Chromosome-level genome assembly of the deep-sea solemyid bivalve Acharax haimaensis
Open Access
- 27 February 2026
- journal article
- research article
- Published by Springer Nature in Scientific Data
- Vol. 13 (1)
Abstract
Solemyidae, an ancient lineage of protobranch bivalves, are characterized by unique morphology and obligate symbiosis with sulfur-oxidizing bacteria, enabling survival in sulfide-rich sediments. However, limited genomic resources have hindered understanding of their evolutionary history, symbiotic interactions, and environmental adaptation. Here, we report a chromosome-level reference genome of Acharax haimaensis, assembled using PacBio, Illumina, and Hi-C sequencing. The 4.27 Gb genome, with a scaffold N50 of 195.52 Mb, was anchored to 22 chromosomes and achieved high completeness (98.2%) based on BUSCO. Transposable elements occupy 50.17% of the assembly, dominated by long interspersed nuclear elements (14.20%). We predicted 38,343 protein-coding genes, of which 87.25% were functionally annotated. Macrosynteny analysis revealed each chromosome comprises two to four segments of ancestral linkage groups, indicating extensive chromosomal breakage and fusion in early bivalve evolution. Phylogenetic inference suggested A. haimaensis diverged from the common ancestor of Autobranchia ~550 Mya. This first deep-sea protobranch genome provides an essential resource for exploring bivalve evolution and the genetic basis of symbiosis and adaptation to extreme environments.Keywords
Funding Information
- National Natural Science Foundation of China (42376058)
- National Natural Science Foundation of China (42221005 to WMX)
- Ministry of Science and Technology of the People's Republic of China (2024YFC2816000)
This publication has 43 references indexed in Scilit:
- Ancient gene linkages support ctenophores as sister to other animalsNature, 2023
- Haplotype-resolved de novo assembly using phased assembly graphs with hifiasmNature Methods, 2021
- Solemyidae (Bivalvia, Protobranchia) from the lower Miocene of south-central Chile, with description of a new speciesJournal of Paleontology, 2020
- Graph-based genome alignment and genotyping with HISAT2 and HISAT-genotypeNature Biotechnology, 2019
- GeMoMa: Homology-Based Gene Prediction Utilizing Intron Position Conservation and RNA-seq Data2019
- BUSCO: Assessing Genome Assembly and Annotation Completeness2019
- Juicer Provides a One-Click System for Analyzing Loop-Resolution Hi-C ExperimentsCell Systems, 2016
- StringTie enables improved reconstruction of a transcriptome from RNA-seq readsNature Biotechnology, 2015
- Into the deep: A phylogenetic approach to the bivalve subclass ProtobranchiaMolecular Phylogenetics and Evolution, 2013
- Characterization and site description of Solemya borealis (Bivalvia; Solemyidae), another bivalve-bacteria symbiosisMarine Biology, 1992