A High Frequency Mutation Starts Sexual Reproduction in Volvox carteri

Abstract

Abstract Pheromone-initiated sexual reproduction of Volvox carteri f. nagariensis is started by a “spontaneous” generation of sexual male spheroids at a rate of 10-4. As previously suggested, these males are mutants (sexc) which become independent of pheromone-controlled sex-induction. Unequivocal evidence for a mutative event now comes from the observation that the sexc trait is transmitted through cell lineages during embryogenesis, thus confirming earlier morphological analysis, Mutation semms to be restricted to cell division, The high frequency of mutation points to a special enchacing mechanism for whick the possibility of a genome rearrangement is discussed.