TY  - JOUR
A1  - Brunk, Michael
A1  - Sputh, Sebastian
A1  - Doose, Sören
A1  - van de Linde, Sebastian
A1  - Terpitz, Ulrich
T1  - HyphaTracker: An ImageJ toolbox for time-resolved analysis of spore germination in filamentous fungi
JF  - Scientific Reports
N2  - The dynamics of early fungal development and its interference with physiological signals and environmental factors is yet poorly understood. Especially computational analysis tools for the evaluation of the process of early spore germination and germ tube formation are still lacking. For the time-resolved analysis of conidia germination of the filamentous ascomycete Fusarium fujikuroi we developed a straightforward toolbox implemented in ImageJ. It allows for processing of microscopic acquisitions (movies) of conidial germination starting with drift correction and data reduction prior to germling analysis. From the image time series germling related region of interests (ROIs) are extracted, which are analysed for their area, circularity, and timing. ROIs originating from germlings crossing other hyphae or the image boundaries are omitted during analysis. Each conidium/hypha is identified and related to its origin, thus allowing subsequent categorization. The efficiency of HyphaTracker was proofed and the accuracy was tested on simulated germlings at different signal-to-noise ratios. Bright-field microscopic images of conidial germination of rhodopsin-deficient F. fujikuroi mutants and their respective control strains were analysed with HyphaTracker. Consistent with our observation in earlier studies the CarO deficient mutant germinated earlier and grew faster than other, CarO expressing strains.
KW  - bioinformatics
KW  - cell growth
KW  - fungal biology
KW  - microscopy
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-221691
VL  - 8
ER  - 
TY  - JOUR
A1  - García-Martínez, Jorge
A1  - Brunk, Michael
A1  - Avalos, Javier
A1  - Terpitz, Ulrich
T1  - The CarO rhodopsin of the fungus Fusarium fujikuroi is a light-driven proton pump that retards spore germination
JF  - Scientific Reports
N2  - Rhodopsins are membrane-embedded photoreceptors found in all major taxonomic kingdoms using retinal as their chromophore. They play well-known functions in different biological systems, but their roles in fungi remain unknown. The filamentous fungus Fusarium fujikuroi contains two putative rhodopsins, CarO and OpsA. The gene carO is light-regulated, and the predicted polypeptide contains all conserved residues required for proton pumping. We aimed to elucidate the expression and cellular location of the fungal rhodopsin CarO, its presumed proton-pumping activity and the possible effect of such function on F. fujikuroi growth. In electrophysiology experiments we confirmed that CarO is a green-light driven proton pump. Visualization of fluorescent CarO-YFP expressed in F. fujikuroi under control of its native promoter revealed higher accumulation in spores (conidia) produced by light-exposed mycelia. Germination analyses of conidia from carO\(^{-}\) mutant and carO\(^{+}\) control strains showed a faster development of light-exposed carO-germlings. In conclusion, CarO is an active proton pump, abundant in light-formed conidia, whose activity slows down early hyphal development under light. Interestingly, CarO-related rhodopsins are typically found in plant-associated fungi, where green light dominates the phyllosphere. Our data provide the first reliable clue on a possible biological role of a fungal rhodopsin.
KW  - microbial rhodopsins
KW  - intracellular pH
KW  - membrane proteins
KW  - mutants
KW  - virulence
KW  - channelrhodopsin-2
KW  - growth
KW  - gene
KW  - expression
KW  - bacteriorhodopsin
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-149049
VL  - 5
IS  - 7798
ER  -