SPAG16 Antibody / Sperm-associated antigen 16, 100 ug

SPAG16 antibody recognizes Sperm-associated antigen 16, a structural and regulatory protein essential for the function of motile cilia and sperm flagella. SPAG16 is a component of the central apparatus of the axoneme, where it contributes to the coordination of dynein-driven motility. The SPAG16 antibody is widely used in studies of ciliogenesis, flagellar motility, and reproductive biology, as well as in research on primary ciliary dyskinesia and male infertility.

SPAG16 is encoded by the SPAG16 gene on human chromosome 2q34. Two main isoforms are produced: SPAG16L (long form), expressed predominantly in the testis and required for sperm motility, and SPAG16S (short form), expressed in ciliated tissues such as the trachea and ependyma. The long isoform localizes to the axonemal central pair microtubule complex, while the short isoform resides in the nucleus where it regulates gene transcription during spermatogenesis. Both isoforms are evolutionarily conserved, reflecting a fundamental role in ciliary function across species.

Research employing the SPAG16 antibody has identified the protein as critical for maintaining the integrity of the central apparatus in motile cilia. Knockout or mutation of Spag16 in mouse models results in male infertility, impaired ciliary beating, and hydrocephalus due to defective cerebrospinal fluid flow. Western blot analysis typically detects bands ranging from 70�95 kDa, depending on isoform and tissue type. Immunofluorescence reveals localization along flagella and cilia, consistent with its axonemal function.

SPAG16 interacts with other axonemal proteins such as SPAG6, SPAG17, and components of the radial spoke complex, forming an essential molecular network for rhythmic ciliary movement. Its nuclear isoform (SPAG16S) regulates expression of genes required for sperm maturation and differentiation. NSJ Bioreagents supplies a validated SPAG16 antibody optimized for western blot, immunofluorescence, and immunohistochemistry, providing a reliable reagent for elucidating the molecular architecture of cilia and flagella, as well as mechanisms underlying ciliary disorders and reproductive defects.