Dynamics of dsRNA mycoviruses in black Aspergillus populations

TY - JOUR

T1 - Dynamics of dsRNA mycoviruses in black Aspergillus populations

AU - van Diepeningen, Anne D

AU - Debets, Alfons J M

AU - Hoekstra, Rolf F

PY - 2006/6

Y1 - 2006/6

N2 - Approximately 10% of all examined 668 representatives of black Aspergillus species, independent of worldwide location, were infected with double-stranded RNA (dsRNA) mycoviruses. These isometric viruses (25-40 nm diameter) contained a variety of often multiple segments of different dsRNA sizes ranging from 0.8 to 4.4 kb in size. In one strain the virus shows clear visible effects on its host with non-sporulating sectors. We quantified the fitness costs of these and more 'cryptic' virus infections on mycelial growth rate and spore production, and on competitive ability with respect to other strains under different growth conditions. Mycovirus infection proved detrimental in all these measures. The reduced success in interference competition due to mycovirus infection belies co-evolution of mycovirus and host to a mutually beneficial symbiosis, like in killer virus systems in yeast and smut and agrees more to recent infections. For a stable virus infection frequency in the black Aspergillus population, fitness costs and spontaneous loss should be balanced with new infections. Implications of even small viral fitness effects combined with the observed transmission limits for host and mycovirus are discussed.

AB - Approximately 10% of all examined 668 representatives of black Aspergillus species, independent of worldwide location, were infected with double-stranded RNA (dsRNA) mycoviruses. These isometric viruses (25-40 nm diameter) contained a variety of often multiple segments of different dsRNA sizes ranging from 0.8 to 4.4 kb in size. In one strain the virus shows clear visible effects on its host with non-sporulating sectors. We quantified the fitness costs of these and more 'cryptic' virus infections on mycelial growth rate and spore production, and on competitive ability with respect to other strains under different growth conditions. Mycovirus infection proved detrimental in all these measures. The reduced success in interference competition due to mycovirus infection belies co-evolution of mycovirus and host to a mutually beneficial symbiosis, like in killer virus systems in yeast and smut and agrees more to recent infections. For a stable virus infection frequency in the black Aspergillus population, fitness costs and spontaneous loss should be balanced with new infections. Implications of even small viral fitness effects combined with the observed transmission limits for host and mycovirus are discussed.

KW - Aspergillus

KW - RNA Viruses

KW - RNA, Double-Stranded

KW - Spores

U2 - 10.1016/j.fgb.2006.01.014

DO - 10.1016/j.fgb.2006.01.014

M3 - Article

C2 - 16546419

SN - 1087-1845

VL - 43

SP - 446

EP - 452

JO - Fungal Genetics and Biology

JF - Fungal Genetics and Biology

IS - 6

ER -