Analysis of cattle olfactory subgenome: the first detail study on the characteristics of the complete olfactory receptor repertoire of a ruminant.

BACKGROUND: Mammalian olfactory receptors (ORs) are encoded by the largest mammalian multigene family. Understanding the OR gene repertoire in the cattle genome could lead to link the effects of genetic differences in these genes to variations in olfaction in cattle. RESULTS: We report here a whole genome analysis of the olfactory receptor genes of Bos taurus using conserved OR gene-specific motifs and known OR protein sequences from diverse species. Our analysis, using the current cattle genome assembly UMD 3.1 covering 99.9% of the cattle genome, shows that the cattle genome contains 1,071 OR-related sequences including 881 functional, 190 pseudo, and 352 partial OR sequences. The OR genes are located in 49 clusters on 26 cattle chromosomes. We classified them into 18 families consisting of 4 Class I and 14 Class II families and these were further grouped into 272 subfamilies. Comparative analyses of the OR genes of cattle, pigs, humans, mice, and dogs showed that 6.0% (n = 53) of functional OR cattle genes were species-specific. We also showed that significant copy number variations are present in the OR repertoire of the cattle from the analysis of 10 selected OR genes. CONCLUSION: Our analysis revealed the almost complete OR gene repertoire from an individual cattle genome. Though the number of OR genes were lower than in pigs, the analysis of the genetic system of cattle ORs showed close similarities to that of the pig.

The complete swine olfactory subgenome: expansion of the olfactory gene repertoire in the pig genome.

BACKGROUND: Insects and animals can recognize surrounding environments by detecting thousands of chemical odorants. Olfaction is a complicated process that begins in the olfactory epithelium with the specific binding of volatile odorant molecules to dedicated olfactory receptors (ORs). OR proteins are encoded by the largest gene superfamily in the mammalian genome. RESULTS: We report here the whole genome analysis of the olfactory receptor genes of S. scrofa using conserved OR gene specific motifs and known OR protein sequences from diverse species. We identified 1,301 OR related sequences from the S. scrofa genome assembly, Sscrofa10.2, including 1,113 functional OR genes and 188 pseudogenes. OR genes were located in 46 different regions on 16 pig chromosomes. We classified the ORs into 17 families, three Class I and 14 Class II families, and further grouped them into 349 subfamilies. We also identified inter- and intra-chromosomal duplications of OR genes residing on 11 chromosomes. A significant number of pig OR genes (n = 212) showed less than 60% amino acid sequence similarity to known OR genes of other species. CONCLUSION: As the genome assembly Sscrofa10.2 covers 99.9% of the pig genome, our analysis represents an almost complete OR gene repertoire from an individual pig genome. We show that S. scrofa has one of the largest OR repertoires, suggesting an expansion of OR genes in the swine genome. A significant number of unique OR genes in the pig genome may suggest the presence of swine specific olfactory stimulation.

Genome data of shrimp acute hepatopancreatic necrosis disease causative Vibrio parahaemolyticus strains isolated from South Korea aquaculture farms.

The Vibrio parahaemolyticus is a gram-negative bacterium, which is responsible for acute hepatopancreatic necrosis disease (AHPND) in shrimp and has various virulent factors. So, to intensify the knowledge on pathogenic mechanism, the heterogeneous V.parahaemolyticus strains genome are indeed. Here, genome of seven V.parahaemolyticus strains, which are virulent to shrimps were sequenced by PacBio platform and the virulence was confirmed through the presence of plasmid (∼69 Kb) with binary toxin genes (i.e., pirA and pirB) with PCR method.

TISA: tissue-specific alternative splicing in human and mouse genes.

Alternative splicing (AS) is a mechanism by which multiple transcripts are produced from a single gene and is thought to be an important mechanism for tissue-specific expression of transcript isoforms. Here, we report a novel graphing method for transcript reconstruction and statistical prediction of tissue-specific AS. We applied three selection steps to generate the splice graph and predict the transcript isoforms: (i) a custom scoring rule for exon/intron sets, (ii) binomial statistics for selecting valid alternative splicing with a frequency of at least 1% for the predominant form and (iii) evaluation of transcript structure. We obtained 97 286 and 66 022 valid transcripts from 26 143 human and 27 741 mouse genes, respectively. In addition, we discovered 33 481 AS events for nine types of AS patterns in human. The statistical significance of tissue specificity for each gene, transcript and AS event was assessed based on EST tissue information, followed by a multiple testing correction procedure. In human, 12 711 genes, 16 016 transcripts and 1035 AS events were predicted to be tissue-specific (false discovery rate <0.01). This information on genes, transcript structures, AS events and their tissue specificities in human and mouse are freely accessible on the TISA website (http://tisa.kribb.re.kr/AGC/).

Minke whale genome and aquatic adaptation in cetaceans.

The shift from terrestrial to aquatic life by whales was a substantial evolutionary event. Here we report the whole-genome sequencing and de novo assembly of the minke whale genome, as well as the whole-genome sequences of three minke whales, a fin whale, a bottlenose dolphin and a finless porpoise. Our comparative genomic analysis identified an expansion in the whale lineage of gene families associated with stress-responsive proteins and anaerobic metabolism, whereas gene families related to body hair and sensory receptors were contracted. Our analysis also identified whale-specific mutations in genes encoding antioxidants and enzymes controlling blood pressure and salt concentration. Overall the whale-genome sequences exhibited distinct features that are associated with the physiological and morphological changes needed for life in an aquatic environment, marked by resistance to physiological stresses caused by a lack of oxygen, increased amounts of reactive oxygen species and high salt levels.

SpiroESTdb: a transcriptome database and online tool for sparganum expressed sequences tags.

BACKGROUND: Sparganum (plerocercoid of Spirometra erinacei) is a parasite that possesses the remarkable ability to survive by successfully modifying its physiology and morphology to suit various hosts and can be found in various tissues, even the nervous system. However, surprisingly little is known about the molecular function of genes that are expressed during the course of the parasite life cycle. To begin to decipher the molecular processes underlying gene function, we constructed a database of expressed sequence tags (ESTs) generated from sparganum. FINDINGS: SpiroESTdb is a web-based information resource that is built upon the annotation and curation of 5,655 ESTs data. SpiroESTdb provides an integrated platform for expressed sequence data, expression dynamics, functional genes, genetic markers including single nucleotide polymorphisms and tandem repeats, gene ontology and KEGG pathway information. Moreover, SpiroESTdb supports easy access to gene pages, such as (i) curation and query forms, (ii) in silico expression profiling and (iii) BLAST search tools. Comprehensive descriptions of the sparganum content of all sequenced data are available, including summary reports. The contents of SpiroESTdb can be viewed and downloaded from the web (http://pathod.cdc.go.kr/spiroestdb). CONCLUSIONS: This integrative web-based database of sequence data, functional annotations and expression profiling data will serve as a useful tool to help understand and expand the characterization of parasitic infections. It can also be used to identify potential industrial drug targets and vaccine candidate genes.