Application of DNA parentage analyses for determining relative growth rates of Penaeus japonicus families reared in commercial ponds

The ability to track large numbers of individuals and families is a key determinant of the power and precision of breeding programs, including the capacity to quantify interactions between genotypes and their environment. Until recently, most family based selective breeding programs for shrimp, and other highly fecund aquaculture species, have been restricted by the number of animals that can be physically tagged and individually selected. Advances in the development of molecular markers, such as microsatellite loci, are now providing the means to track large numbers of individuals and families in commercial production systems. In this study microsatellites, coupled with DNA parentage analyses, were used to determine the relative performance of 22 families of R japonicus reared in commercial production ponds. In the experimental design 6000 post-larvae from each of 22 families, whose maternal parents had been genotyped at 8 microsatellite loci, were stocked into each of four I ha ponds. After 6 months the ponds were harvested and a total of 6000 individuals were randomly weighed from each pond. Mean wet weight of the shrimp from one pond was significantly lower than that of the other three ponds demonstrating a possible pond effect on growth rate. The representation of families in the top 10% of each pond's weight distribution was then determined by randomly genotyping up to 300 individuals from this upper weight class. Parentage analyses based on individual genotypic data demonstrated that some families were over-represented in the top 10% in all ponds, while others were under-represented due to slower growth rates. The results also revealed some weak, but significant, male genotype x environment (G x E) interactions in the expression of shrimp growth for some families. This indicates that G x E effects may need to be factored into future R japonicus selective breeding programs. This study demonstrated the utility of DNA parentage analyses for tracking individual family performance in communally stocked shrimp pond populations and, its application to examining G x E effects on trait expression under commercial culture conditions. Crown Copyright (c) 2005 Published by Elsevier B.V. All rights reserved.

Pattern analysis on protein properties of Chinese and CIMMYT spring wheat cultivars sown in China and CIMMYT

Improvement of processing quality is a very important objective for Chinese wheat breeding programs. Twenty-five CIMMYT and Chinese spring wheat cultivars were grown at four managed conditions by CIMMYT in Cd. Obregon, Sonora, Mexico and in nine environments in China, over two successive wheat seasons from 2000 to 2002. These trials were used to identify patterns of cultivar, environment and cultivar x environment interactions, and to determine opportunities for indirect selection for protein content and the protein-quality related parameter, SDS sedimentation (SDSS) value. The cultivar Inqalab 91 showed low levels of interaction with environments in the 2000-01 crop cycle for protein content, and expressed intermediate levels for both protein content and SDSS value, across most of the environments in both years. Longmai 26 had consistently high protein content and SDSS value across environments in both years, indicating that it is possible to breed cultivars expressing high yields with good protein properties. Cluster analyses revealed that cultivars grouped differently for protein content and SDSS value. Besides photoperiod, water availability appeared to influence the ranking of cultivars for protein content and SDSS value. Temperature and soil type may underlie the observed interactions for protein content, while temperature may also be a factor associated with interactions for SDSS value. The full irrigation managed environment in Mexico, with the cultivars sown on raised beds two months later than optimum and exposing them to late heat, clustered together with the Chinese environments Huhhot, Yongning, and Hejin in the 2000-01 season for SDSS value. This indicates that there is an opportunity to exploit indirect responses to selection in the CIMMYT management environments for SDSS value with relevance for China's spring wheat regions. However, there seemed little chance for positive indirect selection in CIMMYT's managed environments for China in regard to protein content, as environments clustered distinctly. Pattern analyses permitted a sensible and useful summary for this multi environment experiment, helping in understanding natural relationships and variations in cultivar performance among the various environment groups, and assisting in the structuring of environments.

Neurobiological alterations in the human alcoholic brain: effect of genotype

Long-term alcohol abuse by human subjects leads to selective brain damage that is restricted in extent and variable in severity. Within the cerebral cortex, neuronal loss is most marked in the superior frontal cortex and relatively mild in motor cortex. Cirrhotic alcoholics and subjects with alcohol-related Wernicke-Korsakoff syndrome show more severe and more extensive damage than do uncomplicated cases. Accumulating evidence suggests that the likelihood of developing alcohol dependency is associated with one or more genetic markers. In previous work we showed that GABAA receptor functionality, and the subunit isoform expression that underlies this, differed in region- and disease-specific ways between alcoholics and controls. By contrast, glutamate receptor (NMDA, KA, AMPA) differences were muted or absent. Here we asked if genotype differentiated the form, pharmacology, or expression of glutamate and GABA receptors in pathologically vulnerable and spared cortical regions, with a view to determining whether such subject factors might influence the severity of alcohol-induced brain damage. Cerebrocortical tissue was obtained at autopsy under informed, written consent from uncomplicated and alcoholic-cirrhotic Caucasian (predominantly Anglo-Celtic) cases, together with matched controls and cases with cirrhosis of non-alcoholic origin. All subjects had pathological confirmation of liver and brain diagnosis; none had been polydrug abusers. Samples were processed for synaptic membrane receptor binding, mRNA analysis by quantitative RT-PCR, and protein analysis by Western blot. Genotyping was performed by PCR methods, in the main using published primers. Several genetic markers differentiated between our alcoholic and control subjects, including the GABAA receptor 2 subunit (GABB2) gene ( 2 (3) 10.329, P 0.01), the dopamine D2 receptor B1 (DRD2B) allele ( 2 (3) 10.109, P 0.01) and a subset of the alcohol dehydrogenase-3 (ADH3) alleles ( 2 (2) 4.730, P 0.05). Although neither the type-2 glutamate transporter (EAAT2) nor the serotonin transporter (5HTT) genes were significantly associated with alcoholism, only EAAT2 heterozygotes showed a significant association between ADH3 genotype and alcoholism ( 2 (3) 7.475, P 0.05). Other interactions between genotypes were also observed. DRD2A, DRD2B, GABB2, EAAT2 and 5HTT genotypes did not divide alcoholic cases and controls on NMDA receptor parameters, although in combined subjects there was a significant DRD2B X Area Interaction with glutamateNMDA receptor efficacy (F(1,57) 4.67; P 0.05), measured as the extent of glutamate-enhanced MK801 binding. In contrast, there was a significant Case-group X ADH3 X Area Interaction with glutamateNMDA receptor efficacy (F(3,57) 2.97; P 0.05). When GABAA receptor subunit isoform expression was examined, significant Case-group X Genotype X Area X Isoform interactions were found for EAAT2 with subunit mRNA (F(1,37) 4.22; P0.05), for GABB2 with isoform protein (F(1,37) 5.69; P 0.05), and for DRD2B with isoform protein (F(2,34)5.69; P0.05). The results suggest that subjects’ genetic makeup may modulate the effectiveness of amino acid-mediated transmission in different cortical regions, and thereby influence neuronal vulnerability to excitotoxicity.

Interactions between serotonergic genotype and amino acid transmitter receptor expression in human alcoholics

Serotonin can modulate the activity of neural reward pathways that are strongly implicated in mediating the effects of chronic alcohol misuse, and its treatment, in human subjects. In previous work and as discussed elsewhere at this meeting, we and others have found consistent differences in the parameters of GABA and glutamate receptors, and the expression of their component subunit transcripts and proteins, in areas of the alcoholic brain that are altered by alcoholism. We did not fi nd clear changes in GABA and glutamate transport function in such samples, but a series of microarray analyses showed consistent upregulation of the presynaptic GABA/betaine transporter SLC6A12. Microarray studies showed no signifi cant differences in the expression of transcripts associated with 5HT transmission; however, only a small number of such elements were present on the arrays. Here we partitioned GABAA and NMDA pharmacology, and subunit mRNA and protein expression, measured in samples of frontal and motor cortex obtained at autopsy from alcoholics without comorbid disease, alcoholics with liver cirrhosis, and controls, according to 5HTTLPR (SLC6A4) and 5HT1B (HTR1B) polymorphisms. We found no effect of these genotypes on the expression of GABAA receptor gene products, but there was a signifi cant mRNA Transcript X Area X Group X 5HTTLPR Interaction with NMDA subunit isoform expression measured by Real Time PCR with GAPDH normalization. Further analysis showed the effect to be selective for alcoholics with cirrhosis, to be most marked in the pathologically vulnerable frontal cortex, and to vary with subunit transcript (F2,76 = 6.545, P = 0.002). NR1 expression was most affected, followed by NR2A, with NR2B expression least altered. Pilot data suggest 5HT1B genotype may also modulate NMDA subunit expression. Interactions between amino acid and serotonin transmission may infl uence susceptibility to alcohol dependence or pathogenesis

Optimization of Rational Approximations by Continued Fractions

The paper has been presented at the 12th International Conference on Applications of Computer Algebra, Varna, Bulgaria, June, 2006.

Oscillation Theorems for Second Order Sublinear Ordinary Differential Equations

Oscillation criteria are given for the second order sublinear non-autonomous differential equation. (r(t) (x)x′(t))′ + q(t)g(x(t)) = (t). These criteria extends and improves earlier oscillation criteria of Kamenev, Kura, Philos and Wong. Oscillation criteria are also given for second order sublinear damped non-autonomous differential equations.

Acceleration of Convergence in Dontchev’s Iterative Method for Solving Variational Inclusions

2000 Mathematics Subject Classification: 47H04, 65K10.

Automorphisms of the Planar Tree Power Series Algebra and the Non-Associative Logarithm

2000 Mathematics Subject Classification: 17A50, 05C05.

Minimal Codewords in Linear Codes

2000 Mathematics Subject Classification: 94B05, 94B15.

About Homogeneous Spaces and the Baire Property in Remainders

Александър В. Архангелски, Митрофан М. Чобан, Екатерина П. Михайлова - В съобщението е продължено изследването на понятията o-хомогенно пространство, lo-хомогенно пространство, do-хомогенно пространство и co-хомогенно пространство. Показано е, че ако co-хомогенното пространство X съдържа Gδ -гъсто Московско подпространство, тогава X е Московско пространство.

Oscillation Criteria for Nonlinear Differential Equations of Second Order with Damping Term

2000 Mathematics Subject Classification: 34C10, 34C15.

An Iterative Procedure for Solving Nonsmooth Generalized Equation

2000 Mathematics Subject Classification: 47H04, 65K10.

Lokális energiamódszer kicsi rendben gerjesztett Liénard-egyenletekre (Local energy method for little order forced equations)

Az x''+f(x) x'+g(x) = 0 alakú Liénard-típusú differenciálegyenlet központi szerepet játszik az üzleti ciklusok Káldor-Kalecki-féle [3,4] és Goodwin-féle [2] modelljeiben, sőt egy a munkanélküliség és vállalkozás-ösztönzések ciklikus változásait leíró újabb modellben [1] is. De ugyanez a nemlineáris egyenlettípus a gerjesztett ingák és elektromos rezgőkörök elméletét is felöleli [5]. Az ezzel kapcsolatos irodalom nagyrészt a határciklusok létezését vizsgálja (pl. [5]), pedig az alapvető stabilitási kérdések jóval áttekinthetőbb módon kezelhetők, s a kapott eredmények közvetve a határciklusok létezésének feltételeit is sokkal jobban be tudják határolni. Jelen dolgozatban az egyváltozós analízis hatékony nyelvezetével olyan egyszerűen megfogalmazható eredményekhez jutunk, amelyek képesek kitágítani az üzleti és más közgazdasági ciklusok modelljeinek kereteit, illetve pl. az [1]-beli modellhez újabb szemléltető speciális eseteket is nyerünk. ____ The Liénard type differential equation of the form x00 + f(x) ¢ x0 + g(x) = 0 has a central role in business cycle models by Káldor [3], Kalecki [4] and Goodwin [2], moreover in a new model describing the cyclical behavior of unemployment and entrepreneurship [1]. The same type of nonlinear equation explains the features of forced pendulums and electric circuits [5]. The related literature discusses mainly the existence of limit cycles, although the fundamental stability questions of this topic can be managed much more easily. The achieved results also outline the conditions for the existence of limit cycles. In this work, by the effective language of real valued analysis, we obtain easy-formulated results which may broaden the frames of economic and business cycle models, moreover we may gain new illustrative particular cases for e.g., [1].

The effects of fertilization and simulated grazing on the community structure of a seagrass bed in South Florida

The importance of resource supply and herbivory in driving competitive interactions among species has been an important but contentious issue within ecology. These variables exhibit different effects on species competition when manipulated in isolation but interact when manipulated together. I tested the direct and interactive effects of nutrient addition and simulated grazing (clipping) on the competitive performance of primary producers and community structure of a seagrass bed in South Florida. One square meter experimental plots were established in a mixed seagrass meadow from August 2007 to July 2009. The experiment was a 3 x 3 factorial experiment: 3 fertility treatments: control, medium (2.4 mg N d−1 and 80 µg P day −1) and high (4.8 mg N d−1 and 160 µg P day−1) x 3 clipping intensities (0, 25% and 50 % biomass removal (G)) x 5 replicates for each treatment = 45 plots). Nutrient additions and simulated grazing were done every two months. Fertilization and simulated grazing decreased sexual reproduction in S. filiforme. Fertilization increased competitive dominance within the primary producers while simulated grazing counteracted this effect by removal of the dominant species. Fertilization ameliorated the negative impacts of simulated grazing while simulated grazing prevented competitive exclusion in the fertilized plots. Nutrient addition and simulated grazing both exerted strong control on plant performance and community structure. Neither bottom up nor top down influences was eliminated in treatments where both factors where present. The effects of fertilization on plant performance were marked under all clipping intensities indicating that the system is regulated by nutrient availability both in the presence or absence of grazers. Clipping effects were strong under both fertilized and unfertilized conditions indicating that the seagrass bed can be simultaneously under top-down control by grazers.

Odour flux from litter of broiler chickens fed diets differing in protein levels and additives

The effect of dietary crude protein (CP) and additives on odour flux from broiler litter was investigated using 180 day-old Ross 308 male chicks randomly allocated to five dietary treatments with three replications of 12 birds each. A 5×3 factorial arrangement of treatments was employed. Factors were: diet (low CP, high CP, high CP+antibiotic, high CP+probiotic, high CP+saponin) and age (15, 29, 35 days). Low CP (LCP) and high CP (HCP) diets differed in CP levels by 4.5-5%. The low CP diets were supplemented with L-valine, L-isoleucine, L-arginine, L-lysine, D,L-methionine and L-threonine. The antibiotic used was Zn Bacitracin, the probiotic was a blend of three Bacillus subtilis strains and the saponin came from a blend of Yucca and Quillaja. Odorants were measured from litter headspace using a flux hood and selective ion flow tube mass spectrometry (SIFT-MS). Results were log tranformed and analysed by two-way ANOVA with repeated measures using JMP statistical software v.8, and means were separated by Tukey's HSD test at P<0.05.The results showed that LCP group produced lower flux of dimethyl amine, trimethyl amine, H2S, NH3 and phenol in litter compared to HCP group (P<0.05). Similarly, HCP+probiotic group produced lower flux of H2S (P<0.05) and HCP+saponin group produced lower flux of trimethylamine and phenol in litter compared to HCP group (P<0.05). The dietary treatments tended (P=0.065) to have higher flux of methanethiol in HCP group compared to others. There was a diet x age interaction for litter flux of diacetyl, acetoin, 3-methyl-1-butanol, 3-methylbutanal, ethanethiol, propionic acid and hexane (P<0.05). Concentrations of diacetyl, acetoin, propionic acid and hexane in litter were higher from LCP group compared to all other treatments on d 35 (P<0.05) but not on days 15 and 29. Thus, the low CP diet, Bacillus subtilis based probiotic and Yucca/Quillaja based saponin were effective in reducing the emissions of some key odorants from broiler litter.