【目的】 本研究旨在通过检测西方蜜蜂Apis mellifera的β-N-乙酰己糖胺酶4基因（AmFdl）在工蜂不同组织和发育阶段中的表达谱，并解析其蛋白分子特征和保守功能域，为深入开展AmFdl的功能研究提供基础。【方法】 通过RT-PCR和琼脂糖凝胶电泳鉴定AmFdl在西方蜜蜂中表达；利用RT-qPCR检测AmFdl在西方蜜蜂不同组织和发育阶段的表达差异。通过生物学相关软件预测和分析AmFDL的理化性质、分子特征、保守基序和功能域，并构建系统进化树。【结果】 AmFdl在西方蜜蜂工蜂不同组织中差异表达，在咽下腺中的表达量最高，且显著高于脑、中肠、脂肪体、表皮和毒腺等组织（P < 0.05）。AmFdl在工蜂卵中的表达量最高，其表达量随幼虫日龄增高而逐渐降低；AmFdl在2日龄工蜂成虫中的表达水平最高，显著高于1日龄和6日龄（P < 0.05），其中在6日龄工蜂中的表达量最低。AmFDL编码717个氨基酸，分子量约为80.8 kD，平均亲水系数为﹣0.359，不含典型的信号肽。西方蜜蜂、东方蜜蜂Apis cerana、无刺蜂Frieseomelitta varia、熊蜂Bombus vosnesenskii和美洲东部熊蜂Bombus impatiens的FDL蛋白含有2个相同的结构，分别为GH20_HexA_HexB_like和Glycohydro_20b2，AmFDL还包含5个保守的序列。西方蜜蜂和东方蜜蜂的FDL蛋白在进化树上归为同一支。【结论】 AmFdl基因在西方蜜蜂工蜂的咽下腺和卵中特异性高量表达。AmFDL是一种亲水性的非跨膜蛋白，具有保守的基序和功能域。

 [Aim]  To investigate the expression profile of the β-N-acetylhexosaminidase 4 gene (AmFdl) in different tissues and developmental stages of Apis mellifera workers, and to characterize the molecular properties and conserved domains of its encoded protein, thereby providing a foundation for the further functional investigation of this gene. [Methods]  The transcription of AmFdl was detected using RT-PCR followed by agarose gel electrophoresis, and its expression in various tissues and developmental stages was analyzed using RT-qPCR. The physicochemical properties, molecular features, conserved motifs and functional domains of AmFdl were predicted and analyzed using appropriate software, after which a phylogenetic tree was constructed. [Results]  AmFdl was differentially expressed in different tissues. Highest expression was in the hypopharyngeal glands, which was significantly higher (P < 0.05) than that in the brain, midgut, fat body, cuticle and venom glands. With respect to eggs and larvae, expression was highest in worker bee eggs, and thereafter gradually decreased with larval age. With respect to worker bees, expression was highest in 2-day-old workers, significantly higher (P < 0.05) than that in 1-day-old or 6-day-old workers, and lowest in 6-day-old workers. AmFdl encodes 717 amino acids, has a molecular weight of about 80.8 kD, an average hydropathy index of ﹣0.359, and does not contain a typical signal peptide. The FDL proteins of the Apis mellifera, Apis cerana, Frieseomelitta varia, Bombus vosnesenskii and Bombus impatiens, all contain the same two structural domains, GH20_HexA_HexB_like and Glycohydro_20b2, and AmFdl also have five conserved motifs. The FDL proteins of Apis mellifera and Apis cerana cluster together on the evolutionary tree. [Conclusion]  The AmFdl gene is predominantly expressed in the hypopharyngeal glands and eggs of Apis mellifera workers. AmFdl is a hydrophilic, non-transmembrane protein with conserved motifs and functional domains.