Zebrafish Study Points to tnni2a.3 as a Candidate Gene in Intermuscular

A new zebrafish study published in BMC Genomics points to tnni2a.3 as a candidate gene involved in forming intermuscular bones—small ossified structures within the muscle that can hinder aquaculture processing and affect flesh quality. Using spatial transcriptomics, researchers created an atlas from six transverse sections of intermuscular bone–associated muscle tissue from a single adult zebrafish. With the Visium platform, they quality-controlled 1,406 spots and organized them into 11 tissue domains. Among three tnni2 homologs, tnni2a.3 showed the highest mean expression and was enriched near intermuscular bone regions. Weak domain-specific correlations with type I collagen genes were observed. Independent qRT-PCR validation matched the spatial pattern, and CRISPR/Cas9 disruption in F0 fish reduced intermuscular bone number. The authors caution that the atlas is based on one fish and functional results are preliminary. Published open access on 29 October 2026.