Figure 1.
![Figure 1. Longitudinal (top) and cross-sectional (bottom) images. (A) Mouse sperm with nine microtubule doublets surrounding a central pair (reproduced from Chung et al. [2014] with permission from Elsevier). (B) Ciliated (motile) cells (blue arrowhead) in a mouse respiratory tract with the characteristic nine doublets and central pair of microtubules (blue arrow; reproduced from Voronina et al. [2009] with permission from The Rockefeller University Press). (C) Primary cilium from a cell on a mouse limb bud. Note the absence of a central microtubule pair (reproduced from Moon et al. [2014] with permission from the National Academy of Sciences).](https://cdn.rupress.org/rup/content_public/journal/jgp/149/1/10.1085_jgp.201611696/5/jgp_201611696_fig1.jpeg?Expires=1773463689&Signature=ODAzMfvrpiAcfxczBP720sxNguPJF~OfDlhODm9H~N~RuaFxXQYZNHZlt5NFwc4s6h3rZfn82dDYuIzmf2AEF5vAFgJHQZZntJl~u~rob51wB8qGc~RDUhNBJlDsSLp4FqKGmiF~5~QvfV2LAg5pYQpXwVOm~KfIc2M7gS2CsL1vMMGljY9o9xK53a~ONCI5i~FRPZjYjbBT~VGMiirwN-6tA1lk5u42VsitqYGObzf44PeDNo5BiQc8wrKQ2~VdVFiI1sKmgf~uW3rNe7Q47bzcFe9EmpC6vr~m-vDEWTxJlJPeswZz4PjCIgv7V-QxFlYDBFtc1i0si-LtAnGRlg__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
Longitudinal (top) and cross-sectional (bottom) images. (A) Mouse sperm with nine microtubule doublets surrounding a central pair (reproduced from Chung et al. [2014] with permission from Elsevier). (B) Ciliated (motile) cells (blue arrowhead) in a mouse respiratory tract with the characteristic nine doublets and central pair of microtubules (blue arrow; reproduced from Voronina et al. [2009] with permission from The Rockefeller University Press). (C) Primary cilium from a cell on a mouse limb bud. Note the absence of a central microtubule pair (reproduced from Moon et al. [2014] with permission from the National Academy of Sciences).
