Haddock, S. H. | Search bioRxiv

bioRxiv2018

Luciferase of the Japanese syllid polychaete Odontosyllis umdecimdonta

1Odontosyllis undecimdonta is a marine syllid polychaete that produces bright internal and exuded bioluminescence. Despite over fifty years of biochemical investigation into Odontosyllis bioluminescence, the light-emitting small molecule substrate and catalyzing luciferase protein have remained a mystery. Here we describe the discovery of a bioluminescent protein fraction from O. undecimdonta, the identification of the luciferase using peptide and RNA sequencing, and the in vitro reconstruction of the bioluminescence reaction using highly purified O. undecimdonta luciferin and recombinant luciferase. Lastly, we found no identifiably homologous proteins in publicly available datasets. This suggests that the syllid polychaetes contain an evolutionarily unique luciferase among all characterized luminous taxa.\n\n3 HighlightsO_LIThe polychaete O. undecimdonta uses a luciferin-luciferase bioluminescence system\nC_LIO_LIO. undecimdonta bioluminescence does not require additional cofactors\nC_LIO_LIThe luciferase of the Japanese fireworm is 329 amino acids long\nC_LIO_LIRecombinant luciferase is not secreted when expressed in human cells\nC_LIO_LIExogenous luciferin does not seem to penetrate cell membranes-only lysate luminesces\nC_LIO_LIThe luciferase transcript is supported by full-length cDNA reads with 5 and 3 UTR\nC_LI\n\n\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=80 SRC=\"FIGDIR/small/329631_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (25K):\norg.highwire.dtl.DTLVardef@15882beorg.highwire.dtl.DTLVardef@1efc214org.highwire.dtl.DTLVardef@1aee561org.highwire.dtl.DTLVardef@15582b7_HPS_FORMAT_FIGEXP M_FIG C_FIG

biochemistry↗

bioRxiv2017

The Genome Of The Contractile Demosponge Tethya wilhelma And The Evolution Of Metazoan Neural Signalling Pathways

Porifera are a diverse animal phylum with species performing important ecological roles in aquatic ecosystems, and have become models for multicellularity and early-animal evolution. Demosponges form the largest class in sponges, but previous studies have relied on the only draft demosponge genome of Amphimedon queenslandica. Here we present the 125-megabase draft genome of a contractile laboratory demosponge Tethya wilhelma, sequenced to almost 150x coverage. We explore the genetic repertoire of transporters, receptors, and neurotransmitter metabolism across early-branching metazoans in the context of the evolution of these gene families. Presence of many genes is highly variable across animal groups, with many gene family expansions and losses. Three sponge classes show lineage-specific expansions of GABA-B receptors, far exceeding the gene number in vertebrates, while ctenophores appear to have secondarily lost most genes in the GABA pathway. Both GABA and glutamate receptors show lineage-specific domain rearrangements, making it difficult to trace the evolution of these gene families. Gene sets in the examined taxa suggest that nervous systems evolved independently at least twice and either changed function or were lost in sponges. Changes in gene content are consistent with the view that ctenophores and sponges are the earliest-branching metazoan lineages and provide additional support for the proposed clade of Placozoa/Cnidaria/Bilateria.

genomics↗