Diversity and Phylogeny of Cristamonadea, Parabasalian Symbionts of Termites

The symbiotic relationship between wood-eating termites and hindgut protists is crucial for termite digestion, with protists aiding in lignocellulose degradation. This relationship, dating back to the late Jurassic, resembles the ancestral association between termites and wood roaches, Cryptocercus, established over 150 million years ago. Paraneotermes simplicicornis and Kalotermes flavicollis, members of the Kalotermitidae family, harbor diverse symbiotic communities pivotal for wood digestion and nitrogen fixation. Parabasalians, such as Cristamonadea, exhibit morphological diversity, with some taxa being joeniids, calonymphids, or devescovinids, residing primarily in termite guts. To explore the coevolutionary history and morphological evolution, this study aims to describe devescovinid communities in P. simplicicornis and K. flavicollis using morphological and molecular approaches. Phylogenetic analysis reveals the relationships among Devescovina, Metadevescovina, Macrotrichomonas, and Calonympha. A misidentification of published sequence AB458854 Joenia annectens provides valuable insights into how species are classified, while the discovery of previously unknown symbionts demonstrates the extent of diversity within these ecosystems. Notably, Clade 2 was named Prototermanova, where novel Cristamonadea species were identified, exhibiting genetic and morphological similarities to Devescovina. Similarly, Clade 4 was labelled Trichoterm, where two novel Devescovina species challenged existing taxonomic classifications. DNA sequencing analyses provided additional validation, highlighting the genetic diversity and potential novelty of symbionts within the termite gut. Morphological examination aligns with previously identified genera, and BLAST analysis supports observations of potential novelty in certain symbionts. Protists from P. simplicicornis and K. flavicollis show close relation to Joenia and Devescovina, respectively. This study sheds light on the complexity of termite symbiotic relationships and underscores the need for continued research to fully comprehend protist diversity within termite guts.