Annelid genomes: Enchytraeus crypticus, a soil model for the innate (and primed) immune system

Abstract

Enchytraeids (Annelida) are soil invertebrates with worldwide distribution that have served as ecotoxicology models for over 20 years. We present the first high-quality reference genome of Enchytraeus crypticus, assembled from a combination of Pacific Bioscience single-molecule real-time and Illumina sequencing platforms as a 525.2 Mbp genome (910 gapless scaffolds and 18,452 genes). We highlight isopenicillin, acquired by horizontal gene transfer and conferring antibiotic function. Significant gene family expansions associated with regeneration (long interspersed nuclear elements), the innate immune system (tripartite motif-containing protein) and response to stress (cytochrome P450) were identified. The ACE (Angiotensin-converting enzyme) — a homolog of ACE2, which is involved in the coronavirus SARS-CoV-2 cell entry — is also present in E. crypticus. There is an obvious potential of using E. crypticus as a model to study interactions between regeneration, the innate immune system and aging-dependent decline.

Abstract

Enchytraeus crypticus is a soil-dwelling annelid worm that has been used over the past two decades as an ecotoxicology model. Here, Mónica Amorim and colleagues present the first genome for E. crypticus. The authors identify a number of expanded gene families, including several involved with innate immunity.