EMMA—mouse mutant resources for the international scientific community

The laboratory mouse is the premier animal model for studying human disease and thousands of mutants have been identified or produced, most recently through gene-specific mutagenesis approaches. High throughput strategies by the International Knockout Mouse Consortium (IKMC) are producing mutants for all protein coding genes. Generating a knock-out line involves huge monetary and time costs so capture of both the data describing each mutant alongside archiving of the line for distribution to future researchers is critical. The European Mouse Mutant Archive (EMMA) is a leading international network infrastructure for archiving and worldwide provision of mouse mutant strains. It operates in collaboration with the other members of the Federation of International Mouse Resources (FIMRe), EMMA being the European component. Additionally EMMA is one of four repositories involved in the IKMC, and therefore the current figure of 1700 archived lines will rise markedly. The EMMA database gathers and curates extensive data on each line and presents it through a user-friendly website. A BioMart interface allows advanced searching including integrated querying with other resources e.g. Ensembl. Other resources are able to display EMMA data by accessing our Distributed Annotation System server. EMMA database access is publicly available at http://www.emmanet.org

hSAGEing: An Improved SAGE-Based Software for Identification of Human Tissue-Specific or Common Tumor Markers and Suppressors

SAGE (serial analysis of gene expression) is a powerful method of analyzing gene expression for the entire transcriptome. There are currently many well-developed SAGE tools. However, the cross-comparison of different tissues is seldom addressed, thus limiting the identification of common- and tissue-specific tumor markers.To improve the SAGE mining methods, we propose a novel function for cross-tissue comparison of SAGE data by combining the mathematical set theory and logic with a unique “multi-pool method” that analyzes multiple pools of pair-wise case controls individually. When all the settings are in “inclusion”, the common SAGE tag sequences are mined. When one tissue type is in “inclusion” and the other types of tissues are not in “inclusion”, the selected tissue-specific SAGE tag sequences are generated. They are displayed in tags-per-million (TPM) and fold values, as well as visually displayed in four kinds of scales in a color gradient pattern. In the fold visualization display, the top scores of the SAGE tag sequences are provided, along with cluster plots. A user-defined matrix file is designed for cross-tissue comparison by selecting libraries from publically available databases or user-defined libraries

Yeast-like growth of <i>Mucor alternans</i> (van Tieghem) in tissue-culture medium 199

Mucor alternans (van Tieghem) was found to be a diphasic species in that it grew exclusively in the yeast-like budding phase under anaerobic conditions in the complex medium yeast extract – peptone – glucose broth and in tissue-culture medium 199. In the latter medium this growth form occurred also at 37C, at an initial pH of 7.2, and at glucose concentrations of 0.1 and 1.0%. The authors suggest that because of its synthetic nature the tissue-culture medium could be used with advantage in the study of nutritional requirements of dimorphic mucors. </jats:p

Relative lack of Epstein Barr virus (EBV) receptors on B cells from persistently EBV seronegative adults.

Abstract Viral receptors are essential for the entry of the virus into the cell. EBV receptors can be detected on fresh lymphocytes by a technique that uses EBV-coupled tanned red blood cells that form rosettes with lymphocyte-bearing receptors. This technique was found to detect viral receptors only and not surface immunoglobulins. T cell depletion of the lymphocyte population showed that these receptors were present on B lymphocytes. Study of the presence of these EBV receptors on the surface of fresh lymphocytes from 66 subjects (age 2 to 66), selected out of a group of over 2000 individuals, showed that the majority of these donors had receptors for the virus. However, a few of these adults persistently failed to develop anti-EBV antibodies, even if they were in close contact with the infectious agent. The lymphocytes of 11 such individuals were found to be lacking EBV receptors. Transformation assay of these lymphocytes did not give rise to lymphoblastoid cell lines whereas lymphocytes from 4 individuals, who were EBV seropositive or seronegative but receptor positive, yielded permanent lymphoblastoid cell lines. This would suggest that a few EBV seronegative adults (less than 0.5%) display natural resistance to EBV transformation of their lymphoid cells as a result of absolute or relative lack of EBV receptors on these cells.</jats:p

Formation and possible functions of alpha-putrescinylthymine in bacteriophage phi W-14 DNA: analysis of bacteriophage mutants with decreased levels of alpha-putrescinylthymine in their DNAs

The DNA synthesized in the nonpermissive host by the noncomplementing mutants am36 and am42 of bacteriophage phi W-14 contains about half the wild-type level of alpha-putrescinylthymine (putThy) and a correspondingly greater level of thymine. The mechanisms whereby thymine nucleotides are excluded from replicating DNA are functional in both mutants because neither of them incorporates exogenous thymidine into DNA. It is proposed that (i) in wild-type phi W-14, the conversion of hydroxymethyluracil to putThy at the polynucleotide level is sequence specific, but that to thymine is nonspecific; and (ii) in the mutants, the sequence-specific recognition is impaired so that more thymine and less putThy are formed. The thymine-rich DNA can be packaged into phage particles. In the case of am42, the phage particles are morphologically indistinguishable from and have essentially the same polypeptide composition as wild-type particles. However, the DNA molecules they contain are about 11% shorter than those in wild-type phage, am42rev4, a revertant of am42, contains DNA with about 70% of the normal level of putThy; these molecules are about 3% shorter than wild-type DNA. The properties of am42 and am42rev4 are consistent with the suggestion that putThy facilitates the very tight packing of phi W-14 DNA (Scraba et al., Virology 124:152-160, 1983). It also appears that the putThy content of phi W-14 DNA can be reduced by no more than 30% without adversely affecting the production of viable progeny; for example, the burst size of am42rev4 is about 25% of that of the wild type.</jats:p

Carte politique de St Domingue / rédigée d'après le nouveau sistème colonial des citoyens Levassor, Leyritz et Bourjolly, colons ; Viller delt.

Échelle(s) : [1:1 750 000 environ