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P Spellman

Publications and source records attributed to P Spellman.

6 recordsLinked to original sources

Minimum information about a microarray experiment (MIAME)-toward standards for microarray data.

Microarray analysis has become a widely used tool for the generation of gene expression data on a genomic scale. Although many significant results have been derived from microarray studies, one limitation has been the lack of standards for presenting and exchanging such data. Here we present a proposal, the Minimum Information About a Microarray Experiment (MIAME), that describes the minimum information required to ensure that microarray data can be easily interpreted and that results derived from its analysis can be independently verified. The ultimate goal of this work is to establish a standard for recording and reporting microarray-based gene expression data, which will in turn facilitate the establishment of databases and public repositories and enable the development of data analysis tools. With respect to MIAME, we concentrate on defining the content and structure of the necessary information rather than the technical format for capturing it.

Computational Biology↗

Systematic variation in gene expression patterns in human cancer cell lines.

We used cDNA microarrays to explore the variation in expression of approximately 8,000 unique genes among the 60 cell lines used in the National Cancer Institute's screen for anti-cancer drugs. Classification of the cell lines based solely on the observed patterns of gene expression revealed a correspondence to the ostensible origins of the tumours from which the cell lines were derived. The consistent relationship between the gene expression patterns and the tissue of origin allowed us to recognize outliers whose previous classification appeared incorrect. Specific features of the gene expression patterns appeared to be related to physiological properties of the cell lines, such as their doubling time in culture, drug metabolism or the interferon response. Comparison of gene expression patterns in the cell lines to those observed in normal breast tissue or in breast tumour specimens revealed features of the expression patterns in the tumours that had recognizable counterparts in specific cell lines, reflecting the tumour, stromal and inflammatory components of the tumour tissue. These results provided a novel molecular characterization of this important group of human cell lines and their relationships to tumours in vivo.

Breast↗

Transposition of Tn916 to different sites in the chromosome of Neisseria meningitidis: a genetic tool for meningococcal mutagenesis.

The difficulty in obtaining mutants in pathogenic Neisseria has limited the ability to genetically define determinants responsible for virulence as well as the ability to generate a genetic map. We show that the 16.5kb conjugative transposon Tn916 can be introduced into Neisseria meningitidis on the suicide vectors pAM120 and pAM170. After introduction, Tn916 transposed to different sites in the chromosome of recipient meningococci, apparently at random, and was stably incorporated. Following its integration into the meningococcal chromosome, Tn916 did not appear to readily express its conjugative and transpositional functions. However, chromosomal DNA from Tn916-carrying meningococci could be used to transform other meningococcal strains to tetracycline resistance. These studies indicate that Tn916 may be an important tool for genetic analysis of N. meningitidis.

Chromosomes↗