Biological dynamics and distribution of 3‐hydroxy fatty acids in the yeast Dipodascopsis uninucleata as investigated by immunofluorescence microscopy. Evidence for a putative regulatory role in the sexual reproductive cycle¹

Abstract

Dipodascopsis uninucleata has been recently shown to produce 3-hydroxy polyenoic fatty acids from several exogenous polyenoic fatty acids. In order to examine whether endogenous 3-hydroxy fatty acids (3-OH-FA) may be implicated in the developmental biology of this yeast, we mapped by immunofluorescence microscopy their occurrence in fixed cells with or without cell walls using an antibody raised against 3R-hydroxy-5Z,8Z,11Z,14Z-eicosatetraenoic acid (3R-HETE), the biotransformation product from arachidonic acid (AA). This antibody turned out to cross-react with other 3-OH-FA. 3-OH-FA were detected in situ in gametangia, asci, as well as between released ascospores, and proved to be associated with the sexual reproductive stage of the life cycle of the yeast. Acetylsalicylic acid (1 mM), which is known to suppress the formation of 3-OH-FA from exogenous polyenoic fatty acids, inhibited the occurrence of immunoreactive material as well as the sexual phase of the life cycle suggesting a prominent regulatory role of 3-OH-FA for the latter.z 1998 Federation of European Biochemical Societies.

Aspergillus Cyclooxygenase-Like Enzymes Are Associated with Prostaglandin Production and Virulence

“…Although many studies have focused on C 18 oxylipins, several experiments have revealed that both pathogenic and nonpathogenic fungal species produce detectable amounts of both C 20 cyclooxygenase and lipoxygenase products (36,44,45). The arachidonic acid metabolites PGF 2 and PGF 2 -lactone have been detected in a number of environmental yeasts of the family Lipomycetaceae (Dipodascopsis, Lipomyces, Myxozyma, and Zygozyma) (22,33,34,55) as well as in Saccharomyces cerevisiae (33). The pathogenic yeasts Cryptococcus neoformans and Candida albicans and the filamentous fungus A. fumigatus produce both PGs and leukotrienes, and their amounts are significantly increased after exogenous application of arachidonic acid (44,45).…”

Endogenous Lipogenic Regulators of Spore Balance in Aspergillus nidulans

“…With the characterization of ppoA and ppoC, we provide evidence of an endogenous system balancing meiospore and mitospore production in A. nidulans. Orthologs of both of these genes are found in filamentous fungi and, coupled with the numerous studies linking oxylipin production with fungal sporulation (27,31,33,42,51), support a case for conservation of an oxylipin-driven mechanism controlling, among other cellular processes, sexual and asexual differentiation. We propose that fungal oxylipins serve as autocrine or paracrine signals generated in response to-and enabling the fungus to respond appropriately to-specific environmental parameters.…”

Oxylipin Associated Co-Flocculation in Yeasts

“…It is interesting to note that the specific 3-OH oxylipin species present are different depending on the strains and the growth conditions (Table II) It is now necessary to produce significant amounts of pure 3-OH 8:0, either through biotechnological processes using the appropriate yeast strain, or through chemical procedures 5,8 , and determine whether the addition of this oxylipin will uplift the inhibitory effect of aspirin, or perhaps enhance co-flocculation. This would be of importance to the fermentation industry where control of flocculation (i.e.…”

“…Immunofluorescence of co-flocculating cells (Table I: G-J) were performed as described 8 . This included treatment with the primary antibody against 3-OH oxylipins as well as FITC conjugated secondary antibody.…”