The Genome of the Chiton Acanthopleura granulata A Model System for Studying Molluscan Biomineralization


Meeting Abstract

P2-206  Saturday, Jan. 5 15:30 – 17:30  The Genome of the Chiton Acanthopleura granulata: A Model System for Studying Molluscan Biomineralization VARNEY, RM*; SPEISER, DI; KOCOT, KM; Univ. of Alabama; Univ. of South Carolina; Univ. of Alabama rvarney@crimson.ua.edu

Chitons (Polyplacophora) are a group of marine molluscs with remarkable biomineralization capabilities. Chitons graze on algae by scraping rocks with a toothed organ called the radula. Feeding is facilitated by teeth coated with iron (magnetite), offering abrasion resistance without compromising flexibility. Rather than a single shell, chitons bear eight valves composed of aragonite. Embedded within the valves are sensory organs known as aesthetes. In Acanthopleura granulata, the fuzzy chiton, some aesthetes are modified into lensed eyes that provide spatial vision. To better understand the mechanisms of biomineralization in chitons, we sequenced a draft genome of Acanthopleura granulata. A single individual was collected from the Florida Keys and DNA was extracted from foot (muscle) tissue. Sequencing was performed using a hybrid approach with data from the Oxford Nanopore and Illumina HiSeq X platforms, assembled in MaSuRCA. N50, annotation with MAKER, and assessment of completeness with BUSCO indicate that this cost-effective hybrid assembly approach is suitable for producing high-quality draft genomics for integrative biological research. Moving forward, Bionano SAPHYR optical mapping will be employed to further improve assembly quality. This resource will facilitate comparative studies of gene expression in the developing chiton radula to shed light on the genomic basis of their remarkable iron biomineralization. Further, this genome will join fewer than 10 sequenced molluscan genomes and is the first genome from the clade Aculifera (Polyplacophora and Aplacophora, sister group to all other molluscs).

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