PET1402, a nuclear gene required for proteolytic processing of cytochrome oxidase subunit 2 in yeast

The nuclear mutation pet ts1402 prevents proteolytic processing of the precursor of cytochrome oxidase subunit 2 (cox2) in Saccharomyces cerevisiae. The structural gene PET1402 was isolated by genetic complementation of the temperature-sensitive mutation. DNA sequence analysis identified a 1206-bp open reading frame, which is located 215 by upstream of the PET122 gene. The DNA sequence of PET1402 predicts a hydrophobic, integral membrane protein with four transmembrane segments and a typical mitochondrial targeting sequence. Weak sequence similarity was found to two bacterial proteins of unknown function. Haploid cells containing a null allelle of PET1402 are respiratory deficient.     

Sequence analysis of cohesive ends of the actinophage RP3 genome and construction of a transducible shuttle vector

Abstract The sequence of the cohesive ends of actinophage RP3 DNA has been determined. As with all other phages of Gram-positive bacteria that have been studied sofar, RP3 DNA has 3'-protruding ends. A shuttle cosmid has been constructed containing this cos area which can be efficiently transduced by phage RP3 to host cells of Streptomyces rimosus .     

Improved growth and methane production conditions for Methanobacterium thermoautotrophicum

Methanobacterium thermoautotrophicum was grown on a defined mineral salts medium under strictly anaerobic conditions with H₂ and CO₂ as the sole energy and carbon sources, respectively. The cultivation medium was optimized with respect to non-organic components including Se(IV), W(VI), N, Ni(II), Fe(II), Co(II) and Mo(VI). Sulphide concentration in the medium was maintained constant using an on-line regulatory system by the addition of 0.5 M Na₂S. A maximum supply rate of 0.6 vvm of a mixture of 80% H₂ and 20% CO₂ was achieved for the gaseous substrates. Under these conditions a specific growth rate of 0.30 h^–1 and a cell concentration of 4.8 g cell dry weight (DW) l^–1, representing a 140% increase over previously published results, were obtained. The growth yield of 2.3 g DW mol^–1 CH₄ was similar to published values. However, the overall specific productivity was enhanced from 11 mmol CH₄ g^–1 DW h^–1 to 24 mmol CH₄ g^–1 DW h^–1, corresponding to an improvement of 120%. Correspondence to: U. von Stockar     

Glutamate Dehydrogenase Is Not Essential for Glutamate Formation by Corynebacterium glutamicum

Two Corynebacterium glutamicum strains, one being glutamate dehydrogenase (GDH) negative and the other possessing 11-fold-higher specific GDH activity than the parental wild type, were constructed and used to analyze the role of GDH in C. glutamicum. The results indicate (i) that GDH is dispensable for glutamate synthesis required for growth and (ii) that although a high level of GDH increases the intracellular glutamate pool, the level of GDH has no influence on glutamate secretion.     

Differentiation of species in Gonioloboceras

The type specimen ofGonioloboceras goniolobum (Meek), rediscovered by Spath in the British Museum, is the foundation for a more accurate comparative study of this and other species ofGonioloboceras.Gonioloboceras described asG. goniolobum byElias in 1938 is differentiated asGonioloboceras schmidti, new species. Suture sets (new term) for several growth stages inG. goniolobum (Meek),G. welleriSmith,G. schmidtiElias, G.eliasiMiller &Owen, andG. asiaticumLibrovitch are assembled and used for differentiation of the species.The Kazakhstan goniatite faunule containingG. asiaticum is considered of very late Pennsylvanian age.     

La procréation médicalement assistée avec spermatozoïdes immatures: Impératifs cliniques et techniques chirurgicales

The authors report their experience with the use of spermatids in TESE programs where mature spermatozoa could not be isolated from testicular biopsies. The details of the indications for spermatid insemination, the technicity of the procedure and the results are exposed.     

High-resolution mapping of a linkage group on mouse chromosome 8 conserved on human chromosome 16Q

We have performed a high-resolution linkage analysis for the conserved segment on distal mouse Chromosome (Chr) 8 that is homologous to human Chr 16q. The interspecific backcross used involved M. m. molossinus and an M. m. domesticus line congenic for an M. spretus segment from Chr 8 flanked by phenotypic markers Os (oligosyndactyly) and e, a coat colormarker. From a total of 682 N₂ progeny, the 191 animals revealing a recombination event between these phenotypic markers were typed for 23 internal loci. The following locus order with distances in cM was obtained: (centromere)–Os–4.1–Mmp2–0.2–Ces1,Es1, Es22–1.2–Mt1,D8Mit15–2.2–Got2, D8Mit11–3.7–Es30–0.3–Es2, Es7–0.9–Ctra1,Lcat–0.3–Cdh1, Cadp, Nmor1, D8Mit12–0.2–Mov34–2.5–Hp,Tat–0.2–Zfp4–1.6–Zfp1,Ctrb–10.9–e. In a separate interspecific cross involving 62 meioses, Dpep1 was mapped together with Aprt and Cdh3 at 12.9 cM distal to Hp, Tat, to the vicinity of e. Our data give locus order for markers not previously resolved, add Mmp2 and Dpep1 as new markers on mouse Chr 8, and indicate that Ctra1 is the mouse homolog for human CTRL. Comparison of the order of 17 mouse loci with that of their human homologs reveals that locus order is well conserved and that the conserved segment in the human apparently spans the whole long arm of Chr 16. Received: 30 July 1996 / Accepted: 15 November 1996     

Enhanced quantitative resistance against fungal disease by combinatorial expression of different barley antifungal proteins in transgenic tobacco

cDNAs encoding three proteins from barley ( Hordeum vulgare ), a class-II chitinase (CHI), a class-II β-1,3-glucanase (GLU) and a Type-I ribosome-inactivating protein (RIP) were expressed in tobacco plants under the control of the CaMV 35S-promoter. High-level expression of the transferred genes was detected in the transgenic plants by Northern and Western blot analysis. The leader peptides in CHI and GLU led to accumulation of these proteins in the intercellular space of tobacco leaves. RIP, which is naturally deposited in the cytosol of barley endosperm cells, was expressed either in its original cytosolic form or fused to a plant secretion peptide (spRIP). Fungal infection assays revealed that expression of the individual genes in each case resulted in an increased protection against the soilborne fungal pathogen Rhizoctonia solani , which infects a range of plant species including tobacco. To create a situation similar to 'multi-gene' tolerance, which traditional breeding experience has shown to provide crops with a longer-lasting protection, several of these antifungal genes were combined and protection against fungal attack resulting from their co-expression in planta was evaluated. Transgenic tobacco lines were generated with tandemly arranged genes coding for RIP and CHI as well as GLU and CHI. The performance of tobacco plants co-expressing the barley transgenes GLU/ CHI or CHI/RIP in a Rhizoctonia solani infection assay revealed significantly enhanced protection against fungal attack when compared with the protection levels obtained with corresponding isogenic lines expressing a single barley transgene to a similar level. The data indicate synergistic protective interaction of the co-expressed anti-fungal proteins in vivo .