Transcriptomics reveal immune downregulation of newts overwhelmed by chytrid co-infection
Alexander Shepack1, Alessandro Catenazzi1
1Department of Biological Sciences, Florida International University, Miami, FL, USA.
Abstract:
What happens when two emergent diseases infect the same host? In a From the Cover article in this issue of Molecular Ecology, McDonald et al. (2020) compare transcriptomic responses to co-infection by the two chytrid fungi in the skin, liver and spleen of Eastern newts (Notophthalmus viridescens). Novel molecular tools, such as high-throughput DNA sequencing for genome discovery and transcriptomics, have revolutionized our understanding of host-pathogen interactions and disease ecology (Güimil et al. 2005; Rosenblum et al. 2012). For example, epidemiologists are using genomic data to track the spread of the emergent SARS-CoV-2 in real time, both locally and globally. RNA sequencing (RNA-Seq) is routinely employed to study response to disease in humans, improving disease diagnostics, profiling and development of intervention strategies. Transcriptomic profiles may be particularly informative for emergent diseases, whose pathologies and effect on host phenotype are poorly known. Fungal pathogens increasingly threaten a variety of wild and domesticated organisms (Fisher et al. 2012), and two chytrid fungi attacking amphibians are causing one of the worst losses of vertebrate biodiversity ever recorded (Scheele et al. 2019).
Insights
Investigating co-infections by two chytrid fungi in Eastern newts reveals distinct transcriptomic responses in skin, liver, and spleen. This research enhances understanding of host-pathogen interactions during emergent fungal diseases.
Area of Science:
- Amphibian disease ecology
- Host-pathogen interactions
- Molecular ecology
Background:
- Emergent infectious diseases pose significant threats to wildlife populations.
- Fungal pathogens, particularly chytrid fungi, have caused severe amphibian biodiversity loss.
- Transcriptomics offers novel insights into host responses to pathogens.
Discussion:
- This study compares transcriptomic profiles of Eastern newts (Notophthalmus viridescens) experiencing single versus co-infections with two chytrid fungi.
- Analysis focused on skin, liver, and spleen tissues to identify differential gene expression patterns.
- RNA sequencing (RNA-Seq) was employed to capture a comprehensive view of the host's molecular response.
Key Insights:
- Co-infection by chytrid fungi elicits distinct transcriptomic responses compared to single infections.
- Specific tissues exhibit unique patterns of gene expression modulation under different infection scenarios.
- Transcriptomic data provides critical insights into the host's physiological and immunological adjustments to multiple pathogens.
Outlook:
- Further research can explore the long-term consequences of co-infections on amphibian populations.
- This work can inform conservation strategies by detailing host vulnerability and disease progression.
- Comparative transcriptomics can be applied to other emergent diseases affecting wildlife and domesticated organisms.
