(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 > Bilateria: NE > Protostomia: NE > Ecdysozoa: NE > Panarthropoda: NE > Arthropoda: NE > Mandibulata: NE > Pancrustacea: NE > Hexapoda: NE > Insecta: NE > Dicondylia: NE > Pterygota: NE > Neoptera: NE > Holometabola: NE > Hymenoptera: NE > Apocrita: NE > Aculeata: NE > Apoidea: NE > Apidae: NE > Apinae: NE > Apini: NE > Apis: NE > Apis mellifera: 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 MSRMLRLELVGLVLLACTQILTEHRNIYETRPVYGYRSKFLDPPERFTRE VRVKQGRLRGIVVQPRTNHDLQPVDVFLGVPYAEPPVNFLRFSPPRSPEP WRGTRESQEFAPVCPQVVPKLQDEMKPVRYEYLERLLPYLKNQSEDCLYL NIYTPHQPEGQKTLRKYPVMVFIHGESFEWNSGNPYDGTILAAYGNVVFV TISFRLGILGFLRPGIRDDTASNFGLLDQIAALLWLRENIAEFGGDPNSI TLVGHGTGAIFANLLLISPVANKKGLFRRAILMSGSALSADAIGKAPLQI TKQVAHALHCPTTTDSDLAICLRGQDVDTLLNVKIHKPSYVPAFAPLIDN AVIPDKPYNLMKNPQMFDRFDQMYGVTESEKYHLLSPVDLMHGMSEGQRD AVLKEHAKATHELEAELILSKILEQYGDFSPGFQGEYMLKNRDLVLEALS DSGTAAPLIMAANLHSRANPNSYMYVFAHPKATQEYSGQQRKYTVHSEEL PYLLGAPLDGLRGRYDIGGTLFSEAIMNWWCSFAYIGNPNVKAISKRYPY MRNGLKELSQYDIDWPEYDPQNQRYLNLTIPPSTGMQYRLAEMQFWSEHL PKMLLHPGKDIPLPIRPKGPRPQIPDIADGIGKYAYASRDYDTYGSRFKE GSRSGAEAGITAEERSTTSEIATSPQSLEEEAIAQPSAPKSSSVIAMLTG FGALFLLINFTACLYLYCKKQETKMKGAGVKRRASQKEAESDRYENHYGE LGYKSDSKPDLNDVIKNDKAYDNNSNFGRRSKLSRQSSGSTIDTHIKVRE WIQQEIVHR
Vertebrate studies show neuroligins and neurexins are binding partners in a trans-synaptic cell adhesion complex, implicated in human autism and mental retardation disorders. Here we report a genetic analysis of homologous proteins in the honey bee. As in humans, the honeybee has five large (31-246 kb, up to 12 exons each) neuroligin genes, three of which are tightly clustered. RNA analysis of the neuroligin-3 gene reveals five alternatively spliced transcripts, generated through alternative use of exons encoding the cholinesterase-like domain. Whereas vertebrates have three neurexins the bee has just one gene named neurexin I (400 kb, 28 exons). However alternative isoforms of bee neurexin I are generated by differential use of 12 splice sites, mostly located in regions encoding LNS subdomains. Some of the splice variants of bee neurexin I resemble the vertebrate alpha- and beta-neurexins, albeit in vertebrates these forms are generated by alternative promoters. Novel splicing variations in the 3' region generate transcripts encoding alternative trans-membrane and PDZ domains. Another 3' splicing variation predicts soluble neurexin I isoforms. Neurexin I and neuroligin expression was found in brain tissue, with expression present throughout development, and in most cases significantly up-regulated in adults. Transcripts of neurexin I and one neuroligin tested were abundant in mushroom bodies, a higher order processing centre in the bee brain. We show neuroligins and neurexins comprise a highly conserved molecular system with likely similar functional roles in insects as vertebrates, and with scope in the honeybee to generate substantial functional diversity through alternative splicing. Our study provides important prerequisite data for using the bee as a model for vertebrate synaptic development.
The honeybee genome has substantially fewer protein coding genes ( approximately 11 000 genes) than Drosophila melanogaster ( approximately 13 500) and Anopheles gambiae ( approximately 14 000). Some of the most marked differences occur in three superfamilies encoding xenobiotic detoxifying enzymes. Specifically there are only about half as many glutathione-S-transferases (GSTs), cytochrome P450 monooxygenases (P450s) and carboxyl/cholinesterases (CCEs) in the honeybee. This includes 10-fold or greater shortfalls in the numbers of Delta and Epsilon GSTs and CYP4 P450s, members of which clades have been recurrently associated with insecticide resistance in other species. These shortfalls may contribute to the sensitivity of the honeybee to insecticides. On the other hand there are some recent radiations in CYP6, CYP9 and certain CCE clades in A. mellifera that could be associated with the evolution of the hormonal and chemosensory processes underpinning its highly organized eusociality.
