Delta (δ-) and epsilon (ε-) tubulin are lesser-known cousins of alpha (α-) and beta (β-) tubulin. They are likely to regulate centriole function in a broad range of species; however, their in vivo role and mechanism of action in mammals remain mysterious. In unicellular species and mammalian cell lines, mutations in δ- and ε-tubulin cause centriole destabilization and atypical mitosis and, in the most severe cases, cell death. Beyond the centriole, δ- and ε-tubulin localize to the manchette during murine spermatogenesis and interact with katanin-like 2 (KATNAL2), a protein with microtubule (MT)-severing properties, indicative of novel non-centriolar functions. Herein we summarize the current knowledge surrounding δ- and ε-tubulin, identify pathways for future research, and highlight how and why spermatogenesis and embryogenesis are ideal systems to define δ- and ε-tubulin function in vivo.

Delta (δ-) 和 epsilon (ε-) 微管蛋白是 alpha (α-) 和 beta (β-) 微管蛋白的鲜为人知的表亲。它们可能在广泛的物种中调节中心粒功能；然而，它们的体内在哺乳动物中的作用和作用机制仍然是个谜。在单细胞物种和哺乳动物细胞系中，δ-和 ε-微管蛋白的突变会导致中心粒不稳定和非典型有丝分裂，在最严重的情况下会导致细胞死亡。除了中心粒，δ- 和 ε-微管蛋白在小鼠精子发生过程中定位于 manchette 并与 katanin-like 2 (KATNAL2) 相互作用，这是一种具有微管 (MT) 切断特性的蛋白质，表明新的非中心粒功能。在此，我们总结了当前关于 δ- 和 ε- 微管蛋白的知识，确定了未来研究的途径，并强调了精子发生和胚胎发生如何以及为什么是在体内定义 δ- 和 ε- 微管蛋白功能的理想系统。