### SPAG8 Gene Overview

**Gene Symbol:** SPAG8  
**Location:** Human chromosome 17, positional information can be acquired using genomic resources.

#### 1. Associated Genes
The SPAG8 gene has been identified to interact and associate with several other genes and proteins. While the provided summaries primarily highlighted ACT (activator of CREM in testis) and RANBP9, other notable associated genes include:

- **CREM (cAMP response element modulator):** Plays a critical role in spermatogenesis and gene transcription.
- **FHL5 (Four and a Half LIM Domains 5):** Coactivator involved in the transcriptional activation regulated by CREM isoform tau.
- **CDK1 (Cyclin-dependent kinase 1):** Important for cell cycle progression, particularly the transition from G2 to M phase.

#### 2. Age-related Details
While specific studies directly linking SPAG8 to aging or age-related diseases are limited, potential implications involve its role in spermatogenesis and fertility. 

- **Infertility:** Increasing age is often associated with decreased fertility due to lower sperm quality and quantity. Since SPAG8 is crucial for healthy sperm functions and spermatogenesis, age-related declines in its expression or functionality could contribute to age-related infertility.
- **Microtubule Dysfunction:** Microtubule formation and dynamics are critical in various processes linked to aging and age-related diseases, such as neurodegenerative diseases. Dysregulation of microtubule-associated proteins in older tissues may contribute to cellular senescence.

#### 3. Drug Interactions
Currently, there are no specific drugs or drug classes explicitly listed as interacting with the SPAG8 gene. However, research exploring anti-sperm antibodies and their role in immunologic infertility could implicate contraceptive agents targeting sperm functions (though not necessarily directly targeting SPAG8). Potentially related categories may include:

- **Immunosuppressants:** These may impact the immune response against sperm antigens, including interactions related to SPAG8.

#### 4. Pathways and Biological Processes
The SPAG8 gene is involved in several biological processes and pathways, including:

- **Spermatogenesis:** Critical role in the development and maturation of sperm cells.
- **Acrosome Reaction:** Involved in the process which enables sperm to penetrate the egg's outer layers during fertilization.
- **Microtubule Dynamics:** Plays a role in the formation and organization of microtubules, essential for cellular structures and functions, including motility in sperm.
- **Cell Cycle Regulation:** Influences the G2/M phase transition of the cell cycle, possibly by modulating CDK1 activity.
- **Protein-Protein Interactions:** Functions as a part of the larger interactome involved in cilia and flagella formation and function.

### Conclusion
The SPAG8 gene is significant in male fertility and spermatogenesis, with complex interactions that underlie its biological functionalities. Continued research is necessary to further elucidate its role in aging, related diseases, and potential therapeutic avenues for fertility treatments.