Odf1, also known as outer dense fiber of sperm tails 1 and HSPB10, is a major protein of the accessory fibres of the mammalian sperm tail [1,2]. It is crucial for male fertility as it is involved in sperm motility, the development of the flagellum, and the formation of the coupling apparatus that tightly links the sperm head and tail [1,2].

In gene-knockout mouse models, depletion of Odf1 by homologous recombination led to male infertility. Sperm tails were present in the epididymis, but no intact spermatozoa were found due to sperm decapitation, indicating Odf1 is essential for the head-tail linkage [1]. Haplo-deficiency of Odf1 in mouse sperm caused relaxation of the head-to-tail linkage and severe male subfertility, which may be a paradigm for unexplained infertility in humans [2]. Additionally, the interaction between Odf1 and other proteins like WDR64 is involved in the assembly of the manchette and flagella during spermiogenesis [3]. The poly(A) polymerase TENT5C regulates the spatial translation of Odf1 mRNAs during spermiogenesis, and its absence leads to headless spermatozoa and other flagellar abnormalities associated with Odf1 deficiency [4].

In conclusion, Odf1 is essential for sperm morphogenesis and male fertility, as demonstrated through gene-knockout mouse models. Its functions in sperm-related processes provide insights into male infertility, a disease area where Odf1-related research may help explain some idiopathic cases [1,2,4].