TY - JOUR
T1 - Evolution of flatworm central nervous systems
T2 - Insights from polyclads
AU - Quiroga, Sigmer Y.
AU - Carolina Bonilla, E.
AU - Marcela Bolaños, D.
AU - Carbayo, Fernando
AU - Litvaitis, Marian K.
AU - Brown, Federico D.
N1 - Publisher Copyright:
© 2015, Sociedade Brasileira de Genética.
Copyright:
Copyright 2015 Elsevier B.V., All rights reserved.
PY - 2015/7/1
Y1 - 2015/7/1
N2 - The nervous systems of flatworms have diversified extensively as a consequence of the broad range of adaptations in the group. Here we examined the central nervous system (CNS) of 12 species of polyclad flatworms belonging to 11 different families by morphological and histological studies. These comparisons revealed that the overall organization and architecture of polyclad central nervous systems can be classified into three categories (I, II, and III) based on the presence of globuli cell masses -ganglion cells of granular appearance-, the cross-sectional shape of the main nerve cords, and the tissue type surrounding the nerve cords. In addition, four different cell types were identified in polyclad brains based on location and size. We also characterize the serotonergic and FMRFamidergic nervous systems in the cotylean Boninia divae by immunocytochemistry. Although both neurotransmitters were broadly expressed, expression of serotonin was particularly strong in the sucker, whereas FMRFamide was particularly strong in the pharynx. Finally, we test some of the major hypothesized trends during the evolution of the CNS in the phylum by a character state reconstruction based on current understanding of the nervous system across different species of Platyhelminthes and on up-to-date molecular phylogenies.
AB - The nervous systems of flatworms have diversified extensively as a consequence of the broad range of adaptations in the group. Here we examined the central nervous system (CNS) of 12 species of polyclad flatworms belonging to 11 different families by morphological and histological studies. These comparisons revealed that the overall organization and architecture of polyclad central nervous systems can be classified into three categories (I, II, and III) based on the presence of globuli cell masses -ganglion cells of granular appearance-, the cross-sectional shape of the main nerve cords, and the tissue type surrounding the nerve cords. In addition, four different cell types were identified in polyclad brains based on location and size. We also characterize the serotonergic and FMRFamidergic nervous systems in the cotylean Boninia divae by immunocytochemistry. Although both neurotransmitters were broadly expressed, expression of serotonin was particularly strong in the sucker, whereas FMRFamide was particularly strong in the pharynx. Finally, we test some of the major hypothesized trends during the evolution of the CNS in the phylum by a character state reconstruction based on current understanding of the nervous system across different species of Platyhelminthes and on up-to-date molecular phylogenies.
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U2 - 10.1590/S1415-475738320150013
DO - 10.1590/S1415-475738320150013
M3 - Research Article
AN - SCOPUS:84941639815
SN - 1415-4757
VL - 38
SP - 233
EP - 248
JO - Genetics and Molecular Biology
JF - Genetics and Molecular Biology
IS - 3
ER -