Developmental regulation of CUP gene expression through DNA methylation in Mucor spp

Abstract

Inserts which carried the CUP gene from Saccharomyces cerevisiae or Mucor racemosus were used as hybridization probes to measure the methylation state and expression of the CUP gene from Mucor rouxii at different stages of growth. It was observed that the fungus contains a CUP multigene family. All the CUP genes were present in a hypermethylated DNA region in nongrowing and isodiametrically growing spores and were not transcribed at these stages. After germ tube emergence, CUP genes became demethylated and transcriptionally active. Development, demethylation, and transcription of CUP genes were blocked by the ornithine decarboxylase inhibitor 1,4-diaminobutanone. These results suggest that genes that are activated during development become demethylated in this fungus.The idea that DNA methylation regulates gene expression during the development of different eucaryotic organisms has been gaining ground recently (see references 14 and 26 for reviews). Different but significant levels of 5-methylcytosine have been detected in DNA from several species of fungi (2,23,29,30

The ornithine decarboxylase gene odc is required for alcaligin siderophore biosynthesis in Bordetella spp.: putrescine is a precursor of alcaligin

“…Wild-type B. bronchiseptica B013N was cultured overnight in ironreplete SS, and then bacterial cells from 200 l of culture were harvested by centrifugation, washed twice with 1-ml volumes of iron-depleted SS, and used to seed 20 ml of iron-depleted SS. The resulting suspension was divided among sterile culture tubes, and a 0.5 M stock solution of aqueous DAB, a competitive inhibitor of Odc activity (13), was added to the first tube to provide 2 mM final concentration. DAB was diluted serially 1:5 through the series of culture tubes, yielding starting cultures containing DAB at 2.000, 0.400, 0.080, 0.016, 0.003, and 0.001 mM final concentrations.…”

The putrescine analogue (E)-1,4-diaminobut-2-ene reduces DNA methylation in the plant pathogenic fungus Pyrenophora avenae

“…It has been demonstrated in many biological systems that the state of DNA methylation may regulate gene expression at different developmental stages [7]. Recent research has suggested that polyamines affect the methylation state of DNA [2], and Ruiz‐Herrera [8] has suggested that the role of increased levels of polyamines during development is to inhibit DNA methylation, thus allowing the expression of specific genes. Most recently, Ruiz‐Herrera et al [9] have demonstrated that polyamines selectively inhibit cytosine‐DNA methylases, indicating a possible mode of action of polyamines in vivo.…”

Differences in DNA methylation patterns are detectable during the dimorphic transition of fungi by amplification of restriction polymorphisms

“…We are interested in the role of DNA methylation in fungal development, and have obtained evidence that spore DNA from Mucor rouxii contains more 5mC than the growing hyphae (Cano et al 1988), and that methylation is involved in selective gene expression during spore germination (Cano-Canchola et al 1992). In order to determine how general the phenomenon of differential methylation of fungal DNA during development might be, we have addressed this problem using an adaptation of the recently introduced technique of amplified fragment length polymorphism (AFLP) analysis (Zabeau and Vos 1993;Becker et al 1995;Vos et al 1995).…”