Male specific conserved LncRNA TSCL1 regulated target mRNA translation by interaction with PIWIL1 [Ribo-seq]

Long non-coding RNAs are known to play crucial roles in various physiological processes in mammals, yet their functions in spermatogenesis remain largely underexplored. Here, we have identified a distinct category of conserved haploid spermatids-associated long non-coding RNAs (cHS-LncRNAs) characterized by their sequence-based conservation, specific expression in the testis, and elevated expression levels in haploid spermatids. Among these, we found that the testis specific conserved LncRNA 1 (Tscl1) exhibits the highest expression in round spermatids. Deletion of Tscl1 in mice exhibits reduced sperm motility, disordered mitochondrial sheath structure, abnormal fatty acid metabolism, and results in male infertility. Mechanistically, Tscl1 directly interacts with PIWIL1 and HuR via its 5' end stem-loop structure and multiple AU-rich elements, respectively. This binding pattern promotes the formation of the PIWIL1/eIF3f/HuR/eIF4G3 supercomplex, regulating the translation efficiency of fatty acid metabolism-associated mRNAs within the chromatoid body. Furthermore, the region where TSCL1 interacts with PIWIL1 is significantly enriched with TSCL1 variants identified in patients with non-obstructive azoospermia (NOA) compared to those in the fertile controls (OR=5.992, P=0.020, NCase=1,338, NControl=2,664). Taken together, our findings elucidate the critical role of Tscl1 in regulating the translation efficiency of target mRNAs through its collaboration with PIWIL1 and HuR during spermiogenesis. Overall design: Ribo-seq in TSCL1_Lnc_KO and TSCL1_WT