Proceedings of the National Academy of Sciences of the United States of America 20161212 52
The recent accumulation of newly discovered fungal-bacterial mutualisms challenges the paradigm that fungi and bacteria are natural antagonists. To understand the mechanisms that govern the establishment and maintenance over evolutionary time of mutualisms between fungi and bacteria, we studied a symbiosis of the fungus Rhizopus microsporus (Mucoromycotina) and its Burkholderia endobacteria. We found that nonhost R. microsporus, as well as other mucoralean fungi, interact antagonistically with e ...[more]
Project description:The goal of this study was to identify fungal gene expression changes during early stages of symbiosis establishment with its Burkholderia endosymbionts. Results: Leveraging this RNA-seq dataset we identified fungal genes utilized for symbiosis establishment with bacteria. Overall design: Methods: Host (ATCC 52813) and non-host (ATCC 11559) isolates of R. microsporus were growth alone or in the presence of Burkholderia endobacteria isolated from the host isolate. Fungal mycelia were harvested at a timepoint when the fungal colony has just begun to come into physical contact with the bacteria. Total RNA was extracted, rRNA depleted with RiboZero, and sequenced on the Illumina Hi-Seq 100bp-paired end reads platform
Project description:Through transcriptome profiling using RNA-seq, we investigated the mechanisms behind bacterial endosymbiont (Burkholderia rhizoxinica) control over host (Rhizopus microsporus) reproductive biology. By analyzing differential expression across six different conditions, including fungal opposite mates growing independently with or without endosymbionts, as well as opposite mates growing together with endosymbionts (mating) or without endosymbionts (no mating), we were able to identify that endosymbionts control expression of a Ras signaling protein critical for sexual reproduction in many fungi (Ras2). As little is known regarding sexual reproduction in Mucoromycotina, we also used these data to investigate conservation of sex-related genes across all fungi, as well as predict potential genes involved in sensing of trisporic acid, the mating pheromone used by these fungi. 6 different conditions were analyzed, each consisting of two biological replicates. These included Rhizopus microsporus ATCC52813 (sex +) growing alone with endosymbionts, R. microsporus ATCC52814 (sex -) growing alone with endosymbionts, ATCC 52813 growing alone without endosymbionts, ATCC52814 growing alone without endosymbionts, ATCC52813 and ATCC52814 growing together with endosymbionts (successfully mating), and ATCC52813 and ATCC52814 growing together without endosymbionts (failure to mate). In each condition, fungi were cultivated on half-strength PDA and plugs of mycelium were placed at the edge of the plate. After 6 days, approximately 2.5 cm of tissue were harvested from the center of the plate. Each biological replicate consists of 5 plates which were pooled prior to RNA extraction to ensure sufficient tissue was collected.