Comparative analysis of histological and transcriptomic characteristics in caudal muscles of nile crocodiles (Crocodylus niloticus), siamese crocodiles (Crocodylus siamensis), and their hybrids.

Yunlong Wu; Yanhong Nong; Yanyan Zheng; Shi Fu; Jiayi Liu; Fei Ma; Ying Wang; XiaoJin Liu; Bin Ouyang; Qi Liu; Hai Huang; Zhiqiang Guo; Mei Wang

doi:10.1016/j.cbd.2026.101889

PubMed · 42242154

Comparative analysis of histological and transcriptomic characteristics in caudal muscles of nile crocodiles (Crocodylus niloticus), siamese crocodiles (Crocodylus siamensis), and their hybrids.

Yunlong Wu·Yanhong Nong·Yanyan Zheng·Shi Fu·Jiayi Liu·Fei Ma·Ying Wang·XiaoJin Liu·Bin Ouyang·Qi Liu·Hai Huang·Zhiqiang Guo·Mei Wang

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Abstract

Crocodylus niloticus and Crocodylus siamensis are high-value aquaculture species. C. niloticus is large-bodied but less abundant, while C. siamensis grows fast but is small-sized. Their hybrids combine parental advantages, yet relevant research is scarce. This study compared the histological and transcriptomic characteristics of the caudal muscle across the three taxa. HE staining indicated that C. niloticus had significantly larger myofiber diameters (p < 0.05); C. siamensis had the smallest, and the myofiber density of hybrids was much closer to that of C. siamensis. Masson's trichrome staining indicated that C. niloticus had the thickest collagen fibers (p < 0.05), C. siamensis the thinnest, and hybrids exhibited highly similar histological traits to C. siamensis. C. niloticus had higher LDH and SDH activities in caudal muscles, whereas the hybrid crocodile indicated the highest CK activity. Transcriptomic analysis identified numerous differentially expressed genes (DEGs), which were enriched in growth, muscle metabolism, and energy allocation pathways via GO/KEGG annotations. PPI analysis screened 24 hub genes related to energy metabolism. This study systematically reveals caudal muscle differences, providing insights into growth-related molecular mechanisms and theoretical support for crocodile artificial breeding.

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Animals Alligators and Crocodiles Transcriptome Muscle, Skeletal Gene Expression Profiling Crocodylus niloticus Crocodylus siamensis Histology Muscle Journal Article Comparative Study

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Yunlong Wu, Yanhong Nong, Yanyan Zheng, Shi Fu, Jiayi Liu, Fei Ma, Ying Wang, XiaoJin Liu, Bin Ouyang, Qi Liu, Hai Huang, Zhiqiang Guo, Mei Wang. 2026-06-01. Comparative analysis of histological and transcriptomic characteristics in caudal muscles of nile crocodiles (Crocodylus niloticus), siamese crocodiles (Crocodylus siamensis), and their hybrids.. https://doi.org/10.1016/j.cbd.2026.101889

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Journal Article; Comparative Study resource Animals subject Comparative Study subject Gene Expression Profiling subject Journal Article subject Muscle, Skeletal subject

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