Taste attractiveness of free amino acids for juveniles of Persian sturgeon <Emphasis Type="Italic">Acipenser persicus</Emphasis>

Taste preferences towards 20 free amino acids (L-isomers, 0.1–0.0001 M) were determined in juveniles of Persian sturgeon Acipenser persicus. It was found that most amino acids (16) had a positive effect on extraoral gustatory reception (increased the frequency of catching artificial pellets by fishes). The most efficient amino acids were the following: threonine, histidine, arginine, asparagine, phenylalanine, cysteine, glutamine, and glycine. Fifteen amino acids were efficient for intraoral gustatory receptors: serine, arginine, cysteine, histidine, alanine, and some others. The presence of these amino acids in pellets increased the consumption. Amino acids decreasing the frequency of catching or consumption of pellets were not found. Highly significant positive correlation was found between the amino acid ranges mediated by the extraoral and intraoral gustatory reception. The fishes demonstrated maximum sensitivity to aspartic acid, 0.01 and 0.001 M, respectively, for intraoral and extraoral gustatory systems. The threshold concentrations of arginine and glycine were higher for the intraoral gustatory system (0.01 M) than for the extraoral one (0.1 M). The comparison of Persian sturgeon with sturgeon fishes (Russian sturgeon A. gueldenstaedtii, Siberian sturgeon A, baerii, and starred sturgeon A. stellatus) studied earlier confirmed high species specificity of intraoral taste preferences in representatives of Acipenser genus. Species specificity of extraoral taste ranges was less pronounced.     

Metallothionein as Potential Biomarker of Cadmium Exposure in Persian Sturgeon (<Emphasis Type="Italic">Acipenser persicus</Emphasis>)

Metallothionein (MT) concentration in gills, liver, and kidney tissues of Persian sturgeon (Acipenser persicus) were determined following exposure to sublethal levels of waterborne cadmium (Cd) (50, 400, and 1,000 μg l⁻¹) after 1, 2, 4, and 14 days. The increases of MT from background levels were 4.6-, 3-, and 2.8-fold for kidney, liver, and gills, respectively. The results showed that MT level change in the kidney is time and concentration dependent. Also, cortisol measurement revealed elevation at the day 1 of exposure and followed by MT increase in the liver. Cd concentrations in the cytosol of experimental tissues were measured, and the results indicated that Cd levels in the cytosol of liver, kidney, and gills increased 240.71-, 32.05-, and 40.16-fold, respectively, 14 days after exposure to 1,000 μg l⁻¹ Cd. The accumulation of Cd in cytosol of tissues is in the order of liver > gills > kidney. Pearson correlation coefficients showed that the MT content in kidney is correlated with Cd concentration, the value of which is more than in liver and gills. Thus, kidney can be considered as a tissue indicator in A. persicus for waterborne Cd contamination.     

Diet composition of the Persian sturgeon <Emphasis Type="Italic">Acipenser persicus</Emphasis> at the coast of the Guilan Province,Caspian Sea

Sturgeons are one of the most important and valuable species in the Caspian Sea. This investigation (2000–2002) was aimed at determining the feeding habits and the main and secondary prey organisms consumed by the Persian sturgeon (Acipenser persicus Borodin, 1897) living at depths less than 10 m in the Caspian Sea (Guilan Province). The food spectrum of immature A. persicus was comprised of benthic invertebrates of seven genera and fishes of three genera. The main prey items of immature A. persicus were polychaete worms and the secondary prey were crustaceans. The study of stomach contents showed that polychaetes were the most important component of the diet of immature A. persicus of the length class up to 25 cm.     

Influence of Insecticides Diazinon and Endosulfan on Taste Reception in Persian Sturgeon <Emphasis Type="Italic">Acipenser persicus</Emphasis> (Acipenseridae)

The present paper studies the effects of sublethal concentrations of two neurotoxic insecticides (diazinon and endosulfan, duration of exposure 48 h) on the taste attractiveness of L-histidine (0.1 M), L-cysteine (0.1 M), and L-asparagine acid (0.01 M) for juvenile Persian sturgeon Acipenser persicus. The study revealed different effects of diazinon and endosulfan on the extraoral and intraoral taste reception in fish. The taste responses determined by the extraoral taste system (frequency of grasping of 50 food pellets for 5 min of trial) following exposure to endosulfan are the same as in the intact specimens. The exposure to diazinon leads to two to fourfold increase in the number of grasping the pellets, while the amino acids become tasteattractive as opposed to the intact specimens. Both insecticides affect the taste responses controlled by the intraoral taste reception. The insecticide-related pathology is expressed either as a sharp (tens of times) decrease in the absolute and relative consumption of all types of pellets or as full rejection of the pellets after their grasping. Furthermore, the intraoral taste properties of amino acids remain the same as in the intact fish.     

<Emphasis Type="Italic">In vitro</Emphasis> regeneration of Persian poppy (<Emphasis Type="Italic">Papaver bracteatum</Emphasis>)

Persian poppy (Papaver bracteatum Lindl.) is an important commercial source of medicinal opiates and related compounds. In this research, calli were induced from seeds, roots, cotyledons and hypocotyls of P. bracteatum at a high efficiency. The optimized callus induction media consisted of the Murashige and Skoog (MS) basic media supplemented with 1.0 mg/L 2, 4-dichlorophenoxyacetic acid (2,4-D), 0.1 mg/L kinetin and 15 mg/L ascorbic acid. The concentrations of 2,4-D and ascorbic acid were found critical to callus induction and proliferation. Subsequent subcultures resulted in excellent callus proliferation. Ascorbic acid at concentration 15 mg/L increased the callus proliferation significantly. Maximum callus growth was achieved when the explants were incubated at 25°C. MS salts at full strength were found inhibitory for callus induction, while ľ MS salts were found to favor callus induction. Shoot regeneration of calli in vitro was achieved on ľ MS medium containing 0.5 mg/L benzylamine purine and 1.0 mg/L naphthalene acetic acid. Analysis of alkaloid extracts from Persian poppy tissues by high-performance liquid chromatography showed that thebaine accumulated in the tissues of plants. The thebaine alkaloid profile of the Persian poppy is a well-defined model to evaluate the potential for metabolic engineering of thebaine production in P. bracteatum.     

Intraspecific genetic polymorphism of Russian sturgeon <Emphasis Type="Italic">Acipenser gueldenstaedtii</Emphasis>

Three populations (Azov, Caspian, and Black Sea) of Russian sturgeon Acipenser queldenstaedtii were tested for polymorphism at nuclear (RAPD and microsatellites) and mitochondrial (PCR identification of two mitotypes) markers. In addition, morphometric analysis of he representatives of Azov population was carried out. According to the morphological characters, the Black Sea population occupied an intermediate position between the Caspian and Azov populations, reflecting the phylogeography of this species. In agreement with the morphometric data, genetic distances (the data of STR analysis) also placed the Black Sea population between the Caspian and Azov populations (F _ST = 0.058 and 0.043). The genetic distance between the Azov and Caspian population was somewhat higher (F _ST = 0.070). The highest allelic polymorphism at four microsatellite loci was found observed in Caspian population, while the lowest polymorphism was in the Sea of Azov. RAPD analysis distinguished high polymorphism within the populations, although it was not feasible for interpopulation analysis. Using the method differentiating the “baerii-like” and typical “gueldenstaedtii” mitotypes, the absence of the “baerii-like” marker in the Black Sea population was demonstrated. The frequency of this marker in Caspian and Azov populations constituted 31.1 and 1.8%, respectively. Possible evolutionary reasons for the interpopulation differences observed are discussed.     

Siberian sturgeon <Emphasis Type="Italic">Acipenser baerii</Emphasis> in the River Pechora

The paper reports the first reliable capture since the last 150 yr of two sturgeons in the basin of the River Pechora. Both specimens had the systematic traits of the Siberian sturgeon Acipenser baerii but differed significantly in external morphology. Data on biological traits and morphological parameters of the fish are presented. It is suggested that Pechora Basin should be included into the range of the Siberian sturgeon. Occurrences of the Siberian sturgeon in Pechora are discussed.     

<Emphasis Type="Italic">Galleria</Emphasis><Emphasis Type="Italic">mellonella</Emphasis> are Resistant to <Emphasis Type="Italic">Pneumocystis</Emphasis><Emphasis Type="Italic">murina</Emphasis> Infection

Studying Pneumocystis has proven to be a challenge from the perspective of propagating a significant amount of the pathogen in a facile manner. The study of several fungal pathogens has been aided by the use of invertebrate model hosts. Our efforts to infect the invertebrate larvae Galleria mellonella with Pneumocystis proved futile since P. murina neither caused disease nor was able to proliferate within G. mellonella. It did, however, show that the pathogen could be rapidly cleared from the host.     

<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.     

New combinations and typifications in <Emphasis Type="Italic">Bistorta</Emphasis>, <Emphasis Type="Italic">Persicaria</Emphasis>, <Emphasis Type="Italic">Polygonum,</Emphasis> and <Emphasis Type="Italic">Rumex</Emphasis> (Polygonaceae)

New combinations are proposed in anticipation of the Polygonaceae treatment in the forthcoming volume of Intermountain Flora: Polygonum kelloggii var. esotericum, P. kelloggii var. watsonii , Rumex densiflorus var. pycnanthus , R. salicifolius var. utahensis, and R. occidentalis var. tomentellus. Typifications are proposed to facilitate ongoing studies in Polygonaceae and to maintain current usage.     

<Emphasis Type="Italic">Quinua</Emphasis> and Relatives (<Emphasis Type="Italic">Chenopodium</Emphasis> sect.<Emphasis Type="Italic">Chenopodium</Emphasis> subsect.<Emphasis Type="Italic">Celluloid</Emphasis>)

Traditionally viewed as an Andean grain crop,Chenopodium quinoa Willd. includes domesticated populations that are not Andean, and Andean populations that are not domesticated. Comparative analysis of leaf morphology and allozyme frequencies have demonstrated that Andean populations, both domesticated(quinua) and free-living(ajara), represent an exceptionally homogeneous unit that is well differentiated from allied domesticates of coastal Chile(quingua) and freeliving populations of the Argentine lowlands(C. hircinum). This pattern of relationships indicates that Andean populations represent a monophyletic crop/weed system that has possibly developed through cyclic differentiation (natural vs. human selection) and introgressive hybridization. Relative levels of variation suggest that this complex originated in the southern Andes, possibly from wild types allied withC. hircinum, with subsequent dispersal north to Colombia and south to the Chilean coast. Coastal populations were apparently isolated from post-dispersal differentiation and homogenization that occurred in the Andes. Other data point toward a center of origin in the northern Andes with secondary centers of genetic diversity subsequently developing in the southern Andes and the plains of Argentina. Comparative linkage of South American taxa, all tetraploid, with North American tetraploids of the subsection will eventually clarify this problem. While the possibility of a direct phyletic connection betweenC. quinoa and the Mexican domesticate(C. berlandieri subsp. nuttalliae,) cannot be excluded, available evidence indicates that the latter represents an autonomous lineage that is associated with the basal tetraploid, C. b. subsp.berlandieri, through var.sinuatum, whereas South American taxa show possible affinities to either var. zschackei or var.berlandieri. An extinct domesticate of eastern North America,C. b. subsp.jonesianum, represents either another instance of independent domestication, possibly from subsp. b. var.zschackei, or a northeastern outlier of subsp.nuttalliae.     

Floral development and systematic position of <Emphasis Type="Italic">Arillastrum</Emphasis>, <Emphasis Type="Italic">Allosyncarpia</Emphasis>, <Emphasis Type="Italic">Stockwellia</Emphasis> and <Emphasis Type="Italic">Eucalyptopsis</Emphasis> (Myrtaceae)

We have investigated the floral ontogeny of Arillastrum, Allosyncarpia, Stockwellia and Eucalyptopsis (of the eucalypt group, Myrtaceae) using scanning electron microscopy and light microscopy. Several critical characters for establishing relationships between these genera and to the eucalypts have been determined. The absence of compound petaline primordia in Arillastrum, Allosyncarpia, Stockwellia and Eucalyptopsis excludes these taxa from the eucalypt clade. Post-anthesis circumscissile abscission of the hypanthium above the ovary in Stockwellia, Eucalyptopsis and Allosyncarpia is evidence that these three taxa form a monophyletic group; undifferentiated perianth parts and elongated fusiform buds are characters that unite Stockwellia and Eucalyptopsis as sister taxa. No floral characters clearly associate Arillastrum with either the eucalypt clade or the clade of Stockwellia, Eucalyptopsis and Allosyncarpia.We gratefully acknowledge Clyde Dunlop and Bob Harwood (Northern Territory Herbarium) for collecting specimens of Allosyncarpia, and Bruce Gray (Atherton) for collecting specimens of Stockwellia. The Australian National Herbarium (CANB) kindly lent herbarium specimens of Eucalyptopsis for examination. This research was supported by a University of Melbourne Research Development Grant to Andrew Drinnan.     

Pedogamy in <Emphasis Type="Italic">Neidium</Emphasis> (<Emphasis Type="Italic">Bacillariophyceae</Emphasis>)

Single (unpaired) vegetative cells of freshwater pennate diatom Neidium cf. ampliatum differentiated into gametangia and produced a single zygote (auxospore) via a pedogamic process. The gametic nuclei fused after auxospore expansion had begun. The auxospore expanded in parallel to the apical axis of the gametangium.     

Revision of the <Emphasis Type="Italic">Serrulati</Emphasis> species of <Emphasis Type="Italic">Penstemon</Emphasis> section <Emphasis Type="Italic">Saccanthera</Emphasis> subsection <Emphasis Type="Italic">Serrulati</Emphasis>

A revision of Penstemon sect. Saccanthera subsect. Serrulati includes a new species (P. salmonensis), a new variety (P. triphyllus var. infernalis), and the elevation of a subspecies to species (P. curtiflorus), bringing the total number of species to eight, which are keyed and described, complete with nomenclature and type citations.     

<Emphasis Type="Italic">Agrobacterium</Emphasis><Emphasis Type="Italic">tumefaciens</Emphasis>-mediated transformation of callus cells of <Emphasis Type="Italic">Crataegus</Emphasis><Emphasis Type="Italic">aronia</Emphasis>

A genetic transformation system has been developed for callus cells of Crataegus aronia using Agrobacterium tumefaciens. Callus culture was established from internodal stem segments incubated on Murashige and Skoog (MS) medium supplemented with 5 mg l⁻¹ Indole-3-butyric acid (IBA) and 0.5 mg l⁻¹ 6-benzyladenine (BA). In order to optimize the callus culture system with respect to callus growth and coloration, different types and concentrations of plant growth regulators were tested. Results indicated that the best average fresh weight of red colored callus was obtained on MS medium supplemented with 2 mg l⁻¹ 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l⁻¹ kinetin (Kin) (callus maintenance medium). Callus cells were co-cultivated with Agrobacterium harboring the binary plasmid pCAMBIA1302 carrying the mgfp5 and hygromycin phosphotransferase (hptII) genes conferring green fluorescent protein (GFP) activity and hygromycin resistance, respectively. Putative transgenic calli were obtained 4 weeks after incubation of the co-cultivated explants onto maintenance medium supplemented with 50 mg l⁻¹ hygromycin. Molecular analysis confirmed the integration of the transgenes in transformed callus. To our knowledge, this is the first time to report an Agrobacterium-mediated transformation system in Crataegus aronia.     

<Emphasis Type="Italic">P</Emphasis>rediction-<Emphasis Type="Italic">O</Emphasis>riented <Emphasis Type="Italic">M</Emphasis>arker <Emphasis Type="Italic">S</Emphasis>election (PROMISE): With Application to High-Dimensional Regression

In personalized medicine, biomarkers are used to select therapies with the highest likelihood of success based on an individual patient’s biomarker/genomic profile. Two goals are to choose important biomarkers that accurately predict treatment outcomes and to cull unimportant biomarkers to reduce the cost of biological and clinical verifications. These goals are challenging due to the high dimensionality of genomic data. Variable selection methods based on penalized regression (e.g., the lasso and elastic net) have yielded promising results. However, selecting the right amount of penalization is critical to simultaneously achieving these two goals. Standard approaches based on cross-validation (CV) typically provide high prediction accuracy with high true positive rates (TPRs) but at the cost of too many false positives. Alternatively, stability selection (SS) controls the number of false positives, but at the cost of yielding too few true positives. To circumvent these issues, we propose prediction-oriented marker selection (PROMISE), which combines SS with CV to conflate the advantages of both methods. Our application of PROMISE with the lasso and elastic net in data analysis shows that, compared to CV, PROMISE produces sparse solutions, few false positives, and small type I + type II error, and maintains good prediction accuracy, with a marginal decrease in the TPRs. Compared to SS, PROMISE offers better prediction accuracy and TPRs. In summary, PROMISE can be applied in many fields to select regularization parameters when the goals are to minimize false positives and maximize prediction accuracy.     

<Emphasis Type="Italic">In silico</Emphasis> and <Emphasis Type="Italic">in situ</Emphasis> characterization of the zebrafish (<Emphasis Type="Italic">Danio rerio</Emphasis>) <Emphasis Type="Italic">gnrh3</Emphasis> (sGnRH) gene

Background

Gonadotropin releasing hormone (GnRH) is responsible for stimulation of gonadotropic hormone (GtH) in the hypothalamus-pituitary-gonadal axis (HPG). The regulatory mechanisms responsible for brain specificity make the promoter attractive for in silico analysis and reporter gene studies in zebrafish (Danio rerio).

Results

We have characterized a zebrafish [Trp⁷, Leu⁸] or salmon (s) GnRH variant, gnrh 3. The gene includes a 1.6 Kb upstream regulatory region and displays the conserved structure of 4 exons and 3 introns, as seen in other species. An in silico defined enhancer at -976 in the zebrafish promoter, containing adjacent binding sites for Oct-1, CREB and Sp1, was predicted in 2 mammalian and 5 teleost GnRH promoters. Reporter gene studies confirmed the importance of this enhancer for cell specific expression in zebrafish. Interestingly the promoter of human GnRH-I, known as mammalian GnRH (mGnRH), was shown capable of driving cell specific reporter gene expression in transgenic zebrafish.

Conclusions

The characterized zebrafish Gnrh3 decapeptide exhibits complete homology to the Atlantic salmon (Salmo salar) GnRH-III variant. In silico analysis of mammalian and teleost GnRH promoters revealed a conserved enhancer possessing binding sites for Oct-1, CREB and Sp1. Transgenic and transient reporter gene expression in zebrafish larvae, confirmed the importance of the in silico defined zebrafish enhancer at -976. The capability of the human GnRH-I promoter of directing cell specific reporter gene expression in zebrafish supports orthology between GnRH-I and GnRH-III.

     

Osmo- and ionoregulatory responses of green sturgeon (<Emphasis Type="Italic">Acipenser medirostris</Emphasis>) to salinity acclimation

The green sturgeon is a long-lived, highly migratory species with populations that are currently listed as threatened. Their anadromous life history requires that they make osmo- and ionoregulatory adjustments in order to maintain a consistent internal milieu as they move between fresh-, brackish-, and seawater. We acclimated juvenile green sturgeon (121 ± 10.0 g) to 0 (freshwater; FW), 15 (estuarine; EST), and 24 g/l (SF Bay water; BAY) at 18°C for 2 weeks and measured the physiological and biochemical responses with respect to osmo- and ionoregulatory mechanisms. Plasma osmolality in EST- and BAY-acclimated sturgeon was elevated relative to FW-acclimated sturgeon (P < 0.01), but there was no difference in muscle water content or abundance of stress proteins. Branchial Na⁺, K⁺-ATPase (NKA) activity was also unchanged, but abundance within mitochondrion-rich cells (MRC) was greater in BAY-acclimated sturgeon (P < 0.01). FW-acclimated sturgeon had the greatest NKA abundance when assessed at the level of the entire tissue (P < 0.01), but there were no differences in v-type H⁺ATPase (VHA) activity or abundance between salinities. The Na⁺, K⁺, 2Cl⁻ co-transporter (NKCC) was present in FW-acclimated sturgeon gills, but the overall abundance was lower relative to sturgeon in EST or BAY water (P < 0.01) where this enzyme is crucial to hypoosmoregulation. Branchial caspase 3/7 activity was significantly affected by acclimation salinity (P < 0.05) where the overall trend was for activity to increase with salinity as has been commonly observed in teleosts. Sturgeon of this age/size class were able to survive and acclimate following a salinity transfer with minimal signs of osmotic stress. The presence of the NKCC in FW-acclimated sturgeon may indicate the development of SW-readiness at this age/size.     

Isolation and characterization of the <Emphasis Type="Italic">Larix gmelinii </Emphasis><Emphasis Type="Italic">ANGUSTIFOLIA</Emphasis> (<Emphasis Type="Italic">LgAN</Emphasis>) gene

ANGUSTIFOLIA (AN), a plant homolog of C-terminal binding protein, controls the polar elongation of leaf cells and the trichome-branching pattern in Arabidopsis thaliana. In the present study, degenerate PCR was used to isolate an ortholog of AN, referred to as LgAN, from larch (Larix gmelinii). The LgAN cDNA is predicted to encode a protein of 646 amino acids that shows striking sequence similarity to AN proteins from other plants. The predicted amino acid sequence has a conserved NAD-dependent 2-hydroxy acid dehydrogenase (D2-HDH) motif and a plant AN-specific LxCxE/D motif at its N-terminus, as well as a plant-specific long C-terminal region. The LgAN gene is a single-copy gene that is expressed in all larch tissues. Expression of the LgAN cDNA rescued the leaf width and trichome-branching pattern defects in the angustifolia-1 (an-1) mutant of Arabidopsis, showing that the LgAN gene has effects complementary to those of AN. These results suggest that the LgAN gene has the same function as the AN gene.