Antiparallel bundles of developing spermatid cells in Tribolium (Red Flour Beetle). In spermatids, the centriolar protein, Ana1, labels two foci (pink), the centriole, and the Proximal Centriole Like structure (PCL). The PCL is an atypical centriolar structure that lacks microtubules but contains centriolar proteins. The identification of the PCL in Tribolium demonstrates that the atypical centrioles are conserved, although the precise structures can be diverse. Nuclei are shown using Hoechst (blue) and acetylated tubulin (green) labels the axoneme (cilium). The image is credited to Emily Fishman, University of Toledo, and is described in the article “Atypical Centrioles are Present in Tribolium Sperm” published in Open Biology. http://rsob.royalsocietypublishing.org/content/7/3/160334.