The A kinase pathway and the MAP kinase pathway converge on a target, the FLO11 gene. The FLO11 gene has an extremely large promoter, which appears to integrate the signals from both the A kinase and MAP kinase pathways. Flo11p is a surface glycoprotein that is required for both filamentation and invasion. The human pathogen, Candida albicans, which grows either as a yeast or filamentous form, has similar control circuitry to that of Saccharomyces . Wild type strains of Candida are virulent in a mouse model.
Plants bend towards the center of the earth in response gravity.
The roots of eir1 mutants are agravitropic and fail to grow downward. The EIR1 gene of Arabidopsis , a member of a family of plant genes with similarities to membrane transporters, is expressed only in the root. The eir1 roots are insensitive to high concentrations of internal IAA and fail to induce an IAA-inducible gene in the expansion zone. Expression of the EIR1 gene in Saccharomyces cerevisiae confers resistance to fluorinated indolic compounds. Other root mutants have been isolated that reveal the pathway of primary and lateral root formation. .