Rewiring of Glutamine Metabolism Is a Bioenergetic Adaptation of Human Cells with Mitochondrial DNA Mutations

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Phylogenetic analysis of Bacillus sphaericus and development of an oligonucleotide probe specific for mosquito-pathogenic strains

Abstract In non-motile forms of Azospirillum lipoferum isolated from the rhizosphere of rice, polyphenol oxidase activity was observed which correlated with production of a dark-brown pigment. Using a combination of substrate/inhibitor specificity tests, intracellular enzyme extracts of non-motile strains were clearly demonstrated to have a laccase activity by oxidising various o - and p -diphenols. This work is the first report on laccase activity in Azospirillum .     

Identification of killer factor in the yeast genusMetschnikowia

Summary Out of 260Metschnikowia pulcherrima strains isolated from Sardinian grapes and musts, 6 proved to be killer yeasts. Maximal killing effect occurred between 3.6 and 5.2 pH, and with 48h or 72h cultures.     

Merosin-deficient congenital muscular dystrophy: neuropathology case reports

The aims of our study were: to present cases of congenital muscular dystrophy (CMD) with deficiency in merosin and the importance of immunohistochemistry in the diagnosis of merosin-deficient CMD. In four years (1997-2000), we found three patients with merosin-deficient CMD, one of them having an unusual clinical and pathological manifestation of the disease. Muscle biopsies of gastrocnemius or quadriceps muscles were investigated. In addition with the conventional HE staining, indirect immunohistochemistry for merosin, dystrophin, utrophin and for the proteins of the dystrophin associated complex (α,β, γ- sarcoglycans; β-dystroglycan) was performed on cryosections. The findings suggest that there is no correlation between the clinical and histological picture of the disease and the expression of merosin in skeletal muscles. The degree of muscle involvment (assessed by histology) is parallel with the clinical neuromotor deficiency, but not with expression of merosin, which can be absent even in mild cases. The clinical investigations as well as current morphological techniques, only together with immunohistochemistry can differentiate between merosin - deficient CMD and other muscular dystrophy forms.     

Chromosomal mapping of 18S-28S and 5S rRNA genes by two-colour fluorescent in situ hybridization in six sturgeon species.

The number and distribution of the 18S-28S and 5S rRNA (rDNA) gene sequences were examined on mitotic chromosomes of six sturgeon species by two-colour in situ hybridization. Four of the six species, Huso huso, Acipenser stellatus, Acipenser sturio, and Acipenser ruthenus, with about 120 chromosomes, showed from six to eight 18S-28S rDNA signals, while 5S rDNA signals were on only one chromosome pair. The two species with 250-270 chromosomes, Acipenser baerii and Acipenser transmontanus, showed from 10 to 12 18S-28S sites and two chromosome pairs bearing 5S rDNA signals. In all examined species, the rather intense 5S rDNA signals apparently overlapped those of 18S-28S rDNA. These data support the diploid-tetraploid relationships between the two chromosome groups of sturgeons. The close association between the two rDNA families in species belonging to an ancestral fish order, such as Acipenseriformes, supports the hypothesis that the association represents a primitive condition.     

SED1 Gene Length and Sequence Polymorphisms in Feral Strains of Saccharomyces cerevisiae

The SED1 gene (YDR077W), coding for the major cell wall glycoprotein of Saccharomyces cerevisiae stationary-phase cells, contains two blocks of tandem repeat units located within two distinct regions of the nucleotide sequence. A PCR survey of the SED1 open reading frames (ORFs) of 186 previously uncharacterized grape must isolates of S. cerevisiae yielded 13 PCR profiles arising from different combinations of seven SED1 length variants in individuals homozygous or heterozygous for the gene. Comparison of the nucleotide sequences of a group of representatives of each of the seven length variants with those of S288C and the type strain, CBS1171, unequivocally identified them as SED1 alleles and provided evidence for the presence of two minisatellite-like sequences, variable in length, within the ORF of an S. cerevisiae gene. The segregation analyses of the SED1 length variants and other genetic markers in 13 isolates representative of each PCR profile suggested that molecular mechanisms involved in minisatellite expansion and contraction may be responsible for SED1 heterozygosities within a population of homothallic must isolates of S. cerevisiae.     

Structure, enzymatic stability and antitumor activity of sea lamprey GnRH-III and its dimer derivatives

Direct antitumor activity of sea lamprey (Petromyzon marinus) gonadotropin-releasing hormone III (Glp-His-Trp-Ser-His-Asp-Trp-Lys-Pro-Gly-NH(2); lGnRH-III) was described on several tumor cells. To improve the selectivity of antitumor effects without increasing the hormone releasing activity and to enhance the enzymatic stability, lGnRH-III dimers were prepared via disulfide bond formation. Our results demonstrate that the lGnRH-III dimer derivatives exhibited higher antiproliferative effect and enzymatic stability in comparison with the native lGnRH-III, while lower LH-releasing potency was determined. In order to find a correlation between the biological and structural features of these compounds, the conformation of lGnRH-III and its dimer derivatives was determined by ECD, VCD, FT-IR and (1)H NMR.     

An effective method for adenoviral-mediated delivery of small interfering RNA into mesenchymal stem cells

Mesenchymal stem cells (MSCs) promise as a main actor of cell-based therapeutic strategies, due to their intrinsic ability to differentiate along different mesenchymal cell lineages, able to repair the diseased or injured tissue in which they are localized. The application of MSCs in therapies requires an in depth knowledge of their biology and of the molecular mechanisms leading to MSC multilineage differentiation. The knockdown of target genes through small interfering RNA (siRNA) carried by adenoviruses (Ad) represents a valid tool for the study of the role of specific molecules in cell biology. Unfortunately, MSCs are poorly transfected by conventional Ad serotype 5 (Ad5) vectors. We set up a method to obtain a very efficient transduction of rat MSCs with low doses of unmodified Ad5, carrying the siRNA targeted against the mRNA coding for Rb2/p130 (Ad-siRNA-Rb2), which plays a fundamental role in cell differentiation. This method allowed a 95% transduction rate of Ad-siRNA in MSC, along with a siRNA-mediated 85% decrease of Rb2/p130 mRNA and a 70% decrease of Rb2/p130 protein 48 h after transduction with 50 multiplicities of infection (MOIs) of Ad5. The effect on Rb2/p130 protein persisted 15 days after transduction. Finally, Ad-siRNA did not compromise the viability of transduced MSCs neither induced any cell cycle modification. The effective Ad-siRNA-Rb2 we constructed, together with the efficient method of delivery in MSCs we set up, will allow an in depth analysis of the role of Rb2/p130 in MSC biology and multilineage differentiation.     

Cannibalism and protective behavior of eggs in Arctic charr (Salvelinus alpinus)

From video recordings of spawning events, we quantified protective and cannibalistic behavior of Arctic charr occurring immediately after spawning. The number of fish cannibalizing on stray eggs was examined regarding (a) whether more than one male shed milt during the spawning event, that is, whether sperm competition occurred, (b) whether the sperm competition included few or many males, that is, the intensity of sperm competition, and (c) the density of fish at the spawning site. Response behavior toward egg cannibalism was also examined among females and dominant males in order to determine any parental investment toward protecting the eggs after spawning. Cannibalistic behavior was seen in almost 50% of the spawnings, and the multiple spawning events showed the highest numbers of fish cannibalizing on eggs. Both the number of males releasing milt and the number of fish approaching the spawning site were positively correlated with egg cannibalism. Sperm competition was, however, not a prerequisite for egg cannibalism. Although we also observed partial filial cannibalism, protective behavior of eggs was seen both among dominant males and females, suggesting that charr actually conduct parental care.