Obligate Insect-Associated Fungi

Fungi have important roles as insect pathogens and symbionts. Using -omics, we can begin to understand the biology behind these complicated insect-microbe interactions. I have been involved in several projects focused on the genomics of obligate insect-associated fungi. One project involved assisting with removing symbionts or contaminant bacterial genomes from the genome of Massospora cicadina an obligate fungal parasite of cicadas. Another project involved comparative genomics and transcriptomics across development of the blastoclad fungus, Coelomomyces lativittatus, an obligate parasite of mosquitoes and microcrustaceans.

Fig 1 from Ettinger et al 2023 Mycologia


Known Coelomomyces species lack a complete asexual life cycle, instead surviving through an obligate two-host alternation of generations life cycle. To address how little was known about the genomics and biology of these unique fungi, we generated three draft-level genomes and annotations for C. lativittatus representing its haploid meiospore, orange gamete, and amber gamete life stages.

We then used the draft annotations as a reference for analysis of C. lativittatus metatranscriptomes. We analyzed metatranscriptomes from across host-associated life stages, including infected larvae and excised mature sporangia from the mosquito Anopheles quadrimaculatus. We identified differentially expressed genes and enriched GO terms both across and within life stages. Generally, we found the C. lativittatus transcriptome to be a complex and dynamic expression landscape with GO terms related to metabolism and transport processes enriched during infection and terms related to dispersal enriched during sporulation.

Fig 3 from Ettinger et al 2023 Mycologia

C. lativittatus genome annotation enables comparisons to other fungal taxa. From left to right, a phylogeny that shows the relationship of C. lativittatus to other fungal lineages. Next, a bar chart of the draft genome size, followed by predicted gene counts. Next, bar charts of BUSCO “protein” completion status (missing = gray, fragmented = yellow, complete and duplicated = green, complete and single copy = blue).

Related publications:

  • Ettinger CL, Wu-Woods J, Kurbessoian T, Brown D, de Souza Pacheco I, Vindiola BG, Walling LL, Atkinson PA, Byrne FJ, Redak RA & Stajich JE. 2023. Geographical Survey of the Mycobiome and Microbiome of Southern California Glassy-winged Sharpshooters. mSphere. DOI: 10.1128/msphere.00267-23
  • Ettinger CL, Ostovar T, Yacoub M, Ahrendt S, Hice RH, Federici BA, & Stajich JE. 2023. Genomes and transcriptomes help unravel the complex life cycle of the blastoclad fungus, Coelomomyces lativittatus, an obligate parasite of mosquitoes and microcrustaceans. Mycologia. DOI: 10.1080/00275514.2023.2228182
  • Stajich JE, Lovett BR, Ettinger CL, Carter-House D, Kurbessoian T & Kasson MT. 2022. An Improved 1.5 Gigabase Draft Assembly of Massospora cicadina (Zoopagomycota), Obligate Fungal Parasite of 13- and 17-Year Cicadas. Microbial Resource Announcements. DOI: 10.1128/mra.00367-22
  • Ettinger CL, Lovett BR, Kasson MT & Stajich JE. 2022. Metagenome-assembled Genomes of Bacteria associated with Massospora cicadina Fungal Plugs from Infected Brood VIII Periodical Cicadas. Microbial Resource Announcements. DOI: 10.1128/mra.00413-22