SPAG8: Sperm Associated Antigen 8
A testis-specific protein involved in spermatogenesis and male fertility
Gene Information Card
| Symbol | SPAG8 |
|---|---|
| Full Name | Sperm Associated Antigen 8 |
| Gene Type | protein-coding |
| Chromosomal Location | 9p13.3 |
| NCBI Gene ID | 26227 ncbi.nlm.nih.gov/gene/26227 |
| Ensembl ID | ENSG00000136869 |
| UniProt ID | O76076 |
| OMIM ID | 605726 |
| HGNC ID | 11215 |
| Aliases | BS-63, MFS1, SPAG-8 |
Description
SPAG8 (Sperm Associated Antigen 8) is a protein-coding gene located on chromosome 9p13.3. It encodes a testis-specific protein that is essential for spermatogenesis, particularly in the formation of the sperm flagellum and acrosome. The protein is localized to the sperm tail and is involved in sperm motility and fertilization. SPAG8 is also known as BS-63, MFS1, or SPAG-8.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Male infertility with oligoasthenoteratozoospermia | Defects in SPAG8 impair sperm flagellar assembly and motility, leading to reduced sperm count and abnormal morphology | ClinVar, OMIM |
| Spermatogenic failure | Loss-of-function mutations disrupt spermatogenesis, resulting in azoospermia or severe oligozoospermia | NCBI Gene, OMIM |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 45.2 | High |
| Fallopian tube | 0.8 | Low |
| Prostate | 0.5 | Low |
| Other tissues | <0.5 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Sperm cells | N/A | High expression in mature sperm |
| Testicular germ cells | N/A | Expressed in spermatocytes and spermatids |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | Missense | Rare | Loss of start codon, likely loss of function |
| c.325C>T (p.Arg109*) | Nonsense | Rare | Premature stop, loss of function |
| c.487G>A (p.Gly163Arg) | Missense | Rare | Potential structural disruption |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations lead to truncated or absent protein, impairing spermatogenesis.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
No dominant-negative mutations reported.
View complete mutation data：
Gene Ontology (GO)
| • protein binding (GO:0005515) | • cytoplasm (GO:0005737) |
| • cilium (GO:0005929) | • spermatogenesis (GO:0007283) |
| • flagellated sperm motility (GO:0030317) | • axoneme assembly (GO:0035082) |
Pathways
• Spermatogenesis
• Cilium assembly and flagellar motility
Protein Summary
SPAG8 encodes a 262-amino acid protein (UniProt O76076) that is predominantly expressed in the testis. The protein localizes to the sperm flagellum and is involved in axoneme assembly and sperm motility. It interacts with other sperm-associated proteins to facilitate proper flagellar function. Loss of SPAG8 function leads to male infertility due to defective spermatogenesis and impaired sperm motility.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SPAG8 Knockout HEK293 Cell Line | EDJ-KQ51169 | Human | 26206 | Details Get a Quote |
| SPAG8 Knockout HeLa Cell Line | EDJ-KQ55895 | Human | 26206 | Details Get a Quote |
| SPAG8 Knockout A-549 Cell Line | EDJ-KQ64385 | Human | 26206 | Details Get a Quote |
| SPAG8 Knockout HCT 116 Cell Line | EDJ-KQ72836 | Human | 26206 | Details Get a Quote |
