Temporal genetic mapping of the blue-green alga, Anacystis nidulans.

HE blue-green algae are complex procaryotic organisms, genetic studies of Twhich might yield insight into the relationship between procaryotes and eucaryotes. Due to difficulties commonly encountered in growing blue-green algae on agar plates (ALLEN 1952; KUMAR 1962) and the apparent lack of an operational sexual system, genetic data on these organisms could not be established. However, this report describes an alternate approach to genetic mapping for Anacystis niduZans, an obligate photoautotrophic, unicellular blue-green alga (KRATZ and MYERS 1955). The method employed is similar to those which have been recently applied to heterotrophic bacteria ( STONEHILL and HUTCHISON 1966; ALTENBERN 1966; CERDA-OLMEDO, HANAWALT and GUEROLA 1968). The resulting genetic map is in fact a temporal map of specific marker mutation frequency doubling, observed when successive aliquots of synchronous cultures are treated with a fixed dose of a nonspecific mutagen for a fixed duration.