Specifically, Cyp26b1, encoding an RA degradation enzyme, Zbtb16, an undifferentiated spermatogonia marker gene, and Smcp (Sperm mitochondria-associated cysteine-rich protein), its loss causing asthenozoospermia [48], all lost their rhythmicity in the desynchronization group (Fig. 7i–k), implicating that circadian desynchronization likely leads to dysregulated RA signaling and defects in spermatogenesis and fertilization in mice. Here, ZBTB16 is linked to Reduced sperm motility.