Zur Feinstruktur der Sinnesorgane von Lineus ruber O.F. M�ller (Nemertini, Heteronemertini)

1971 ◽  
Vol 117 (2) ◽  
pp. 212-225 ◽  
Author(s):  
Volker Storch ◽  
Karen Moritz
Keyword(s):  
Lineus Ruber

Localisation du réflexe lucifuge dans les ganglions cérébroïdes dorsaux de la némerte marine, Lineus ruber (O. F. Müller): étude expérimentale

1992 ◽  
Vol 70 (4) ◽  
pp. 750-752
Author(s):  
G. Vernet
Keyword(s):  
Experimental Study ◽  
Anterior Part ◽  
Etude Expérimentale ◽  
Negative Phototaxis ◽  
Cerebral Ganglia ◽  
Lineus Ruber ◽  
Étude Expérimentale

The anterior part of Lineus ruber contains four successive "segments", an antecerebral segment, a second segment containing the cerebral ganglia, a third segment containing the cerebral organs, and lastly a preoesophageal segment. An experimental study involving microsurgical removal followed or not by grafts of different segments has shown that the negative phototaxis of this marine nemertean has its origins in the dorsal cerebral ganglia, in the photoreceptive structure that we have described.

scholarly journals Embryonic chirality and the evolution of spiralian left–right asymmetries

2016 ◽  
Vol 371 (1710) ◽  
pp. 20150411 ◽  
Author(s):  
José M. Martín-Durán ◽  
Bruno C. Vellutini ◽  
Andreas Hejnol
Keyword(s):  
Early Event ◽  
Animal Group ◽  
Differential Activation ◽  
Membranipora Membranacea ◽  
Axis Specification ◽  
Left Right Asymmetry ◽  
Cytoskeleton Dynamics ◽  
Lineus Ruber ◽  
Asymmetric Expression

The group Spiralia includes species with one of the most significant cases of left–right asymmetries in animals: the coiling of the shell of gastropod molluscs (snails). In this animal group, an early event of embryonic chirality controlled by cytoskeleton dynamics and the subsequent differential activation of the genes nodal and Pitx determine the left–right axis of snails, and thus the direction of coiling of the shell. Despite progressive advances in our understanding of left–right axis specification in molluscs, little is known about left–right development in other spiralian taxa. Here, we identify and characterize the expression of nodal and Pitx orthologues in three different spiralian animals—the brachiopod Novocrania anomala , the annelid Owenia fusiformis and the nemertean Lineus ruber —and demonstrate embryonic chirality in the biradial-cleaving spiralian embryo of the bryozoan Membranipora membranacea . We show asymmetric expression of nodal and Pitx in the brachiopod and annelid, respectively, and symmetric expression of Pitx in the nemertean. Our findings indicate that early embryonic chirality is widespread and independent of the cleavage programme in the Spiralia. Additionally, our study illuminates the evolution of nodal and Pitx signalling by demonstrating embryonic asymmetric expression in lineages without obvious adult left–right asymmetries. This article is part of the themed issue ‘Provocative questions in left–right asymmetry’.

scholarly journals Evolution and development of the adelphophagic, intracapsular Schmidt’s larva of the nemertean Lineus ruber

EvoDevo ◽  
2015 ◽  
Vol 6 (1) ◽  
Author(s):  
José M. Martín-Durán ◽  
Bruno C. Vellutini ◽  
Andreas Hejnol
Keyword(s):  
Evolution And Development ◽  
Lineus Ruber
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