Hypophysierung von Aquarienkarpfen und künstliche Laicherbrütung als Methode zur Züchtung neuer Karpfenrassen

Zusammenfassung Es wird über eine kombinierte Aufzucht- und Vermehrungsmethode von Karpfen berichtet, die zur schnelleren Realisierung neuer Züchtungen beiträgt.Im Aquarium aufgezogene Karpfen (Cyprinus carpio), die mit Trockenfutter ernährt worden waren, erreichten bereits nach zwei Jahren die Geschlechtsreife. Von diesen Tieren ließen sich nach Hypophyseninjektionen reifer Rogen und Milch gewinnen. Die Befruchtung und Erbrütung der Eier sowie die Anzucht der Jungfische erfolgte ebenfalls unter Laboratoriumsbedingungen. Es besteht kein endogener Sexualrhythmus bei Karpfen, denn die Laichgewinnung kann zu jeder Jahrezeit und bei denselben Eltern mehrmals im Jahr vollzogen werden. Die Methode der künstlichen Laichgewinnung und-erbrütung wird beschrieben. Das Verfahren eignet sich für züchterische und physiologische Arbeiten.

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Hypophyseal injections for aquarium carp and artificial spawning as a method for breeding new races of carp

Summary A method of raising and multiplying carp is reported which makes a faster establishment of new breeds possible.Carp (Cyprinus carpio) raised in aquaria and fed on dry food reached maturity already after two years. Pituitary injections make it possible to obtain roe and milt from such fish.Fertilization, hatching, and raising of the young are also performed under laboratory conditions.There is no endogenous sexual rhythm in carp, for spawning can be accomplished at any time of the year, and several times annually using the same parents. The method of artificially obtaining and hatching spawn is described. It is suitable for breeding and physiological experiments.A comparative analysis of the physiological dynamics in eggs, young fish, and adults is considerably simplified for the physiologist interested in metabolism, and the breeder can reach his goals more rapidly because of the shortened generation time.

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Herrn Prof. Dr.R. v. Sengbusch zum 70. Geburtstag gewidmet.     

Intraspecific chemical variability of the leaf essential oil of Juniperus phoenicea subsp. turbinata from Corsica

The composition of 50 samples of essential oil of individual plants of Juniperus phoenicea subsp. turbinata from Corsica was investigated by GC, GC-MS and 13C NMR. alpha-Pinene, beta-phellandrene, alpha-terpinyl acetate, Delta-3-carene, myrcene and alpha-phellandrene were found to be the main constituents. The results were submitted to cluster analysis and discriminant analysis which allowed two groups of essential oils to be distinguished with respect to the content of alpha-pinene, beta-phellandrene and alpha-terpinyl acetate.     

An assessment of false discovery rates and statistical significance in label-free quantitative proteomics with combined filters

Background  

Many studies have provided algorithms or methods to assess a statistical significance in quantitative proteomics when multiple replicates for a protein sample and a LC/MS analysis are available. But, confidence is still lacking in using datasets for a biological interpretation without protein sample replicates. Although a fold-change is a conventional threshold that can be used when there are no sample replicates, it does not provide an assessment of statistical significance such as a false discovery rate (FDR) which is an important indicator of the reliability to identify differentially expressed proteins. In this work, we investigate whether differentially expressed proteins can be detected with a statistical significance from a pair of unlabeled protein samples without replicates and with only duplicate LC/MS injections per sample. A FDR is used to gauge the statistical significance of the differentially expressed proteins.     

Sequence and structure of Brassica rapa chromosome A3

Background

The species Brassica rapa includes important vegetable and oil crops. It also serves as an excellent model system to study polyploidy-related genome evolution because of its paleohexaploid ancestry and its close evolutionary relationships with Arabidopsis thaliana and other Brassica species with larger genomes. Therefore, its genome sequence will be used to accelerate both basic research on genome evolution and applied research across the cultivated Brassica species.

Results

We have determined and analyzed the sequence of B. rapa chromosome A3. We obtained 31.9 Mb of sequences, organized into nine contigs, which incorporated 348 overlapping BAC clones. Annotation revealed 7,058 protein-coding genes, with an average gene density of 4.6 kb per gene. Analysis of chromosome collinearity with the A. thaliana genome identified conserved synteny blocks encompassing the whole of the B. rapa chromosome A3 and sections of four A. thaliana chromosomes. The frequency of tandem duplication of genes differed between the conserved genome segments in B. rapa and A. thaliana, indicating differential rates of occurrence/retention of such duplicate copies of genes. Analysis of 'ancestral karyotype' genome building blocks enabled the development of a hypothetical model for the derivation of the B. rapa chromosome A3.

Conclusions

We report the near-complete chromosome sequence from a dicotyledonous crop species. This provides an example of the complexity of genome evolution following polyploidy. The high degree of contiguity afforded by the clone-by-clone approach provides a benchmark for the performance of whole genome shotgun approaches presently being applied in B. rapa and other species with complex genomes.     

RTS, a rice anther-specific gene is required for male fertility and its promoter sequence directs tissue-specific gene expression in different plant species

A tapetum-specific gene, RTS, has been isolated by differential screening of a cDNA library from rice panicles. RTS is a unique gene in the rice genome. RNA blot analysis and in situ hybridization indicates that this gene is predominantly expressed in the anther’s tapetum during meiosis and disappears before anthesis. RTS has no introns and encodes a putative polypeptide of 94 amino acids with a hydrophobic N-terminal region. The nucleotide and deduced amino acid sequence of the gene do not show significant homology to any known sequences. However, a sequence in the promoter region, GAATTTGTTA, differs only by one or two nucleotides from one of the conserved motifs in the promoter region of two pollen-specific genes of tomato. Several other sequence motifs found in other anther-specific promoters were also identified in the promoter of the RTS gene. Transgenic and antisense RNA approaches revealed that RTS gene is required for male fertility in rice. The promoter region of RTS, when fused to the Bacillus amyloliquefaciens ribonuclease gene, barnase, or the antisense of the RTS gene, is able to drive tissue-specific expression of both genes in rice, creeping bentgrass (Agrostis stolonifera L.) and Arabidopsis, conferring male sterility to the transgenic plants. Light and near-infrared confocal microscopy of cross-sections through developing flowers of male-sterile transgenics shows that tissue-specific expression of barnase or the antisense RTS genes interrupts tapetal development, resulting in deformed non-viable pollen. These results demonstrate a critical role of the RTS gene in pollen development in rice and the versatile application of the RTS gene promoter in directing anther-specific gene expression in both monocotyledonous and dicotyledonous plants, pointing to a potential for exploiting this gene and its promoter for engineering male sterility for hybrid production of various plant species. Data deposition: The sequence reported in this paper have been deposited in the GeneBank database (Accession No. U12171)     

The co-distribution of Plasmodium falciparum and hookworm among African schoolchildren

Background

On the island of Bioko (Equatorial Guinea), insecticide-treated nets (ITNs) have been the main tool used to control malaria over the last 13 years. In 2004, started an indoor residual spraying (IRS) campaign to control malaria. The purpose of this study is to asses the impact of the two control strategies on the island of Bioko (Equatorial Guinea), with regards to Plasmodium infection and anaemia in the children under five years of age.

Methods

Two transversal studies, the first one prior to the start of the IRS campaign and the second one year later. Sampling was carried out by stratified clusters. Malaria infection was measured by means of thick and thin film, and the packed cell volume (PCV) percentage. Data related to ITN use and information regarding IRS were collected. The Pearson's chi-square and logistic regression statistical tests were used to calculate odds ratios (OR)

Results

In the first survey, 168 children were sampled and 433 children in the second one. The prevalence of infection was 40% in 2004, and significantly lower at 21.7% in 2005. PCV was 41% and 39%, respectively. 58% of the children surveyed in 2004 and 44.3% in 2005 had slept under an ITN. 78% of the dwellings studied in 2005 had been sprayed. In the 2005 survey, sleeping without a mosquito net meant a risk of infection 3 times greater than sleeping protected with a net hanged correctly and with no holes (p < 0.05).

Conclusion

IRS and ITNs have proven to be effective control strategies on the island of Bioko. The choice of one or other strategy is, above all, a question of operational feasibility and availability of local resources.     

Selenate reduction and adsorption in littoral sediments from a hypersaline California lake, the Salton Sea

The Salton Sea, a hypersaline lake located in Southern California, is a major habitat for migratory waterfowl, including endangered species, recently threatened by selenium toxicity. Selenium is both an essential micronutrient and a contaminant and its speciation and cycling are driven by microbial activity. In the absence of oxygen, microorganisms can couple the oxidation of organic matter with the reduction of soluble selenate and selenite to elemental selenium. In order to better understand and quantify selenium cycling and selenium transfer between water and underlying sediments in the Salton Sea, we measured the maximum potential selenate reduction rates (R _max) and selenate adsorption isotherms in sediments collected from seven littoral locations in July 2011. We also measured salinity, organic carbon, nitrogen, and elemental selenium content and the abundance of selenate-reducing prokaryotes at each site. Our results showed a high potential for selenate reduction and limited selenate adsorption in all studied sites. Maximum potential selenate reduction rates were affected by sediment C_org content. We showed that selenate reduction potential of Salton Sea sediments far outweighs current dissolved inputs to the lake. Selenate reduction is thus a likely driver for selenium removal from the lake’s water and selenate retention in littoral sediments of the Salton Sea.     

Methyl jasmonate deficiency alters cellular metabolome, including the aminome of tomato (Solanum lycopersicum L.) fruit

Exogenous treatment with jasmonates (JA) has been shown to reduce the levels of polyamines in many plants. But the role of endogenous JA on polyamine biosynthesis or other cellular metabolites has thus far remained uninvestigated. We developed transgenic tomato (Solanum lycopersicum L.) having severely reduced methyl JA levels by silencing a fruit ripening-associated lipoxygenase (LOX), SlLoxB, using a truncated LOX gene under the control of the constitutive CaMV35S promoter. The LOX suppressed and MeJA-deficient fruits had lowered polyamine levels. Thus, these transgenic fruits were used as a plant model to evaluate the effects of reduced endogenous MeJA on cellular metabolites in ripening tomato fruits using NMR spectroscopy. During on-shelf ripening, transgenic fruits were significantly reduced in the content of 19 out of 30 metabolites examined, including Ile, Val, Ala, Thr, Asn Tyr, Glu, Gln, His, Phe, Trp, GABA, citrate, succinate, myo-inositol, unidentified compound B, nucleic acid compound Nucl1, choline, and trigonelline as compared to the wild-type azygous counterparts. A significant increase in β-glucose levels in transgenic fruits was observed at the pink stage. The transgenic fruits were equivalent to the wild type in lycopene level and chlorophyll degradation rates. Taken together, these results show that intracellular MeJA significantly regulates overall primary metabolism, especially aminome (amino acids and polyamines) of ripening fruits.     

Streamlining genomes: toward the generation of simplified and stabilized microbial systems

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Highlights? Top-down and bottom-up approaches to genome streamlining. ? Computational support for constructing and refactoring streamlined genomes. ? From genome engineering to metabolic reprogramming. ? Perspectives in applied genome engineering.     

Habituation and the reinforcing effectiveness of visual stimuli

The term "sensory reinforcer" has been used to refer to sensory stimuli (e.g. light onset) that are primary reinforcers in order to differentiate them from other more biologically important primary reinforcers (e.g. food and water). Acquisition of snout poke responding for a visual stimulus (5s light onset) with fixed ratio 1 (FR 1), variable-interval 1min (VI 1min), or variable-interval 6min (VI 6min) schedules of reinforcement was tested in three groups of rats (n=8/group). The VI 6min schedule of reinforcement produced a higher response rate than the FR 1 or VI 1min schedules of visual stimulus reinforcement. One explanation for greater responding on the VI 6min schedule relative to the FR 1 and VI 1min schedules is that the reinforcing effectiveness of light onset habituated more rapidly in the FR 1 and VI 1min groups as compared to the VI 6min group. The inverse relationship between response rate and the rate of visual stimulus reinforcement is opposite to results from studies with biologically important reinforcers which indicate a positive relationship between response and reinforcement rate. Rapid habituation of reinforcing effectiveness may be a fundamental characteristic of sensory reinforcers that differentiates them from biologically important reinforcers, which are required to maintain homeostatic balance.