TY - JOUR TI - Gene regulatory network plasticity predates a switch in function of a conserved transcription regulator AU - Nocedal, Isabel AU - Mancera, Eugenio AU - Johnson, Alexander D A2 - Wittkopp, Patricia J VL - 6 PY - 2017 DA - 2017/03/22 SP - e23250 C1 - eLife 2017;6:e23250 DO - 10.7554/eLife.23250 UR - https://doi.org/10.7554/eLife.23250 AB - The rewiring of gene regulatory networks can generate phenotypic novelty. It remains an open question, however, how the large number of connections needed to form a novel network arise over evolutionary time. Here, we address this question using the network controlled by the fungal transcription regulator Ndt80. This conserved protein has undergone a dramatic switch in function—from an ancestral role regulating sporulation to a derived role regulating biofilm formation. This switch in function corresponded to a large-scale rewiring of the genes regulated by Ndt80. However, we demonstrate that the Ndt80-target gene connections were undergoing extensive rewiring prior to the switch in Ndt80’s regulatory function. We propose that extensive drift in the Ndt80 regulon allowed for the exploration of alternative network structures without a loss of ancestral function, thereby facilitating the formation of a network with a new function. KW - C. albicans KW - P. pastoris KW - S. stipitis KW - K. lactis KW - C. lusitaniae KW - regulatory network JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -