Aging-TCA: a cross-species single-cell transcriptomic atlas for studying testicular aging.

The testis, with the highest number of transcriptionally active genes among human tissues, offers a unique window into how aging affects complex gene regulation. Recent advancements in single-cell RNA sequencing have enabled multi-species studies of aging-related transcriptome changes in testes. However, a comprehensive aging-related cross-species platform for analyzing testicular single-cell transcriptomes remains absent. To address this gap, we developed Aging-TCA (Aging-related Testicular Cell Atlas, available at http://tca.xielab.tech/)— a comprehensive online platform containing aging-related testicular single cell and spatial transcriptome profiles from human, cynomolgus monkey, mouse, and zebrafish across 89 samples and over 460, 000 testicular cells, nuclei or spots. Aging-TCA provides versatile tools for temporal and spatial analyzing testicular aging, including aging-related testicular gene expression visualization, cell-cell communication comparisons, cell-trajectory analysis, gene regulatory network analysis, testicular cell type auto-identification, time-series analysis, and spatial transcriptome comparisons. In summary, we provide a novel platform Aging-TCA for advancing cross-species research into testicular aging, facilitating future investigations in this field.