Summary
Seven genes (madA to madG) are known which effect phototropism in Phycomyces. These genes have been partially ordered with respect to the associated stimulus-response pathway. Mutants affected in these genes serve as useful probes of photosensory transduction processes in this model system. To extend and deepen the analysis of the system, we have constructed a family of 21 double mutants in all combinations for the seven mad genes. A set of seven standard alleles was adopted for this work. The double mutants were isolated from crosses between isogenic single-mutant strains of opposite mating type. After a partial physiologic screening of the progeny, the double mutants were identified by complementation tests using single-mutant strains of known genotype. For all but three of the double mutants, the photogeotropism phenotypes were distinct from those of the respective single-mutant parentals. One triple mutant (madA madB madC) was constructed as part of this work. Various applications of the double mutants and the triple mutant are discussed. Recombination analyses were performed on the progeny from seven mad crosses to complete an earlier study. The results establish that all seven mad genes are unlinked.
Similar content being viewed by others
References
Bergman, K., Burke, P.V., Cerdá-Olmedo, E., David, C.N., Delbrück, M., Foster, K.W., Goodell, E.W., Heisenberg, M., Meissner, G., Zalokar, M., Dennison, D.S., Shropshire, W.: Phycomyces. Bacteriol. Rev. 33, 99–157 (1969)
Bergman, K., Eslava, A.P., Cerdá-Olmedo, E.: Mutants of Phycomyces with abnormal phototropism. Mol. Gen. Genet. 123, 1–16 (1973)
Cerdá-Olmedo, E.: Behavioral genetics of Phycomyces. Ann. Rev. Microbiol. 31, 535–547 (1977)
Cerdá-Olmedo, E., Torres-Martinez, S.: Genetics and regulation of carotene biosynthesis. Pure Appl. Chem. 51, 631–637 (1979)
Eslava, A.P., Alvarez, M.I., Lipson, E.D., Presti, D., Kong, K.: Recombination between mutants of Phycomyces with abnormal phototropism. Mol. Gen. Genet. 147, 235–241 (1976)
Foster, K.W., Lipson, E.D.: The light growth response of Phycomyces. J. Gen. Physiol. 62, 590–612 (1973)
Galland, P., Russo, V.E.A.: Photoinitiation of sporangiophores in Phycomyces mutants deficient in phototropism and in mutants lacking β-carotene. Photochem. Photobiol. 29, 1009–1014 (1979)
Heisenberg, M., Cerdá-Olmedo, E.: Segregation of heterokaryons in the asexual cycle of Phycomyces. Mol. Gen. Genet. 102, 187–195 (1968)
Jayaram, M., Presti, D., Delbrück, M.: Light-induced carotene synthesis in Phycomyces. Experimental Mycology 3, 42–52 (1979)
Jayaram, M., Leutwiler, L., Delbrück, M.: Light-induced carotene synthesis in mutants of Phycomyces with abnormal phototropism. Photochem. Photobiol., in press (1980)
Lipson, E.D.: White noise analysis of Phycomyces light growth response system. I. Normal intensity range. Biophys. J. 15, 989–1011 (1975a)
Lipson, E.D.: White noise analysis of Phycomyces light growth response system. II. Extended intensity ranges. Biophys. J. 15, 1013–1031 (1975b)
Lipson, E.D.: White noise analysis of Phycomyces light growth response system. III. Photomutants. Biophys. J. 15, 1033–1045 (1975c)
Lipson, E.D.: Sensory transduction in Phycomyces photoresponses. In: The blue light syndrome (H. Senger, ed.) pp. 110–118. Berlin-Heidelberg-New York: Springer 1980
Lipson, E.D., Terasaka, D.T.: Photogeotropism in Phycomyces double mutants. Manuscript in preparation (1980)
Lopez-Diaz, I., Cerdá-Olmedo, E.: Relationship of photocarotenogenesis to other behavioral and regulatory responses in Phycomyces. Planta, in press (1980)
Medina, J.R., Cerdá-Olmedo, E.: Allelic interaction in the photogeotropism of Phycomyces. Experimental Mycology 1, 286–292 (1977)
Ootaki, T.: A new method for heterokaryon formation on Phycomyces. Mol. Gen. Genet. 121, 49–56 (1973)
Ootaki, T., Lighty, A.C., Delbrück, M., Hsu, W.J.: complementation between mutants of Phycomyces deficient with respect to carotenogenesis. Mol. Gen. Genet. 121, 57–70 (1973)
Ootaki, T., Fischer, E.P., Lockhart, P.: Complementation between mutants of Phycomyces with abnormal phototropism. Mol. Gen. Genet. 131, 233–246 (1974)
Ootaki, T., Kinno, T., Yoshida, K., Eslava, A.P.: Complementation between Phycomyces mutants of mating type (+) with abnormal phototropism. Mol. Gen. Genet. 152, 245–251 (1977)
Sutter, R.P.: Mutations affecting sexual development in Phycomyces blakesleeanus. Proc. Nat. Acad. Sci. USA 72, 127–130 (1975)
Author information
Authors and Affiliations
Additional information
Communicated by G. Melchers
Rights and permissions
About this article
Cite this article
Lipson, E.D., Terasaka, D.T. & Silverstein, P.S. Double mutants of Phycomyces with abnormal phototropism. Molec. Gen. Genet. 179, 155–162 (1980). https://doi.org/10.1007/BF00268458
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00268458