SPAG4, Official Symbol SPAG4provided by HGNC Official Full Name sperm associated antigen 4provided by HGNC Primary source HGNC:HGNC:11214 See related Ensembl:ENSG00000061656 MIM:603038; AllianceGenome:HGNC:11214 Gene type protein coding RefSeq status REVIEWED Organism Homo sapiens Lineage Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo Also known as SUN4; CT127 Summary The mammalian sperm flagellum contains two cytoskeletal structures associated with the axoneme: the outer dense fibers surrounding the axoneme in the midpiece and principal piece and the fibrous sheath surrounding the outer dense fibers in the principal piece of the tail. Defects in these structures are associated with abnormal tail morphology, reduced sperm motility, and infertility. In the rat, the protein encoded by this gene associates with an outer dense fiber protein via a leucine zipper motif and localizes to the microtubules of the manchette and axoneme during sperm tail development. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Dec 2015] Expression Broad expression in testis (RPKM 8.6), pancreas (RPKM 6.3) and 20 other tissues See more Orthologs mouse all