Characterization of nAChRs in Nematostella vectensis supports neuronal and non-neuronal roles in the cnidarian-bilaterian common ancestor.
by Kaitlin
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Background nicotinic acetylcholine receptors and muscarinic probably evolved in the ancestor of cnidarians-bilaterian. Both families of receptors are best known for their role in chemical synapses in bilaterian animals, but they also described the role as a non-neural receptor signaling in bilaterians. It is not clear when any of the functions for nicotinic or muscarinic receptors develop. Previous research in cnidarians show the role of acetylcholine nerve there before the divergence of cnidarians-bilaterian, but not discuss non-neuronal function potential.
To determine the origin function of neuronal and non-neuronal nicotinic acetylcholine receptors, we investigate the phylogenetic position of acetylcholine receptors cnidarians, characterized by spatiotemporal expression patterns in N. vectensis nicotinic receptors, and compared to pharmacological studies in N. vectensis to previous work in other cnidarians.
result Consistent with the activity described in other cnidarians, treatment with acetylcholine-induced contraction in cnidarians tentacular N. vectensis sea anemone. Phylogenetic analysis showed that the genome encodes 26 N. vectensis nicotinic (nAChRs) and no muscarinic (mAChRs) acetylcholine receptors and that an independent nAChRs linages radiated in cnidarians and bilaterian. Namesake nAChR agonist, nicotine, resulting tentacular contraction similar to that observed with acetylcholine, and the nAChR antagonist mecamylamine pressed tentacular contraction induced by both acetylcholine and nicotine. This indicates that the actual tentacle contraction mediated by nAChRs. Nicotine is also due to radial contraction of muscles, which contract as part of a peristaltic waves that propagate along the oral-aboral axis of the trunk. radial contraction and peristaltic waves suppressed by mecamylamine.
Characterization of nAChRs in Nematostella vectensis supports neuronal and non-neuronal roles in the cnidarian-bilaterian common ancestor.
The ability of nicotine to mimic acetylcholine response, and mecamylamine to suppress acetylcholine and nicotine-induced contraction, support neuronal function to acetylcholine in cnidarians. Examination of spatiotemporal expression of N. vectensis nAChRs (NvnAChRs) during development and juvenile polyps identified that NvnAChRs expressed in neurons, muscles, gonads, and large domains that are known to be consistent with a role in the development of the pattern. These patterns are consistent with the capacity of neuronal nAChRs well functioning and non-neuronal in N. vectensis.
Conclusion Our data indicate that nAChR receptor function at chemical synapses in N. vectensis to regulate contraction of the tentacles. similar responses to acetylcholine are well documented in cnidarians, showed that neural function is the ancestral role of nAChRs. nAChRs expression pattern consistent with the role of neuronal and non-neuronal to acetylcholine in cnidarians. Together, these observations suggest that the function of neuronal and non-neuronal nAChRs ancestors to be present in the ancestor of cnidarians-bilaterian.
Thus, the two roles are described in bilaterian species may appear at or near the base of the evolution of nAChR. hereditary colon tumors usually part of different syndromes that require management of both diseases intestinal and extra-intestinal. polyposis syndrome include: Familial adenomatous polyposis, MUTYH associated polyposis, serrated polyposis syndrome, Peutz-Jeghers syndrome, Juvenile polyposis syndrome and syndrome PTEN-hamartomatous.
Of all colorectal cancer (CRC), 5% -10% will be caused by hereditary CRC syndrome underlying. Diagnosis and management of polyposis syndromes continues to evolve as new scientific and technological advances are made in relation to identifying the causative gene and increased sophistication of endoscopic therapy for treating polyps. This, in addition to the data generated from the meticulous recording by registrants polyposis has helped to guide management in what is otherwise a relatively rare condition
