TUBD1 (tubulin delta 1) is a noncanonical tubulin protein that functions as a structural component of specialized microtubule assemblies and regulates cytoskeletal organization. In mammalian spermatogenesis, TUBD1 stabilizes kinetochores during meiosis, enables proper spindle polarity and cytokinesis, and cooperates with microtubule-severing enzymes to regulate manchette remodeling and sperm head morphogenesis 1. Conditional knockout mice lacking TUBD1 exhibit male sterility, demonstrating its critical role in fertility 1. Beyond reproduction, TUBD1 participates in centriole-to-centrosome conversion by maintaining centriole microtubule integrity alongside CEP44, POC1B, and TUBE1 2. Alternative splicing of TUBD1 represents a clinically relevant mechanism in disease pathogenesis. Specific TUBD1 isoform expression profiles in peripheral blood associate with non-proliferative diabetic retinopathy risk (OR 8.1; p=0.039), with HIF-1 identified as a direct transcriptional regulator 3. TUBD1 splicing is regulated by angulin proteins ILDR1 and ILDR2 through binding to splicing factors TRA2A, TRA2B, and SRSF1 4, and by the oncogenic factor SRSF1 in lung cancer contexts 5. Circular TUBD1 (circTUBD1) functions as a miR-146a-5p sponge modulating TLR4 pathway signaling and pro-inflammatory responses in hepatic stellate cells 6. Genome-wide association studies implicate TUBD1 variants in metabolic syndrome susceptibility 7 and ovarian cancer PARP inhibitor resistance 8.