Genome-wide identification and expression analysis of Wnt gene family in the forest musk deer (Moschus berezovskii) under musk secretion stage

The Wnt signaling pathway is ubiquitous in animals, playing a crucial role in embryonic development and adult tissue homeostasis in multicellular organisms. Wnt proteins act as ligands in this pathway, and their gene family encodes secreted signaling proteins involved in regulating vital physiological processes such as cell proliferation, migration, differentiation, polarity establishment, and maintenance. Based on the third-generation genome of the forest musk deer (FMD, Moschus berezovskii), this study aimed to identify members of the Wnt gene family, elucidate their physicochemical properties, analyze their chromosomal localization and gene structure, construct a systematic evolutionary tree, and predict the two-dimensional and three-dimensional structures of the Wnt protein family. Genome-wide identification was performed using BLASTP searches. Phylogenetic relationships were reconstructed using the Maximum Likelihood method, and 3D structures were predicted using SWISS-MODEL. Results revealed 18 Wnt (MbWnt) gene family members distributed across 8 chromosomes, with cDNA lengths ranging from 819 to 1900 base pairs in the FMD. The number of amino acids in the Wnt family proteins of the FMD ranged from 349 to 586aa, with isoelectric points (pI) between 7.96 and 10.24, and molecular weights concentrated between 30 and 62 kilodaltons. Signal peptide analysis showed that only MbWnt1, MbWnt2, MbWnt4, MbWnt6, and MbWnt9b contained signal peptides. Subcellular localization analysis indicated that the Wnt gene family is primarily located in the nucleus and cytoplasm. MbWnt proteins shared six conserved motifs. Phylogenetic analysis demonstrated high consistency in Wnt conservation and grouping in the genomes of cattle (Bos taurus), goat (Capra hircus), sheep (Ovis aries), and red deer (Cervus elaphus). Genome collinearity analysis demonstrated substantial chromosomal correspondence and orthologous conservation between the FMD and the three species of Bovinae and Ce. elaphus. The level of chromosome homology is relatively low, but the level of genome homology is relatively high among these species. Musk gland transcriptomic datasets indicated that the expression of MbWnt genes were stage-specific at musk secretion stage and non-secretory stage. RT-qPCR analysis indicated that six MbWnt genes were significantly highly expressed during the musk secretion stage, whereas two genes showed no significant differential expression.