A pheromone bouquet controls the reproductive behaviour of the male shore crab,Carcinus maenas

Aquatic Ecology - The reproduction of many brachyuran crustaceans involves the formation of mating pairs often around the time of the female moult with attraction of a sexual partner and mating...     

UV-Repair is impaired in fibroblasts from patients with Fanconi's anemia

Summary Fanconi's anemia, a hereditary autosomal disease with chromosomal instability, elevated incidence of cancer and clinical symptoms is accompanied by a DNA repair deficiency. Fibroblasts from patients with Fanconi's anemia were found to be impaired in the DNA repair of UV damage. Nucleoid decondensation and recondensation after UV irradiation were less efficient in fibroblasts from patients with Fanconi's anemia than in those from a healthy proband. These data confirm our earlier findings that DNA ligase is deficient in Fanconi's anemia.     

The plant growth retardant CCC as inhibitor of gibberellin biosynthesis inFusarium moniliforme

Summary Gibberellin (GA) production inFusarium moniliforme (Gibberella fujikuroi) is suppresed by adding the plant growth retardant CCC [(2-chloroethyl)trimethylammonium chloride] to the culture medium. A concentration of 0.1 mg/l of CCC causes 50% inhibition whereas 10 mg/l and higher concentrations fully suppress GA production. Dry weight of the mycelium is not, or only slightly reduced in the presence of CCC.Thin-layer chromatography of acidic fractions of CCC-free cultures reveals fluorescent spots at 4 differentR _f values. No fluorescent spots can be detected on chromatograms of acidic fractions obtained from CCC cultures, thus demonstrating that production of all GA's is inhibited by CCC.If CCC is added to the medium 2 or 3 days after inoculation, further GA production is blocked, but the level of GA present at the time of CCC application is maintained. CCC does not enhance inactivation of GA₃ in sterile culture medium, nor in the presence of the fungus. It is therefore concluded that CCC inhibits the biosynthesis of GA in the fungus.Transfer of thoroughly washed mycelium from medium with CCC to fresh medium does not result in GA production because sufficient CCC is carried over in the mycelium to block GA biosynthesis completely.     

Enhancing tellurite and selenite bioconversions by overexpressing a methyltransferase from Aromatoleum sp. CIB

Pollution by metalloids, e.g., tellurite and selenite, is of serious environmental concern and, therefore, there is an increasing interest in searching for ecologically friendly solutions for their elimination. Some microorganisms are able to reduce toxic tellurite/selenite into less toxic elemental tellurium (Te) and selenium (Se). Here, we describe the use of the environmentally relevant β-proteobacterium Aromatoleum sp. CIB as a platform for tellurite elimination. Aromatoleum sp. CIB was shown to tolerate 0.2 and 0.5 mM tellurite at aerobic and anaerobic conditions, respectively. Furthermore, the CIB strain was able to reduce tellurite into elemental Te producing rod-shaped Te nanoparticles (TeNPs) of around 200 nm length. A search in the genome of Aromatoleum sp. CIB revealed the presence of a gene, AzCIB_0135, which encodes a new methyltransferase that methylates tellurite and also selenite. AzCIB_0135 orthologs are widely distributed in bacterial genomes. The overexpression of the AzCIB_0135 gene both in Escherichia coli and Aromatoleum sp. CIB speeds up tellurite and selenite removal, and it enhances the production of rod-shaped TeNPs and spherical Se nanoparticles (SeNPs), respectively. Thus, the overexpression of a methylase becomes a new genetic strategy to optimize bacterial catalysts for tellurite/selenite bioremediation and for the programmed biosynthesis of metallic nanoparticles of biotechnological interest.