Mary B. Berlyn

A Simple Procedure for Localized Mutagenesis Using Nitrosoguanidine

SummaryA method which we call co-mutagenesis is described for the isolation of temperature sensitive and other types of mutations in any specific small region (1–2%) of the bacterial chromosome. The method is based on observations that NG1 induces multiple mutations and that the induced mutations are by and large confined to the DNA at the chromosome replication forks. We report that the isolation of NG induced mutations of a specific gene provides a simultaneous selection for a population of cells which is highly and preferentially mutagenized in that immediate region of the chromosome. We find that over half of the second site mutations recovered from such a mutagenized population are located within one minute of the selected mutation. This approach provides a simple and rapid method of localized mutagenesis which may be applicable to a broad range of organisms.

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.

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.