The opportunistic coral pathogen Aspergillus sydowii contains dddP and makes dimethyl sulfide from dimethylsulfoniopropionate.
The ascomycete Aspergillus sydowii is associated with a serious epizootic of sea fan corals in the Caribbean. Corals are rich in the compatible solute, dimethylsulfoniopropionate (DMSP), produced by their symbionts, the dinoflagellate Symbiodinium. As other Aspergillus species can catabolize DMSP, liberating dimethyl sulfide (DMS) in the process, we tested A. sydowii strains, obtained from diseased corals and other environments, for this Ddd(+) phenotype. All the strains, irrespective of their geographical or environmental origins, made DMS from DMSP, and all of them contained homologs (>87% identical) of the dddP gene, which encodes an enzyme that releases DMS from DMSP and which occurs in other Ddd(+) fungi and in some marine bacteria. The dddP gene was likely acquired by the Aspergillus fungi by inter-domain horizontal gene transfer from alpha-proteobacteria.
School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, UK.
Mark
M
Kirkwood
Jonathan D
JD
Todd
Krystal L
KL
Rypien
Andrew W B
AW
Johnston
D000818:Animals; D037421:Anthozoa / Q000382:microbiology*; D001230:Aspergillus / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D017691:Caribbean Region; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D005800:Genes, Fungal; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D013440:Sulfides / Q000378:metabolism*; D013452:Sulfonium Compounds / Q000378:metabolism*
D004271:DNA, Fungal; D013440:Sulfides; D013452:Sulfonium Compounds; C068078:dimethylpropiothetin; C004784:dimethyl sulfide