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Citation for Study 14197

Citation title: "Evolutionary diversification of secondary mechanoreceptor cells in Tunicata".

Study name: "Evolutionary diversification of secondary mechanoreceptor cells in Tunicata".

This study is part of submission 14197 (Status: Published).

Citation

Rigon F., Stach T., Federico C., Gasparini F., Burighel P., & Manni L. 2013. Evolutionary diversification of secondary mechanoreceptor cells in Tunicata. BMC Evolutionary Biology, .

Authors

• Rigon F.
• Stach T. (submitter) 00493020936200
• Federico C.
• Gasparini F.
• Burighel P.
• Manni L.

Abstract

Background. Hair cells are vertebrate secondary sensory cells located in the ear and in the lateral line organ. Until recently, these cells were considered to be mechanoreceptors exclusively found in vertebrates that evolved within this group. Evidence of secondary mechanoreceptors in some tunicates, the proposed sister group of vertebrates, has recently led to the hypothesis that vertebrate and tunicate secondary sensory cells share a common origin. Secondary sensory cells were described in detail in two tunicate groups, ascidians and thaliaceans, in which they constitute an oral sensory structure called the coronal organ. Among thaliaceans, the organ is absent in salps and it has been hypothesised that this condition is due to a different feeding system adopted by this group of animals. No information is available as to whether a comparable structure exists in the third group of tunicates, the appendicularians, although different sensory structures are known to be present in these animals. Results. We studied the detailed morphology of appendicularian oral mechanoreceptors. Using light and electron microscopy we could demonstrate that the mechanosensory organ called the circumoral ring is composed of secondary sensory cells. We described the ultrastructure of the circumoral organ in two appendicularian species, Oikopleura dioica and Oikopleura albicans, and thus taxonomically completed the data collection of tunicate secondary sensory cells. To understand the evolution of secondary sensory cells in tunicates, we performed a cladistic analysis using morphological data. We constructed a matrix consisting of 19 characters derived from detailed ultrastructural studies in 16 tunicate species and used a cephalochordate and three vertebrate species as outgroups. Conclusions. Our study clearly shows that the circumoral ring is the appendicularian homologue of the coronal organ of other tunicate taxa. The cladistic analysis enabled us to reconstruct the features of the putative ancestral hair cell in tunicates, represented by a simple monociliated cell. This cell successively differentiated into the current variety of oral mechanoreceptors in the various tunicate lineages. Finally, we demonstrated that the inferred evolutionary changes coincide with major transitions in the feeding strategies in each respective lineage.

Keywords

cladistic analysis, Oikopleura albicans, Oikopleura dioica, sensory cells

External links

About this resource

• Canonical resource URI: http://purl.org/phylo/treebase/phylows/study/TB2:S14197
• Other versions: Nexus NeXML
• Show BibTeX reference

  		@ARTICLE{TreeBASE2Ref21970,
  	 author = {Francesca  Rigon and Thomas  Stach and Caicci   federico and Fabio  Gasparini and Paolo  Burighel and Lucia  Manni},
  	 title = {Evolutionary diversification of secondary mechanoreceptor cells in Tunicata},
  	 year = {2013},
  	 keywords = {cladistic analysis, Oikopleura albicans, Oikopleura dioica, sensory cells},
  	 doi = {},
  	 url = {http://},
  	 pmid = {},
  	 journal = {BMC Evolutionary Biology},
  	 volume = {},
  	 number = {},
  	 pages = {},
  	 abstract = {Background. Hair cells are vertebrate secondary sensory cells located in the ear and in the lateral line organ. Until recently, these cells were considered to be mechanoreceptors exclusively found in vertebrates that evolved within this group. Evidence of secondary mechanoreceptors in some tunicates, the proposed sister group of vertebrates, has recently led to the hypothesis that vertebrate and tunicate secondary sensory cells share a common origin. Secondary sensory cells were described in detail in two tunicate groups, ascidians and thaliaceans, in which they constitute an oral sensory structure called the coronal organ. Among thaliaceans, the organ is absent in salps and it has been hypothesised that this condition is due to a different feeding system adopted by this group of animals. No information is available as to whether a comparable structure exists in the third group of tunicates, the appendicularians, although different sensory structures are known to be present in these animals. 
  Results. We studied the detailed morphology of appendicularian oral mechanoreceptors. Using light and electron microscopy we could demonstrate that the mechanosensory organ called the circumoral ring is composed of secondary sensory cells. We described the ultrastructure of the circumoral organ in two appendicularian species, Oikopleura dioica and Oikopleura albicans, and thus taxonomically completed the data collection of tunicate secondary sensory cells. To understand the evolution of secondary sensory cells in tunicates, we performed a cladistic analysis using morphological data. We constructed a matrix consisting of 19 characters derived from detailed ultrastructural studies in 16 tunicate species and used a cephalochordate and three vertebrate species as outgroups.
  Conclusions. Our study clearly shows that the circumoral ring is the appendicularian homologue of the coronal organ of other tunicate taxa. The cladistic analysis enabled us to reconstruct the features of the putative ancestral hair cell in tunicates, represented by a simple monociliated cell. This cell successively differentiated into the current variety of oral mechanoreceptors in the various tunicate lineages. Finally, we demonstrated that the inferred evolutionary changes coincide with major transitions in the feeding strategies in each respective lineage.
  }
  }
  		

• Show RIS reference

  		TY  - JOUR
  ID  - 21970
  AU  - Rigon,Francesca 
  AU  - Stach,Thomas 
  AU  -  federico,Caicci 
  AU  - Gasparini,Fabio 
  AU  - Burighel,Paolo 
  AU  - Manni,Lucia 
  T1  - Evolutionary diversification of secondary mechanoreceptor cells in Tunicata
  PY  - 2013
  KW  - cladistic analysis
  KW  - Oikopleura albicans
  KW  - Oikopleura dioica
  KW  - sensory cells
  UR  - http://dx.doi.org/
  N2  - Background. Hair cells are vertebrate secondary sensory cells located in the ear and in the lateral line organ. Until recently, these cells were considered to be mechanoreceptors exclusively found in vertebrates that evolved within this group. Evidence of secondary mechanoreceptors in some tunicates, the proposed sister group of vertebrates, has recently led to the hypothesis that vertebrate and tunicate secondary sensory cells share a common origin. Secondary sensory cells were described in detail in two tunicate groups, ascidians and thaliaceans, in which they constitute an oral sensory structure called the coronal organ. Among thaliaceans, the organ is absent in salps and it has been hypothesised that this condition is due to a different feeding system adopted by this group of animals. No information is available as to whether a comparable structure exists in the third group of tunicates, the appendicularians, although different sensory structures are known to be present in these animals. 
  Results. We studied the detailed morphology of appendicularian oral mechanoreceptors. Using light and electron microscopy we could demonstrate that the mechanosensory organ called the circumoral ring is composed of secondary sensory cells. We described the ultrastructure of the circumoral organ in two appendicularian species, Oikopleura dioica and Oikopleura albicans, and thus taxonomically completed the data collection of tunicate secondary sensory cells. To understand the evolution of secondary sensory cells in tunicates, we performed a cladistic analysis using morphological data. We constructed a matrix consisting of 19 characters derived from detailed ultrastructural studies in 16 tunicate species and used a cephalochordate and three vertebrate species as outgroups.
  Conclusions. Our study clearly shows that the circumoral ring is the appendicularian homologue of the coronal organ of other tunicate taxa. The cladistic analysis enabled us to reconstruct the features of the putative ancestral hair cell in tunicates, represented by a simple monociliated cell. This cell successively differentiated into the current variety of oral mechanoreceptors in the various tunicate lineages. Finally, we demonstrated that the inferred evolutionary changes coincide with major transitions in the feeding strategies in each respective lineage.
  
  L3  - 
  JF  - BMC Evolutionary Biology
  VL  - 
  IS  - 
  ER  -