Spata21, also known as Spermatogenic cell-specific gene-3 in rats [4], may play diverse roles. Its rat counterpart Spergen-3 encodes a 75-kDa soluble protein with EF-hand motifs, proline-repeat, and a nuclear localization signal, and is specifically expressed in haploid spermatids, potentially involved in their differentiation [4].

In genetic studies, Spata21 has been associated with multiple conditions. In a whole-genome sequencing analysis of familial essential tremor, Spata21 was among the genes identified through aggregate variant non-parametric linkage analysis, suggesting its possible involvement in essential tremor aetiology through various pathways like the epidermal growth factor receptor-phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha-AKT serine/threonine kinase 1 (EGFR-PI3K-AKT) and Mitogen-activated protein Kinase 1 (ERK) pathways, Reactive oxygen species (ROS) and DNA repair, gamma-aminobutyric acid-ergic (GABAergic) system, and RNA binding and regulation of RNA processes [1]. In a gene-based association study of adolescent idiopathic scoliosis, Spata21 was found to be potentially associated with the susceptibility of the disease, indicating its role in this multifactorial disorder possibly involving central neural system development and bone formation pathways [3]. In a whole-exome sequencing of hepatocellular carcinoma, a non-synonymous somatic variant in Spata21 was uncovered, though further research on its role in carcinoma cell proliferation was focused more on PCK2 and HUWE1 [2].

In conclusion, Spata21 seems to have significant functions in spermatid differentiation and may be implicated in essential tremor, adolescent idiopathic scoliosis, and potentially hepatocellular carcinoma. These associations highlight the importance of studying Spata21 through genetic models to better understand the biological processes and disease mechanisms it is involved in [1,2,3,4].

References:

1. Clark, Lorraine N, Gao, Yizhe, Wang, Gao T, Rodriguez, Sandra M Barral, Louis, Elan D. 2022. Whole genome sequencing identifies candidate genes for familial essential tremor and reveals biological pathways implicated in essential tremor aetiology. In EBioMedicine, 85, 104290. doi:10.1016/j.ebiom.2022.104290. https://pubmed.ncbi.nlm.nih.gov/36183486/

2. Liu, Yan-Xuan, Zhang, Shu-Fang, Ji, Ying-Hua, Wang, Geng-Fu, Zhang, Guang-Wen. 2012. Whole-exome sequencing identifies mutated PCK2 and HUWE1 associated with carcinoma cell proliferation in a hepatocellular carcinoma patient. In Oncology letters, 4, 847-851. doi:. https://pubmed.ncbi.nlm.nih.gov/23205112/

3. Xu, Leilei, Huang, Shushu, Qin, Xiaodong, Qiu, Yong, Zhu, Zezhang. . Investigation of the 53 Markers in a DNA-Based Prognostic Test Revealing New Predisposition Genes for Adolescent Idiopathic Scoliosis. In Spine, 40, 1086-91. doi:10.1097/BRS.0000000000000900. https://pubmed.ncbi.nlm.nih.gov/25811265/

4. Iida, Hiroshi, Yamashita, Haruhiro, Doiguchi, Masamichi, Kaneko, Takane. . Molecular cloning of rat Spergen-3, a spermatogenic cell-specific gene-3, encoding a novel 75-kDa protein bearing EF-hand motifs. In Journal of andrology, 25, 885-92. doi:. https://pubmed.ncbi.nlm.nih.gov/15477360/