Twisted Tail

Sperm swim a great distance, relative to their size, to reach an egg. To do so, they use a tail-like structure called a flagellum whose architecture includes structures called dynein arms. Deficiencies in dynein proteins, such as DNAH3, are linked to male infertility. Researchers investigated this using whole-exome sequencing to study the genomes of infertile men with malformed sperm. In four men, they identified variations in the DNAH3 gene that led to almost no DNAH3 protein in their sperm flagella. These flagella were deformed, as captured using scanning electron microscopy (pictured), compared to healthy sperm (left). Male mice lacking DNAH3 were also infertile. Both the infertile mice and men had reduced levels of proteins associated with dynein arms in their flagella and their infertility was rescued by directly injecting sperm into an egg. DNAH3 is, therefore, important in determining sperm flagella shape and this knowledge may aid diagnosis and genetic counselling for infertile men.

Written by Lux Fatimathas

Lux Fatimathas

Writer

Having pursued science through a career in research, communications and publishing, she is currently a writer and editor for a healthcare marketing agency and also juggles freelance science writing.

• Image from work by Xiang Wang, Gan Shen, Yihong Yang, Chuan Jiang and Tiechao Ruan, and colleagues
• Chongqing Key Laboratory of Human Embryo Engineering, Women & Children’s Hospital of Chongqing Medical University, Chongqing; Dept of Obstetrics/Gynecology, West China Second University Hospital, Sichuan University, Chengdu, China
• Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Published in eLife, November 2024