From spermatogenesis to sperm function: bioinformatics and experimental insights into the role of TEKT genes in human...

Infertility is a major global health concern, with male factors accounting for nearly half of all cases. While tektin proteins are known to stabilize flagellar microtubules, comprehensive validations of the TEKT gene family across diverse human infertility phenotypes remain limited. This study aimed to evaluate the expression and regulatory genetics of the TEKT family, particularly TEKT2, to determine its specific role in human spermatogenesis and sperm morphological disorders.

We analyzed public human RNA-seq and microarray datasets to evaluate TEKT expression in non-obstructive azoospermia (NoA; n = 41 cases, 33 controls), teratozoospermia (n = 8 cases, 13 controls), and asthenozoospermia (n = 8 cases, 10 controls). Transcriptomics revealed TEKT2 was significantly and consistently downregulated in NoA and teratozoospermia, but not in asthenozoospermia. We validated these in silico findings via Western blotting on human NoA testicular tissues and teratozoospermia spermatozoal samples (n = 30 clinical cases, 30 controls), confirming significantly reduced TEKT2 protein levels. To investigate the underlying etiology, targeted Sanger sequencing of the TEKT2 regulatory region was performed, which identified no pathogenic variants in the patient cohorts.

TEKT2 is structurally and developmentally essential for complete human spermatogenesis and proper sperm flagella formation. Crucially, the definitive absence of disease-causing regulatory mutations provides new evidence that TEKT2 downregulation in NoA and teratozoospermia is likely driven by alternative mechanisms, such as epigenetic modifications or post-transcriptional silencing. This finding actively redirects future therapeutic and diagnostic research toward these novel regulatory pathways.