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Biomedical subjects

M B Berlyn

Publications and source records attributed to M B Berlyn.

5 recordsLinked to original sources

Genome-related datasets within the E. coli Genetic Stock Center database.

The contents of the E. coli Genetic Stock Center database and the availability in electronic form of the subset of information most relevant to sequence databases are described. The database uses the long-standing Stock Center records (developed and curated by Dr B.J.Bachmann) in describing genotypes of mutant derivatives of E.coli K-12 in terms of alleles, structural mutations, mating type, and plasmids as well as the derivation, names and originators of the strain, and references. The database includes descriptions of mutations, mutation properties, genes, gene properties, and gene products, with EC number identifiers for enzymes. Sequence information is not included, but entries refer to sequence database accession numbers for sequenced regions. A gene is described as a subtype of a more general category of chromosome interval called Site. Since sites are used to describe any chromosomal interval, mapping information is associated with sites. Alleles are described as mutations of those sites and they are not primary map objects, but inherit map position information from the corresponding site description. The database design is intended to preserve richness of detail where it is known and uncertainty of measurements or information as it occurs in order to represent the stock center records as accurately as possible.

Bacterial Proteins

CPROP: a rule-based program for constructing genetic maps.

Gene mapping assigns chromosomal coordinates to genetic loci based on analysis of fragmentary ordering and metric data. In assembling genetic maps, geneticists use rules of inference to derive new facts about order and distance between loci from experimentally derived conclusions about order and distance. They construct comprehensive maps by merging related sets of data and resolving conflicts between them. In this article we describe software that formalizes and automates some of these rules of inference to yield a useful map construction utility called CPROP.

Algorithms

COTRANS: a program for cotransduction analysis.

COTRANS is a program for analyzing cotransduction data. It calculates distances from pairwise cotransduction frequencies, computes crossovers required to obtain each observed recombinant class, and applies rules to draw conclusions about order. The rules are based on the correlation between the frequency of the classes and the number of required crossovers for each possible ordering compatible with the distance calculations. The procedure emulates a geneticist's stepwise analysis of the data by first calculating distances, then looking for obvious three-point ordering conclusions, and finally proceeding to a complete crossover analysis. It reports results from each step of the analysis and an overall conclusion. COTRANS provides significant gains in speed and convenience over hand analysis, particularly for multipoint crosses with several recombinant classes.

Crossing Over, Genetic

A gene encoding the tryptophan synthase beta subunit of Arabidopsis thaliana.

The DNA sequence of a tryptophan synthase gene and the flanking 5' and 3' regions has been determined for Arabidopsis thaliana. The sequence encodes only the beta subunit domain, indicating that alpha and beta subunits are specified by separate genes. The gene contains four introns and encodes 470 amino acid residues. The plant amino acid sequence is highly conserved with respect to corresponding microbial sequences. The NH2-terminal amino acid sequence is characteristic of chloroplast transit peptides. Identity of the sequences of the genomic exons and a cDNA clone and the presence of cellular RNA corresponding in size and 5' sequence to the gene indicate that the gene is expressed. Analysis of Arabidopsis genomic DNA suggests the presence of a second gene for the beta subunit.

Amino Acid Sequence

A mutational approach to the study of photorespiration.

A number of quite different types of variant cell lines of tobacco have been isolated. This multiplicity of approaches has been in part dictated by the uncertainities of the photorespiratory pathway. We are in the process of determining the relationship between the observed alterations and the glycolate pathway. The INH-resistant trait has been observed in callus derived from plants regenerated from the original resistant callus and in cone case from seedlings of the subsequent generation. It is hoped that these cultures and the plants derived from them will further our understanding of photorespiration and will eventually lead to the ability to regulate photorespiration and net photosynthesis in higher plants.

Cells, Cultured