Isotope tracing in adult zebrafish reveals alanine cycling between melanoma and liver

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Microsatellite and morphological analysis of population structure in the parthenogenetic freshwater snail Melanoides tuberculata: insights into the creation of clonal variability

The distribution of variability was studied at various geographical scales in the tropical freshwater snail Melanoides tuberculata, in order to analyse the role of factors shaping this distribution, including the mating system and population dynamics. This parthenogenetic polyploid species reproduces mainly asexually, with males occurring at low frequency. About 800 individuals (38 sites) were sampled from Africa and the Middle East, where the species originated, and from recently colonized habitats in South and Central America, and especially the island of Martinique. We first described variation of general aspects and ornamentation of the shells. This analysis confirms the existence of discrete morphs. Second, individuals were studied at three microsatellite loci, showing that each morph is a genetic clone with some minor variation compatible with models of microsatellite evolution. The genetic analysis also showed much more variation within than between clones. However, two populations from Africa exhibited a large amount of variability, and a mixture of sexual and asexual reproduction might explain these genetic patterns. The worldwide distribution of variability is, therefore, compatible with the African origin of the species, and the introduction of a few clones in other parts of the world. These results also suggest that the distribution of variability in Martinique is influenced by flooding events, and that two morphs from Martinique can be interpreted as hybrids between two pre-existing morphs, based on morphological, genetic and geographical arguments.     

Studies of visible oscillating chemiluminescence in luminol–H2O2–KSCN–CuSO4 system using (2‐hydroxyethyl) trimethylammonium hydroxide

Visible oscillating chemiluminescence (CL) of luminol–H₂O₂–KSCN–CuSO₄ was studied using the organic base (2‐hydroxyethyl)trimethylammonium hydroxide. The effect of concentrations of luminol, H₂O₂, KSCN, CuSO₄ and the base were investigated in a batch reactor. This report shows how the concentration of components involved in the oscillating CL system influenced the oscillation period, light amplitude and total time of light emission. The oscillating CL with different bases was also investigated. Results indicated that using 2‐HETMAOH causes regular oscillating CL with nearly the same oscillating period. Copyright © 2008 John Wiley & Sons, Ltd.     

Detection of apoptotic bodies in nickel-treated root apical cells of <Emphasis Type="Italic">Allium cepa</Emphasis>

Nickel, a phytotoxic metal, is easily taken up by plant roots. Excessive Ni in soil can induce programmed cell death in root tips. DNA fragmentation was assessed by deoxyuracyl nick end labeling with fluorescein mediated by terminal deoxynucleotide transferase (TUNEL). In control roots, programmed cell death was observed by using TUNEL assay in the root cap and xylem vessels. At moderate Ni²⁺ concentrations (10–25 µM), cortical cells also showed TUNEL-positive reaction, indicating the Ni-induced cell death. The Ni-induced cell death differs from natural cell death in the appearance of spherical bodies of condensed chromatin and formation of apoptotic bodies. These apoptotic bodies resemble those appearing during animal apoptosis.From Fiziologiya Rastenii, Vol. 52, No. 1, 2005, pp. 151–153.Original English Text Copyright © 2005 by Samadi, Behboodi.This article was presented by the authors in English.     

Characterization of Mycobacterium paratuberculosis p36 Antigen and Its Seroreactivities in Crohn's Disease

Recent data using improved cultural, molecular, and serological techniques have strengthened the association of Mycobacterium paratuberculosis with Crohn's disease, an inflammatory bowel disease (IBD) with unknown etiology. To provide more evidence of an etiological association, antibody reactivities of Crohn's disease patients were tested by immunoblotting against M. paratuberculosis–recombinant antigens. A clone containing a 1,402-bp insert and expressing a 36K-antigen (p36) was analyzed. No homology was found between the deduced amino acid sequence of p36 and any protein sequences compiled in the GenBank indicating that p36 is a novel mycobacterial protein. The reactivity of 199 serum samples was tested against the p36 by immunoblotting technique. Sera from 77 of 89 (86.5%) Crohn's disease patients and 16 of 18 (89%) sera from patients with tuberculosis and leprosy reacted with p36 compared to 5 of 42 (12%) ulcerative colitis and non-IBD control sera (p < 0.0001). In addition, p36 reacted to all sera from 10 normal controls that were Bacillus Calmette-Guerin (BCG)-immunized and only to 10% of 40 normal controls that were not BCG-immunized. The fact that sera from Crohn's disease patients reacted to p36 with the same high frequency as the sera from patients that were exposed to mycobacterial antigens further supports the hypothesis of the mycobacterial etiology in Crohn's disease. Received: 8 January 1998 / Accepted: 18 March 1999