title: Identification and characterization of an Aspergillus fumigatus "supermater" pair.
abstract: The mating efficiency of 50 Aspergillus fumigatus isolates from both clinical and environmental sources was analyzed. Forty isolates completed the sexual cycle in 4 weeks with variable levels of fertility designated high, medium, or low. Two opposite-mating-type strains exhibiting the highest fertility, AFB62 (MAT1-1), isolated from a case of invasive aspergillosis, and AFIR928 (MAT1-2), isolated from the environment, were chosen as the supermater pair. Single cleistothecia obtained from a cross of the two strains harbored a minimum of 1 × 10(4) ascospores. The viability of ascospores increased with the age of the fruiting body, 17% at 4 weeks and reaching 95% at 20 weeks. AFB62 and AFIR928 were equally virulent in two different murine models, despite differences in their sources. High recombination frequencies were observed when the closely linked genes alb1 (AFUA_2G17600) and abr2 (AFUA_2G17530) were used as genetic markers. Comparative genome hybridization analyses revealed that only 86 genes (ca. 0.86% of the genome) are significantly diverged between AFB62 and AFIR928. The high fertility in a relatively short period, combined with a high degree of virulence and a high recombination frequency, demonstrates that the mating pair AFB62 and AFIR928 provides an excellent tool for genetic studies of A. fumigatus.
  
  
  OBJECTIVE
  Aspergillus fumigatus is a heterothallic fungal pathogen that causes life-threatening infections in immunocompromised hosts. Although heterothallism facilitates genetic study via recombinational analysis, previous work showed that a 6-month incubation period is required for the completion of sexual reproduction in this species. Such a long incubation period impedes progress in genetic research. To discover a highly fertile (supermater) pair that can complete the sexual cycle in a considerably shorter period, we screened 50 strains collected from various geographic regions for mating efficiency. We identified a highly virulent pair of supermaters that can be an invaluable tool for genetic study.
authors: Molecular Microbiology Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.
authors: Janyce A
authors: JA
authors: Sugui
authors: Liliana
authors: L
authors: Losada
authors: Wei
authors: W
authors: Wang
authors: John
authors: J
authors: Varga
authors: Popchai
authors: P
authors: Ngamskulrungroj
authors: Mones
authors: M
authors: Abu-Asab
authors: Yun C
authors: YC
authors: Chang
authors: Céline M
authors: CM
authors: O'Gorman
authors: Brian L
authors: BL
authors: Wickes
authors: William C
authors: WC
authors: Nierman
authors: Paul S
authors: PS
authors: Dyer
authors: Kyung J
authors: KJ
authors: Kwon-Chung
mesh_terms: D000818:Animals; D001228:Aspergillosis / Q000382:microbiology*; D001232:Aspergillus fumigatus / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity / Q000502:physiology*; D005656:Fungal Proteins / Q000235:genetics; D049770:Genes, Mating Type, Fungal; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D013172:Spores, Fungal / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology; D014774:Virulence
chemical_list: D005656:Fungal Proteins