Sexual recombination in Aspergillus tubingensis

Abstract

Aspergillus tubingensis from section Nigri (black Aspergilli) is closely related to A. niger and is used extensively in the industrial production of enzymes and organic acids. We recently discovered sexual reproduction in A. tubingensis, and in this study we demonstrate that the progeny are products of meiosis. Progeny were obtained from six crosses involving five MAT1-1 strains and two MAT1-2 strains. We examined three loci, including mating type (MAT), RNA polymerase II (RPB2) and β-tubulin (BT2), and found that 84% (58/69) of progeny were recombinants. Recombination associated with sexual reproduction in A. tubingensis provides a new option for the genetic improvement of industrial strains for enzyme and organic acid production.

• Aspergillus niger
• mating type
• multilocus sequence typing
• sexual reproduction

Acknowledgments

We thank Travis Walk for technical assistance. This work was supported by the Agriculture and Food Research Initiative Competitive Grants Program grant No. 2013-68004-20359 from the USDA National Institute of Food and Agriculture (NIFA). RAO was supported by a USDA-NIFA Pre-doctoral fellowship, grant No. 2012-67011-19689.