Transcriptomic and genomic analysis of the Chinese mitten crab identified 23 myosin genes and revealed dynamic regulation of myosin expression to support muscle development during larval metamorphosis.
The study identifies 23 myosin genes in the Chinese mitten crab and maps their dynamic expression during metamorphosis, providing insights into crustacean muscle development.
Background The Chinese mitten crab (Eriocheir sinensis) undergoes periodic molting and exhibits discontinuous muscle growth during its larval metamorphosis, yet the underlying molecular drivers remain poorly understood. Myosin, a central motor protein, is crucial for muscle function and diverse cellular processes. Results This study integrated transcriptomic analysis across three key developmental stages (zoea, megalopa, and early juvenile) with a systematic genome-wide characterization of the myosin gene family in E. sinensis. Transcriptomics revealed that myosin genes were dynamically regulated and were among 196 genes continuously upregulated in both the megalopa vs. zoea and early juvenile vs. megalopa comparisons. These co-upregulated genes are involved in tissue remodeling and nutrient metabolism, with functional enrichment highlighting tight junction assembly and actin cytoskeleton regulation. We identified 23 myosin genes (EsinMyos) in the E. sinensis genome, belonging to 11 subfamilies, with a notable representation of the conventional myosin II (Myo2) subfamily, which comprises nine members—a pattern consistent with Myo2 abundance in crustaceans across 42 surveyed animal species. Chromosomal clustering of EsinMyo2 genes on chromosome 35 suggests that tandem duplication event(s) contributed to this phenomenon. Phylogenetic analysis across 42 animal species confirmed the high conservation of myosin classes and revealed the absence of Myo10, Myo16, and Myo28 in all examined arthropods, indicating lineage-specific gene loss. Structural comparison further identified an atypical Myo2, truncated EsinMyo2-1. Expression profiling demonstrated distinct stage-specific patterns for different EsinMyos; for instance, EsinMyo1D and EsinMyo2-8 showed progressively increasing expression from zoea to juvenile, while EsinMyo15 was highest in zoea. Conclusions These findings underscore the pivotal and coordinated role of the myosin gene family in supporting the phase-specific morphological and physiological demands of muscle development and metamorphosis in E. sinensis, providing valuable genetic insights for aquaculture and developmental biology.
Wu et al. (Thu,) conducted a other in Larval metamorphosis and muscle development (n=90). Developmental stage (zoea, megalopa, early juvenile) vs. Zoea stage was evaluated on Identification and expression profiling of the myosin gene family. Transcriptomic and genomic analysis of the Chinese mitten crab identified 23 myosin genes and revealed dynamic regulation of myosin expression to support muscle development during larval metamorphosis.