ISSN:
1617-4623
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary Auxotrophs of Serr. marcescens HY, which behaved like nonsense mutants when tested according to Whitfield et al. (1966), were induced to revert to anauxotrophy. Some of the revertants (called su +), together with the parental auxotrophs (called su -), allowed to isolate conditional-lethal (sus) mutants of phage Kappa, which produce infectious progeny only in su + bacteria. All su + mutants of Serr. marcescens HY were identified as nonsense suppressors using su + amber, su + ochre, and su - strains of Salm. typhimurium as references and the flagella-specific phage Chi as the main tool to connect the Salmonella system with that of Serratia. After treatment of Kappa with three different mutagens 128 sus mutants were isolated which comprise at least 19 complementation groups. 18 sus mutants, representing different cistrons, and the unselective markers c1, c2, and c49 were mapped mainly by two-factor crosses. Reciprocal three-factor crosses of the general type a x bz and az x b (i.e. with “outside” markers) revealed a circular linkage map of an estimated maximum length of 90 RU (recombination units). Joined rescue of “outside” markers, e.g. sus + A94 and e49, from UV-irradiated phage supported the assumption of circular gene linkage. Some data indicate that certain regions of the phage genome might have a higher chance to recombine than others.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00340383
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