@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.
}
}
Matrix 16952 of 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).
Matrices
Title: Rigon et al 2013 matrix
Description: Detailed structural data of secondary sensory cells in Tunicata and chordate outgroups. MacClade 4.08.
Rows
|
Taxon Label |
Row Segments |
Characters 1?–30 |
| Botryllus schlosseri |
(none)
|
0100-1101--01001101 |
| Botrylloides leachi |
(none)
|
0100-1101--01001101 |
| Styela plicata |
(none)
|
011001100--01101101 |
| Polyandrocarpa zorritensis |
(none)
|
011001100--01101101 |
| Molgula manhattensis |
(none)
|
011001100--01111111 |
| Pyura stolonifera |
(none)
|
011001100--01111111 |
| Clavelina lepadiformis |
(none)
|
100101---1001000101 |
| Diplosoma listerianum |
(none)
|
100101---0001000101 |
| Ciona intestinalis |
(none)
|
100101---1000001101 |
| Ascidiella aspersa |
(none)
|
100101---1010000101 |
| Phallusia mammillata |
(none)
|
100100----000100101 |
| Chelyosoma productum |
(none)
|
100101---1010000101 |
| Corella inflata |
(none)
|
100100----010000101 |
| Oikopleura dioica |
(none)
|
100111---11010000-1 |
| Pyrosoma atlanticum |
(none)
|
1100-1100--000?0101 |
| Doliolum nationalis |
(none)
|
1100-1100--00000101 |
| Branchiostoma floridae |
(none)
|
1100-1100--000-1100 |
| Lampetra fluviatilis |
(none)
|
1100-101---000-00-0 |
| Eptatretus stouti |
(none)
|
1100-100---000-?0-0 |
| Brachydanio rerio |
(none)
|
1100-101---000-?0-0 |
Columns
| Column |
Character Description |
|
1
|
Single type of secondary sensory cells
|
|
2
|
Secondary sensory cells with a single cilium (monociliary)
|
|
3
|
Secondary sensory cells with two cilia (biciliary)
|
|
4
|
Secondary sensory cells with more than two cilia (pluriciliary)
|
|
5
|
Cilia in pluriciliary sensory cells of same length (0) / different lengths (1)
|
|
6
|
Microvilli or stereovilli on sensory cells
|
|
7
|
Microvilli on monociliary sensory cells
|
|
8
|
Stereovilli on monociliary sensory cells
|
|
9
|
Cilium of monociliary sensory cell surrounded by a ring of microvilli (0) or cilium eccentric to microvilli (1)
|
|
10
|
Microvilli on pluriciliary sensory cells
|
|
11
|
Cilia in pluriciliary sensory cells in a single line (0) or in multiple lines (1)
|
|
12
|
Accessory secretory cells in coronal organ
|
|
13
|
Supporting cells form a wall or crest alongside the coronal organ
|
|
14
|
Electron dense granules in sensory cells
|
|
15
|
Width of coronal organ uniform along oral rim (0) or wider at certain areas (1)
|
|
16
|
Accessory centriole in sensory cells
|
|
17
|
Tentacles or flaps
|
|
18
|
Tentacles simple (0) / braqnched (1)
|
|
19
|
Secondary sensory cells (hair cells) in continuous row: absent (0) / present (1)
|
Go to search
Citation
Taxa
Matrices
Trees
Analyses
