleGoogle Scholar

doi
pubmed
urn-nbn

Altmetric score

doi
pubmed
urn-nbn
Total: 544 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf