A) An ex vivo timelapse, monitoring SGPs (six4-nlsGFP) and all nuclei (HistoneRFP). At t=0, the pro-hub is just passed initial assembly, and covers an extended region (outline). Its nuclei are separated by negative space (white arrowheads). A GSC enters metaphase (t=30min, yellow arrow) and then anaphase (t=45min, arrow and arrowhead mark daughters), with division orthogonal to the hub-GSC interface. Coincident with anaphase, the hub cell nucleus (white arrow) nearest the dividing GSC, moves closer to its neighbor (compare internuclear distance at t=30 and 45min). By the end of the timelapse, the hub has compacted with less negative space among hub cell nuclei (t=4h 45min, outline). B) An in vivo timelapse of a gonad monitoring SGPs (six4-nlsGFP) and all nuclei (HistoneRFP). The initial panels show a stage just prior to and at assembly (t=2h 10min – 2h 40min). After assembly, a GSC divided orthogonal to the hub (t=4h 20min – 4h 30min, arrow; daughter cell marked by arrowhead). For A-B, scale bar is 10 microns. C, D) Quantification of mitotic germ cells by stage, comparing gonads imaged ex vivo (C) and in vivo (D). Compaction begins ~16h AEL, and is completed by ~23h AEL.