Characterization of <Emphasis Type="Italic">Francisella</Emphasis> sp., GM2212, the first <Emphasis Type="Italic">Francisella</Emphasis> isolate from marine fish,Atlantic cod (<Emphasis Type="Italic">Gadus morhua</Emphasis>)

A Francisella sp., isolate GM2212^T, previously isolated from diseased farmed Atlantic cod Gadus morhua in Norway is characterized. The complete 16S rDNA, 16S–23S intergenic spacer, 23S rDNA, 23S–5S intergenic spacer, 5S rDNA, FopA, lipoprotein TUL4 (LpnA), malate dehydrogenase and a hypothetical lipoprotein (LpnB) is sequenced and compared with Francisella tularensis and Francisella philomiragia. All these sequences support a close relationship between GM2212^T and F. philomiragia. The bacterium grows at 10–25°C with an optimum at about 20°C, a temperature range clearly different from F. tularensis and F. philomiragia. GM2212^T is catalase-positive, indole positive, oxidase-negative, do not produce H₂S in Triple Sugar Iron agar, and does not hydrolyze gelatin, is resistant to erythromycin and susceptible to ceftazidime, the latter five characteristics separating it from F. philomiragia. Cysteine enhances growth. Acid is produced from d-glucose, maltose, sucrose (weak) but not from lactose or glycerol. GM2212^T grows on both MacConkey agar and in nutrient broth (6% NaCl). The bacterium is resistant to trimethoprim-sulfamethoxazole, penicillines, cefuroxime and erythromycin; but is susceptible to ceftazidime, tetracycline, gentamicin, ciprofloxacin. Based on the molecular and phenotypical characteristics, we suggest that this GM2212 isolate, may represent a new species of Francisella. Isolate GM2212^T (=CNCM I-3481^T = CNCM I-3511^T = DSM 18777^T).     

Identification and characterisation of nine new gene-associated microsatellite markers for Atlantic cod (<Emphasis Type="Italic">Gadus morhua</Emphasis> L.)

Nine polymorphic microsatellite markers were identified by screening of 2464 ESTs derived from a cDNA library of Atlantic cod (Gadus morhua L.). About 35 novel microsatellite loci were selected and characterised in 96 individual cod. Nine markers were successfully amplified with number of alleles from 3 to 18 per locus and the average heterozygosity was 0.57 in the panel examined (range 0.29–0.86). All loci followed the Hardy–Weinberg expectation and no significant linkage disequilibrium was found in a test including all pairwise combinations. The gene identity was determined at four of the loci, confirming the associated microsatellites as Type I markers.     

Population variation in thermal growth responses of juvenile Atlantic cod (<Emphasis Type="Italic">Gadus morhua</Emphasis> L.)

Controlled environment experiments were carried out to investigate thermal influences and population differences on growth of wild-caught juvenile Atlantic cod Gadus morhua L. from two regions of differing thermal regime off Scotland; the Clyde Sea on the west coast and St Andrews Bay on the east coast. Cod from the Clyde demonstrated significantly higher growth rates than cod from St Andrews. In both populations the growth rate was greater at 12°C than at 8°C. These population and temperature effects act to reinforce one another and it could therefore be predicted that the growth differences between the two areas in the wild should be even more pronounced. The results are consistent with the suggestion that cod may be locally adapted to their thermal environment.     

The Diversity of Bacterial Communities Associated with Atlantic Cod <Emphasis Type="Italic">Gadus morhua</Emphasis>

The spatial and temporal changes in the bacterial communities associated with the Atlantic cod Gadus morhua were investigated using terminal restriction fragment length polymorphism (T-RFLP) analysis of 16S recombinant DNA (rDNA). Epidermal mucous was sampled from 366 cod caught in three harvest locations (Baltic, Icelandic, and North Seas) over three seasons (spring 2002, autumn 2002, and spring 2003), and an automated method for the high-throughput processing of environmental samples was developed using a Qiagen BioRobot. The analysis revealed that a diverse consortium of bacteria were found on fish; γ-proteobacteria and Cytophaga–Flavobacter–Bacteroides (CFB) species were dominant. T-RFLP peak profiles suggested that operational taxonomic units (OTUs) related to Photobacterium sp., Psychrobacter sp., and Bacteroides sp. were common to all sites in all three seasons, but there were intersite variations in community composition. Cod caught from different seas had distinct reproducible bacterial assemblages. Whereas communities from fish caught in the Baltic and Icelandic Seas were relatively stable over the three seasons, those from fish from the North Sea changed significantly over time.     

Domestication causes rapid changes in heart and brain morphology in Atlantic cod (<Emphasis Type="Italic">Gadus morhua</Emphasis>)

Brain and heart development is very plastic in teleost fishes, and receptive to changes in social and environmental conditions. Domestication in salmonids has been reported to result in pronounced changes in both heart and brain morphology. In particular, a high prevalence of heart deformities has been reported in farmed salmonids, which has been linked to increased stress responsiveness that can impair survival of both farmed and escaped fish. Here we report for the first time that significant changes in heart and brain morphology occur following domestication of Atlantic cod (Gadus morhua), an emerging aquaculture species. Juvenile farmed cod developed significantly larger hearts and smaller brains, by weight, compared to their wild conspecifics. These differences occurred within the first captive generation, suggesting that they were driven largely by the strong contrast in environmental and social conditions experienced within their respective rearing environments. Changes in brain and heart morphology, as a consequence of domestication could affect the well-being and survival of Atlantic cod raised under intensive aquaculture conditions.     

Occurrence of the tuna nematode <Emphasis Type="Italic">Hysterothylacium cornutum</Emphasis> (Stossich, 1904) in farmed Atlantic cod <Emphasis Type="Italic">Gadus morhua</Emphasis> L. in North Norway

Adult and fourth-stage larval nematodes found in the stomachs of farmed cod in North Norway in October 2006 were identified as Hysterothylacium cornutum (Stossich, 1904), a nematode considered to be specific at the adult stage to tunas of the genus Thunnus. As far as we are aware, this is the first report of an adult form of this nematode from any host other than members of the genus Thunnus, and is also the first report from a polar region. The two infected cod, one with one large adult worm and another with six larvae, were in a sample of 17 that had been captured from the wild about 1 year before sampling and held in floating sea cages in Øksfjord, Finnmark County, North Norway, where the examinations took place. No further infections were found in any other samples of wild and farmed cod, totalling 261 fish, examined by us during the period 2006 and 2007 from five locations distributed along the coast of Norway from Øksfjord in the north to Ålesund in the south. Possible sources of this unusual infection are discussed, but no firm conclusion could be reached.     

Atlantic cod <Emphasis Type="Italic">Gadus morhua</Emphasis> (Gadiformes: Gadidae) from the Gulf of Ura: Morphobiological characteristic

Analysis of variation of biological and morphometric characteristics of cod Gadus morhua from the Gulf of Ura-a water area in the composition of Motovskii Bay of the Barents Sea was performed. The material was collected from 1999 to 2006 during spawning of the Atlantic cod. Parameters such as length, weight, sex composition, maturity stage, age, otolith structure, and variation of plastic characters were analyzed. It was shown that the Gulf of Ura, parallel to individuals of junior age groups, is inhabited by cod in the spawning state aged 5–6 months and older with coastal and Atlantic types of otolith.     

Preliminary data on the variability of three microsatellite loci in Pacific <Emphasis Type="Italic">Gadus macrocephalus</Emphasis> and Atlantic <Emphasis Type="Italic">G. morhua</Emphasis> cod (Gadidae)

Variability of microsatellite DNA loci Gmo3, Gmo34, and Gmo35 is studied in samples of Pacific cod Gadus macrocephalus and Atlantic cod G. morhua. The results show high values of identity of the samples within the North Pacific basin (0.9766–0.9924) and within the Northeast Atlantic basin (0.9580). Based on the pairwise assessment of genetic differentiation, the F _ST values are significantly different in all variants between the samples of Pacific and Atlantic cod (F _ST = 0.5235–0.6719, p < 0.001). Within the basins, the significant differences in the frequencies of main alleles are revealed in the loci Gmo3 and Gmo34 for the samples from the Pacific and Atlantic oceans, respectively.     

Identification,cloning and characterization of <Emphasis Type="Italic">sis7</Emphasis> and <Emphasis Type="Italic">sis10</Emphasis> sugar-insensitive mutants of <Emphasis Type="Italic">Arabidopsis</Emphasis>

Background  

The levels of soluble sugars, such as glucose and sucrose, help regulate many plant metabolic, physiological and developmental processes. Genetic screens are helping identify some of the loci involved in plant sugar response and reveal extensive cross-talk between sugar and phytohormone response pathways.     

Environmental assessment of cod (<Emphasis Type="BoldItalic">Gadus morhua</Emphasis>) from autoline fisheries

Purpose  

The main purpose of this study has been to document the environmental performance of products based on autoline-caught cod and the distribution of environmental impacts in the value chain from fishing to retail. Another aim has been to document the performed environmental improvement analyses.     

The effect of food odor background on gustatory preferences and gustatory behavior of carp <Emphasis Type="Italic">Cyprinus carpio</Emphasis> and cod <Emphasis Type="Italic">Gadus morhua</Emphasis>

It was shown that stimulation by food odor (aquatic extract of food organisms, 10^?2 and 10^?3 g/l) does not cause shifts in gustatory preferences in carp Cyprinus carpio and cod Gadus morhua but modifies gustatory behavior. The level of consumption by carp of control granules and granules with attractive, by taste, L-proline (0.1 M) or deterrent L-lysine (0.1 M) (item by item presentation of granules) and by cod of control granules and granules with indifferent, to it, L-asparagine (0.1 M) (presentation of 10 granules simultaneously) is similar prior to and during olfactory stimulation. In the presence of food odor, the duration of taste testing for most types of granules, as well as the number of repeated graspings of granules with an attractive taste do not change in fish. At the same time, granules with indifferent or repulsive gustatory properties are rejected and repeatedly grasped by fish against the background of food odor more frequently than in water without odor. Olfactory stimulation leads to a considerable increase in the average number of graspings per one grasped granule with an indifferent or repulsive taste. Such behavior manifested by fish in the presence of food odor in response to granules with unattractive gustatory properties is apparently caused by the contradiction between the information coming via different chemosensory canals—olfactory and gustatory. The obtained results indicate that food stimulation caused by food odor in nature can lead to an increase in the actual consumption of only those accessible food items that have an attractive taste for fish.     

New species in the genus <Emphasis Type="Italic">Francisella</Emphasis> (Gammaproteobacteria; Francisellaceae); <Emphasis Type="Italic">Francisella piscicida</Emphasis> sp. nov. isolated from cod (<Emphasis Type="Italic">Gadus morhua</Emphasis>)

A Francisella strain, GM2212, previously isolated from moribund farmed Atlantic cod (Gadus morhua) in Norway, is closely related to Francisella philomiragia among Francisella spp. according to its complete 16S rDNA, 16S-23S intergenic spacer, 23S rDNA, 23S–5S intergenic spacer, 5S rDNA, FopA, lipoprotein TUL4 (LpnA), malate dehydrogenase and hypothetical lipoprotein (LpnB) sequences. A comparison between GM2212 and the type strain of Francisella philomiragia were performed by DNA–DNA hybridization and fatty acid analysis. The DNA–DNA hybridization showed a 70% similarity. The fatty acid analysis showed only minor differences between the Francisella isolates. Due to the inconclusive result from the DNA–DNA hybridisation, major emphasis concerning the status of this isolate is made on previously published molecular, phenotypic and biochemical characters. All characteristics taken together support the establishment of GM2212 as a novel species, for which the name Francisella piscicida sp. nov. is proposed (=CNCM I-3511^T = DSM 18777^T = LMG registration number not yet available).     

Identification,characterization, and expression of the <Emphasis Type="Italic">SWEET</Emphasis> gene family in <Emphasis Type="Italic">Phalaenopsis equestris</Emphasis> and <Emphasis Type="Italic">Dendrobium officinale</Emphasis>

Sugars are important molecules that function not only as primary metabolites, but also as nutrients and signal molecules in plants. The sugar transport protein genes family SWEET has been recently identified. The availability of the Dendrobium officinale and Phalaenopsis equestris genome sequences offered the opportunity to study the SWEET gene family in this two orchid species. We identified 22 and 16 putative SWEET genes, respectively, in the genomes of D. officinale and P. equestris using comprehensive bioinformatics analysis. Based on phylogenetic comparisons with SWEET proteins from Arabidopsis and rice, the DoSWEET and PeSWEET proteins could be divided into four clades; among these, clade II specifically lacked PeSWEETs and clade IV specifically lacked DoSWEETs, and there were orthologs present between D. officinale and P. equestris. Protein sequence alignments suggest that there is a predicted serine phosphorylation site in each of the highly conserved MtN3/saliva domain regions. Gene expression analysis in four tissues showed that three PeSWEET genes were most highly expressed in the flower, leaf, stem, and root, suggesting that these genes might play important roles in growth and development in P. equestris. Analysis of gene expression in different floral organs showed that five PeSWEET genes were highly expressed in the column (gynostemium), implying their possible involvement in reproductive development in this species. The expression patterns of seven PeSWEETs in response to different abiotic stresses showed that three genes were upregulated significantly in response to high temperature and two genes were differently expressed at low temperature. The results of this study lay the foundation for further functional analysis of SWEET genes in orchids.     

New encounters in Arctic waters: a comparison of metabolism and performance of polar cod (<Emphasis Type="Italic">Boreogadus saida</Emphasis>) and Atlantic cod (<Emphasis Type="Italic">Gadus morhua</Emphasis>) under ocean acidification and warming

Oceans are experiencing increasing acidification in parallel to a distinct warming trend in consequence of ongoing climate change. Rising seawater temperatures are mediating a northward shift in distribution of Atlantic cod (Gadus morhua), into the habitat of polar cod (Boreogadus saida), that is associated with retreating cold water masses. This study investigates the competitive strength of the co-occurring gadoids under ocean acidification and warming (OAW) scenarios. Therefore, we incubated specimens of both species in individual tanks for 4 months, under different control and projected temperatures (polar cod: 0, 3, 6, 8 °C, Atlantic cod: 3, 8, 12, 16 °C) and PCO₂ conditions (390 and 1170 µatm) and monitored growth, feed consumption and standard metabolic rate. Our results revealed distinct temperature effects on both species. While hypercapnia by itself had no effect, combined drivers caused nonsignificant trends. The feed conversion efficiency of normocapnic polar cod was highest at 0 °C, while optimum growth performance was attained at 6 °C; the long-term upper thermal tolerance limit was reached at 8 °C. OAW caused only slight impairments in growth performance. Under normocapnic conditions, Atlantic cod consumed progressively increasing amounts of feed than individuals under hypercapnia despite maintaining similar growth rates during warming. The low feed conversion efficiency at 3 °C may relate to the lower thermal limit of Atlantic cod. In conclusion, Atlantic cod displayed increased performance in the warming Arctic such that the competitive strength of polar cod is expected to decrease under future OAW conditions.     

Molecular cloning and expression analysis of <Emphasis Type="Italic">Bmrbp1</Emphasis>, the <Emphasis Type="Italic">Bombyx mori</Emphasis> homologue of the <Emphasis Type="Italic">Drosophila</Emphasis> gene <Emphasis Type="Italic">rbp1</Emphasis>

RBP1 is an important splicing factor involved in alternative splicing of the pre-mRNA of Drosophila sex-determining gene dsx. In this work, the Bombyx mori homologue of the rbp1 gene, Bmrbp1, was cloned. The pre-mRNA of Bmrbp1 gene is alternatively spliced to produce four mature mRNAs, named Bmrbp1-PA, Bmrbp1-PB, Bmrbp1-PC and Bmrbp1-PD, with nucleotide lengths of 799 nt, 1,316 nt, 894 nt and 724 nt, coding for 142 aa, 159 aa, 91 aa and 117 aa, respectively. BmRBP1-PA and BmRBP1-PD contain a N terminal RNA recognization motif (RRM) and a C terminal arginine/serine-rich domain, while BmRBP1-PB and BmRBP1-PC only share a RRM. Amino acid sequence alignments showed that BmRBP1 is conserved with its homologues in other insects and with other SR family proteins. The RT-PCR showed that Bmrbp1-PA was strongly expressed in all examined tissues and development stages, but Bmrbp1-PB was weakly expressed in these tissues and stages. The expression of both Bmrbp1-PA and Bmrbp1-PB showed no obvious sex difference. While the Bmrbp1-PC and Bmrbp1-PD were beyond detection by RT-PCR very likely due to their tissue/stage specificity. These results suggested that Bmrbp1 should be a member of SR family splicing factors, whether it is involved in the sex-specific splicing of Bmdsx pre-mRNA needs further research.     

<Emphasis Type="Italic">Ty</Emphasis>1<Emphasis Type="Italic">/copia</Emphasis>- and <Emphasis Type="Italic">Ty</Emphasis>3<Emphasis Type="Italic">/gypsy</Emphasis>-like DNA sequences in <Emphasis Type="Italic">Helianthus </Emphasis>species

Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes.     

Molecular cloning,characterization and expression analysis of <Emphasis Type="Italic">Cm</Emphasis>APX

The RT PCR and RACE methods were used to obtain the cDNA sequence of an APX gene of muskmelon after the leaves were induced with powdery mildew. The cDNA length of the APX gene is 1,047 bp with a 750 bp ORF encoded a 249 amino acid and the molecular weight of APX protein is 27.3 kDa. The analysis showed that the CmAPX genomic DNA contained 10 extrons and 9 introns. The identity of the amino acid sequence deduced from the cDNA with the APX family of other homologous members was about 74–97%. A Full-length of ORF was sub-cloned into prokaryotic expression vector pET24a. The recombinant proteins had high expression level in E. coli. Analysis of expression at mRNA level showed that CmAPX exhibited highly tissue-specific patterns of expression. The mRNA level and enzyme activities assays showed that CmAPX might play an important role in the pathogenesis of powdery mildew.