The nicotinic acetylcholine receptor gene family of the silkworm, Bombyx mori

<p>Abstract</p> <p>Background</p> <p>Nicotinic acetylcholine receptors (nAChRs) mediate fast synaptic cholinergic transmission in the insect central nervous system. The insect nAChR is the molecular target of a class of insecticides, neonicotinoids. Like mammalian nAChRs, insect nAChRs are considered to be made up of five subunits, coded by homologous genes belonging to the same family. The nAChR subunit genes of <it>Drosophila melanogaster</it>, <it>Apis mellifera </it>and <it>Anopheles gambiae </it>have been cloned previously based on their genome sequences. The silkworm <it>Bombyx mori </it>is a model insect of Lepidoptera, among which are many agricultural pests. Identification and characterization of <it>B. mori </it>nAChR genes could provide valuable basic information for this important family of receptor genes and for the study of the molecular mechanisms of neonicotinoid action and resistance.</p> <p>Results</p> <p>We searched the genome sequence database of <it>B. mori </it>with the fruit fly and honeybee nAChRs by tBlastn and cloned all putative silkworm nAChR cDNAs by reverse transcriptase-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE) methods. <it>B. mori </it>appears to have the largest known insect nAChR gene family to date, including nine α-type subunits and three β-type subunits. The silkworm possesses three genes having low identity with others, including one α and two β subunits, α9, β2 and β3. Like the fruit fly and honeybee counterparts, silkworm nAChR gene α6 has RNA-editing sites, and α4, α6 and α8 undergo alternative splicing. In particular, alternative exon 7 of Bmα8 may have arisen from a recent duplication event. Truncated transcripts were found for Bmα4 and Bmα5.</p> <p>Conclusion</p> <p><it>B. mori </it>possesses a largest known insect nAChR gene family characterized to date, including nine α-type subunits and three β-type subunits. RNA-editing, alternative splicing and truncated transcripts were found in several subunit genes, which might enhance the diversity of the gene family.</p

Risk factors and management of hyperuricemia after renal transplantation

Hyperuricemia (HUA) is a common complication after renal transplantation. Currently, there is no uniform consensus on factors which increase the risk for and treatment of HUA in renal transplant recipients. The purpose of this review is to summarize current and proposed risk factors and strategies to manage HUA after renal transplantation in order to assist renal function protection and prolong graft survival time

Genome sequence and organization of a nucleopolyhedrovirus that infects the tea looper caterpillar, Ectropis obliqua

AbstractThe complete nucleotide sequence of Ectropis obliqua nucleopolyhedrovirus (EcobNPV), which infects the tea looper caterpillar, was determined and analyzed. The double stranded circular genome is composed of 131,204 bp and is 37.6% G+C rich. The analysis predicted 126 putative, minimally overlapping open reading frames (ORFs) with 150 or more nucleotides that together compose 89.8% of the genome. The remaining 10.2% constitute non-coding and three homologous regions. Comparison with previously sequenced baculoviruses indicated that three ORFs were unique to EcobNPV, while the remaining 123 ORFs shared identity with other baculovirus genes. In addition to two bro homologues, three other repeat ORFs, including dbp, p26, and odv-e66, were identified. Phylogenetic analysis indicated that each member of the paired ORFs was acquired independently. Gene parity plot analysis and percent identity of gene homologues suggested that EcobNPV is a Group II NPV, although its genomic organization was highly distinct

De novo intestine-specific transcriptome of the brown planthopper Nilaparvata lugens revealed potential functions in digestion, detoxification and immune response

AbstractThe brown planthopper (Nilaparvata lugens, BPH) is the most serious rice plant pests in Asia. In this study, we performed transcriptome-wide analysis on BPH intestine. We obtained more than 26 million sequencing reads that were then assembled into 53,553 unigenes with a mean size of 388bp. Based on similarity search with the nucleotide sequences available at NCBI, BPH intestine-specific transcriptome analysis identified 21,405 sequences. Assembled sequences were annotated with gene description, gene ontology and clusters of orthologous group terms. The digestion-, defense- and xenobiotic metabolism-related genes were abundantly detected in the transcripts from BPH intestine. Many novel genes including 33 digestion-related genes, 25 immune responsive genes and 27 detoxification-related genes are first reported here. We investigated the gene expression patterns at the transcript levels in different tissues by quantitative real-time PCR analysis, which revealed that some genes had intestine-specific expression, implicating their potential significance for BPH management

De novo characterization of a whitefly transcriptome and analysis of its gene expression during development

<p>Abstract</p> <p>Background</p> <p>Whitefly (<it>Bemisia tabaci</it>) causes extensive crop damage throughout the world by feeding directly on plants and by vectoring hundreds of species of begomoviruses. Yet little is understood about its genes involved in development, insecticide resistance, host range plasticity and virus transmission.</p> <p>Results</p> <p>To facilitate research on whitefly, we present a method for <it>de novo </it>assembly of whitefly transcriptome using short read sequencing technology (Illumina). In a single run, we produced more than 43 million sequencing reads. These reads were assembled into 168,900 unique sequences (mean size = 266 bp) which represent more than 10-fold of all the whitefly sequences deposited in the GenBank (as of March 2010). Based on similarity search with known proteins, these analyses identified 27,290 sequences with a cut-off E-value above 10^-5. Assembled sequences were annotated with gene descriptions, gene ontology and clusters of orthologous group terms. In addition, we investigated the transcriptome changes during whitefly development using a tag-based digital gene expression (DGE) system. We obtained a sequencing depth of over 2.5 million tags per sample and identified a large number of genes associated with specific developmental stages and insecticide resistance.</p> <p>Conclusion</p> <p>Our data provides the most comprehensive sequence resource available for whitefly study and demonstrates that the Illumina sequencing allows <it>de novo </it>transcriptome assembly and gene expression analysis in a species lacking genome information. We anticipate that next generation sequencing technologies hold great potential for the study of the transcriptome in other non-model organisms.</p