DOI: 10.5061/dryad.58gn0
title: Data from: Light sensing by opsins and fungal ecology: NOP-1 modulates entry into sexual reproduction in response to environmental cues

description: Understanding the genetic basis of the switch from asexual to sexual
 lifestyles in response to sometimes rapid environmental changes is one of
 the major challenges in fungal ecology. Light appears to play a critical
 role in the asexual–sexual switch—but fungal genomes harbour diverse light
 sensors. Fungal opsins are homologous to bacterial green-light-sensory
 rhodopsins, and their organismal functions in fungi have not been well
 understood. Three of these opsin-like proteins were widely distributed
 across fungal genomes, but homologs of the Fusarium opsin-like protein
 CarO were present only in plant-associated fungi. Key amino acids,
 including potential retinal binding sites, functionally diverged on the
 phylogeny of opsins. This diversification of opsin-like proteins could be
 correlated with life history-associated differences among fungi in their
 expression and function during morphological development. In Neurospora
 crassa and related species, knockout of the opsin NOP-1 led to a phenotype
 in the regulation of the asexual–sexual switch, modulating response to
 both light and oxygen conditions. Sexual development commenced early in
 ∆nop-1 strains cultured in unsealed plates under constant blue and white
 light. Furthermore, comparative transcriptomics showed that the expression
 of nop-1 is light-dependent and that the ∆nop-1 strain abundantly
 expresses genes involved in oxidative stress response, genes enriched in
 NAD/NADP binding sites, genes with functions in proton transmembrane
 movement and catalase activity, and genes involved in the homeostasis of
 protons. Based on these observations, we contend that light and oxidative
 stress regulate the switch via light-responsive and ROS pathways in model
 fungus N. crassa and other fungi.
description: FigS2_nop1_phenotypesTriplet crossing plates between the wild type strains (A and B) and between the nop-1 knockout and the wild type strains (C and D) when cultured under constant light with sealed (A and C) and unsealed plates (B and D). Wild type crosses produced perithecia earlier when cultured under constant white light on sealed plates (A) than when cultured under constant white light on unsealed plates (B). matA ∆nop-1 cross with mata wild type exhibited wild type perithecial development when cultured under constant white light on sealed plates (C), but exhibited earlier and more abundant production of perithecia for ∆nop-1 when cultured under constant white light on unsealed plates (D). Conidiation (visible as orange pigment) is much more abundant on unsealed plates in all comparisonsFungal opsin sequences analyzedSequences used in the evolutionary analysesTableS1_sequences.docxTableS4_Bagel_Dunlap_MBE_newResults of BAGEL analyses for microarray data GSE8932. Relative gene expression analysis of 10 microarrays from Chen et al. (2009). Abbreviations: WT: wild type, nop: nop-1 knockout, Ref: pooled RNA reference, D: dark (DD), S: short light exposure (15–30 minutes, LL15, LL30), and L: long light exposure (60–120 minutes, LL60 and LL120).TableS4_Bagel_Dunlap_MBE.csv