Contents

08 January 2021
Vol 371, Issue 6525

About The Cover

Cover image expansion

COVER A mouse sperm lacking glycylation swims in circles. Glycylation is a posttranslational modification of tubulin that is predominately found in cilia and flagella, where it contributes to coordinating axonemal dynein motors that power the flagellar beating. Lack of glycylation causes an abnormal flagellar beat and results in circular instead of straight sperm swimming. This in turn severely affects male fertility. See page eabd4914.
llustration: C. Bickel/Science