Heterochromatic Threads Connect Oscillating Chromosomes during Prometaphase I in Drosophila Oocytes
Figure 8
Incenp and Aurora-B localization is enriched between separated homologs and appears to localize to DAPI threads.
(A) A partial-stack projection of an X/X oocyte stained with DAPI (blue) and anti-Incenp antibody (green). Note the colocalization of both signals on the clearly visible 4 thread. (B) A partial-stack projection of an X/X oocyte stained with DAPI, anti-Incenp (green) and anti-Tubulin (red) antibodies. Even though there is no thread visible in DAPI staining, an Incenp thread appears to run between the separated 4th chromosomes (left arrow). The region of the spindle where the thread would run between separated 4th chromosomes also has the most intense tubulin staining. Furthermore, there appears to be an Incenp thread running between the heterochromatin of the two X chromosomes (right arrow). While these are normal sequence X chromosomes, it cannot be determined if they recombined or were spontaneously achiasmate and have already congressed to the main DNA mass. (C) A partial stack projection of an FM7/X oocyte stained with DAPI (blue) and anti-Incenp antibody (green). Note the two parallel lines of anti-Incenp staining, running between the 4 and X homologs. No DAPI threads are visible, although the 4th chromosomes have small hooks near where the Incenp thread appears. (D) A partial stack projection of an X/X oocyte stained with DAPI (blue) and anti-Aurora-B antibody (green). Note the small DAPI thread on the upper 4th chromosome (arrow) that co-localizes with the Aurora-B staining (arrows).