Molecular Phylogenetics of Trematode Parasites

Molecular phylogenetics has transformed our understanding of trematodes, a class of parasitic flatworms with complex life cycles that exploit molluscan, vertebrate and sometimes avian hosts. By analysing sequence data from mitochondrial and nuclear loci, researchers can resolve evolutionary relationships that are often obscured by morphological convergence or cryptic speciation. Key markers include mitochondrial genes such as cytochrome c oxidase subunit 1 and internal transcribed spacers of ribosomal RNA. Phylogenomic approaches, combining multiple protein-coding genes or whole mitochondrial genomes, have clarified the placement of major trematode clades and revealed instances of host-driven diversification. These studies underpin taxonomic revisions, inform epidemiological surveillance by distinguishing zoonotic species, and guide control strategies in both medical and agricultural contexts. Integrative analyses have also highlighted the role of environmental factors in shaping parasite communities and the potential for spillover events to drive atypical tissue tropism. The global distribution of trematodes, together with their economic and public health impact, underscores the need for robust molecular frameworks to track transmission, assess biodiversity and predict emerging risks.

Research from Nature Portfolio

Recent molecular analyses of digenean parasites recovered from cattle egrets in Egypt have provided the first combined morphological and mitochondrial sequence data for two genera in the Renicolidae. By sequencing key mitochondrial regions and integrating histopathological observations, this work has clarified the phylogenetic position of Renicola and Apharyngostrigea species and demonstrated distinct genetic lineages correlating with host organ tropism. The study has enriched reference databases and provided a template for assessing parasite evolution in wild bird reservoirs, thereby improving our understanding of host-parasite dynamics at the interface of wildlife and agriculture.

Molecular Phylogenetics of Trematode Parasites publication trend

The graph below shows the total number of articles in molecular phylogenetics of trematode parasites across all publications each year (not limited to Nature Index journals).

Technical terms

Molecular phylogenetics: The use of DNA or protein sequence data to reconstruct evolutionary relationships among organisms.

Cytochrome c oxidase subunit 1 (cox1): A mitochondrial gene frequently used as a barcode marker for species identification and phylogenetic analysis.

Internal transcribed spacer (ITS): Non-coding regions in rRNA operons that vary in length and sequence, useful for distinguishing closely related species.

DNA metabarcoding: A high-throughput technique that uses universal primers to amplify and sequence mixed DNA from environmental or host samples to detect multiple taxa simultaneously.

Haplotype: A group of alleles or sequence variants at adjacent loci on a chromosome that are inherited together and used to infer population structure and evolutionary history.

References

1. High Prevalence of Echinostoma mekongi Infection in Schoolchildren and Adults, Kandal Province, Cambodia - Volume 30, Number 3—March 2024 - Emerging Infectious Diseases journal - CDC. Emerging Infectious Diseases (2024).
2. The phylogenetic position and analysis of Renicola and Apharyngostrigea species isolated from Cattle Egret (Bubulcus ibis). Scientific Reports (2023).
3. Parasite spillover rather than niche expansion explains infection of host brain by diplostomid eye flukes. Proceedings of the Royal Society B (2025).
4. A fine‐scale phylogenetic assessment of digenean trematodes in central Alberta reveals we have yet to uncover their total diversity. Ecology and Evolution (2019).