First genome assembly for the apicomplexan class Marosporida from the parasite Margolisiella madlensis infecting the bay scallop

Abstract

Margolisiella madlensis , previously known as bay scallop Marosporida (BSM), is an apicomplexan parasite implicated in recurrent summer mortality of the bay scallop Argopecten irradians in the Northeastern United States. It is a member of the class Marosporida, a major apicomplexan lineage that has so far lacked nuclear genomic resources. Here we report the draft nuclear genome of M. madlensis 23004-MA1, assembled from PacBio HiFi and Illumina sequencing data. The assembly comprises 41.0 Mb in 6,697 scaffolds. Interspersed repeats accounted for 40.3% of the assembly, while repetitive and low-complexity sequences together accounted for 45.8%. To our knowledge, this is the first nuclear genome available for the class Marosporida. Therefore, this genome provides an essential reference for comparative studies of apicomplexan evolution and establishes a basis for future work on parasite biology, molecular detection, and host-parasite interactions in marine invertebrates.