dc.contributor.author | Lin, Ming | |
dc.date.accessioned | 2017-12-18T14:25:41Z | |
dc.date.available | 2017-12-18T14:25:41Z | |
dc.date.issued | 2017-09-27 | |
dc.date.submitted | 2017-12-18T12:07:23.929Z | |
dc.identifier.citation | Li, M. 2017. Identification and functional characterization of relaxin-type and pedal peptide/orcokinin-type neuropeptides in the starfish Asterias rubens. Queen Mary University of London | en_US |
dc.identifier.uri | http://qmro.qmul.ac.uk/xmlui/handle/123456789/30715 | |
dc.description | PhD | en_US |
dc.description.abstract | Neuropeptides are neuronal signaling molecules that regulate many
physiological and behavioural processes in vertebrates and invertebrates. Investigation
of neuropeptide signaling in echinoderms (e.g. starfish) can provide insights into the
evolution of neuropeptide systems because as deuterostomian invertebrates they occupy
an “intermediate” phylogenetic position between vertebrates and protostomian
invertebrates. Recent analysis of neural transcriptome data from the starfish Asterias
rubens has identified 40 transcripts encoding neuropeptide precursors. Here the
expression and function of neuropeptides derived from four of these precursors was
investigated: relaxin-like gonad-stimulating peptide precursor (AruRGPP), relaxin-like
peptide precursor 2 (AruRLPP2), pedal peptide-like neuropeptide precursors 1 and 2
(ArPPLNP1 and ArPPLNP2).
AruRGP induces spawning of ovarian fragments from A. rubens. Analysis of the
expression of AruRGPP in A. rubens using mRNA in situ hybridization revealed
expression by cells in the radial nerve cords, circumoral nerve ring and tube feet.
Furthermore, a band of AruRGPP-expressing cells was also identified in the body wall
epithelium lining the cavity that surrounds the sensory terminal tentacle and optic
cushion at the tips of the arms. Discovery of these cells is important because they are
candidate physiological mediators for hormonal control of starfish spawning in response
to environmental cues. Interestingly, AruRLPP2 is also expressed in the same region of
the arm tip as AruRGPP but the physiological role(s) of AruRLP2 is not yet known.
Analysis of the expression of ArPPLNP1 and ArPPLNP2 using mRNA in situ
hybridization revealed a widespread pattern of expression in A. rubens. Furthermore,
immunohistochemical localization of peptides derived from these precursors revealed
immunostaining in neuronal processes innervating muscles. Consistent with this pattern
of expression, peptides derived from ArPPLNP1 and ArPPLNP2 act as muscle relaxants
in starfish. Interestingly, this contrasts with previous findings from protostomian
invertebrates, where pedal peptide/orcokinin-type neuropeptides act as muscle
contractants. | en_US |
dc.language.iso | en | en_US |
dc.publisher | Queen Mary University of London | en_US |
dc.rights | The copyright of this thesis rests with the author and no quotation from it or information derived from it may be published without the prior written consent of the author | |
dc.subject | Biological and Chemical Sciences | en_US |
dc.subject | Starfish | en_US |
dc.subject | Asterias rubens | en_US |
dc.subject | neuropeptides | en_US |
dc.subject | neuropeptide signaling | en_US |
dc.title | Identification and functional characterization of relaxin-type and pedal peptide/orcokinin-type neuropeptides in the starfish Asterias rubens | en_US |
dc.type | Thesis | en_US |