(Below N is a link to NCBI taxonomic web page and E link to ESTHER at designed phylum.) > cellular organisms: NE > Eukaryota: NE > Opisthokonta: NE > Metazoa: NE > Eumetazoa: NE > Cnidaria: NE > Hydrozoa: NE > Hydroidolina: NE > Leptothecata: NE > Campanulariidae: NE > Clytia: NE > Clytia hemisphaerica: NE
LegendThis sequence has been compared to family alignement (MSA) red => minority aminoacid blue => majority aminoacid color intensity => conservation rate title => sequence position(MSA position)aminoacid rate Catalytic site Catalytic site in the MSA RSTKLSKKMKVKLQRKLLLFTILCVHITSTFAVPQNRIPDADRDYVNIDT ECGPVEGKRFTENVKWHNDSVNVYEFRNIPYAKPPVGKLRWRPPVRLSDD PAQCWDGVLKYNKNVVACKQDHPFTPSVNTSEDCLVLTVRTPNLDPSSKL PVIVWIHGGGMLWGYNEMFAFHPDTEFSAYMEAVTVSINYRLNVFGFMSL KELWIENGPNKSYGNYGILDQIETLKWVKSNIKQFGGDSENVMIYGESGG GTGVYCLLCSPLANGLFQKASPQSGAPNIRTTHEVADMKYRSIIDKADCQ KESPDNIVECLQNIDADDFLSLFKGTSVTPYHWKMPTNEPYNGYPVEILD PVVVTKSPDQIPVHQNTQVELLIGNCAQETGPFPHKPKPDANITTWADLQ AALEPQMDTFKKGHYPHFLDQYQNDLKSPPQNITPKYVYEVMTSDALVLC TTNYVADHLSKVKGYTVSRYVMSQPPTKEIGLGLETAYHGWDSVLLFGLK FYKR
Jellyfish (medusae) are a distinctive life-cycle stage of medusozoan cnidarians. They are major marine predators, with integrated neurosensory, muscular and organ systems. The genetic foundations of this complex form are largely unknown. We report the draft genome of the hydrozoan jellyfish Clytia hemisphaerica and use multiple transcriptomes to determine gene use across life-cycle stages. Medusa, planula larva and polyp are each characterized by distinct transcriptome signatures reflecting abrupt life-cycle transitions and all deploy a mixture of phylogenetically old and new genes. Medusa-specific transcription factors, including many with bilaterian orthologues, associate with diverse neurosensory structures. Compared to Clytia, the polyp-only hydrozoan Hydra has lost many of the medusa-expressed transcription factors, despite similar overall rates of gene content evolution and sequence evolution. Absence of expression and gene loss among Clytia orthologues of genes patterning the anthozoan aboral pole, secondary axis and endomesoderm support simplification of planulae and polyps in Hydrozoa, including loss of bilateral symmetry. Consequently, although the polyp and planula are generally considered the ancestral cnidarian forms, in Clytia the medusa maximally deploys the ancestral cnidarian-bilaterian transcription factor gene complement.
Title: Acetylcholinesterase activity in Clytia hemisphaerica (Cnidaria) Denker E, Chatonnet A, Rabet N Ref: Chemico-Biological Interactions, 175:125, 2008 : PubMed
Cholinesterase activity is known in representatives of all living organisms phyla but the origin of the cholinergic system as known in bilaterian animals is still undeciphered. In particular the implication of cholinesterases in the nervous system of non-bilaterian Metazoa is not well known. We thus chose to investigate this activity in the Clytia hemisphaerica (Cnidaria) medusa. In toto histochemical staining revealed an acetylcholinesterase activity in the tentacle bulbs but not in the nervous system. Sequences homologous to acetylcholinesterase were searched within Clytia ESTs and compared to other sequences found in public databases.
