Calcium binding tyrosine phosphorylation regulated protein (CABYR) has been implicated in sperm physiological function in several in vitro studies. It has also been implicated as a potential cause and diagnostic tool in asthenozoospermic human males. CABYR is known to be localized to the fibrous sheath, an accessory structure in the flagellar principal piece. Utilizing the CRISPR/Cas9 technology, we have knocked out this gene in mice to understand its role in male fertility. Cabyr KO male mice showed severe subfertility with a defect in sperm motility as well as a significant disorganisation in the fibrous sheath. Further, abnormal configuration of doublet microtubules was observed in the Cabyr KO spermatozoa, suggesting that the fibrous sheath is important for the correct organization of the axoneme. Our results show that it is the role of CABYR in the formation of the fibrous sheath that is essential for male fertility.
- Received May 31, 2016.
- Accepted October 13, 2016.
- © 2016. Published by The Company of Biologists Ltd