Osteoarthritis Affects Mammalian Oogenesis: Effects of Collagenase-Induced Osteoarthritis on Oocyte Cytoskeleton in a Mouse Model

Figure 4

Fluorescent imaging of meiotic spindles (FITC-labelled tubulin), chromatin (stained by Hoechst 3325), and actin structures (Phalloidin-TRITC) in control and CIOA oocytes. Original magnification 1000x. Bar = 10 μm. (a) An M I control oocyte with a normal spindle (green): A1, combined image with the aligned chromosomes (blue); A2, with the actin cap (red). A1 and A2 are epifluorescent images. The inset is an LSCM image of the same spindle used for measurement (25 μm long and 15 μm wide, pole widths 5 μm and 4 μm). (b) An M II control oocyte: B1, epifluorescence of a normal M II meiotic spindle in green, with the aligned chromosomes (blue); B2, the spindle and its actin cap adjacent (red), the polar body is seen too, by epifluorescence. The inset shows an LSCM image of the same spindle used for measurement (23 μm long and 14 μm wide, pole widths 3 μm and 6 μm). (c) An M I CIOA oocyte: C1, the spindle (green) is large (long and wide) with broad poles and disorganized microtubules around the spindle and its poles, and chromosomes (blue) are well aligned, by epifluorescence; C2, the same spindle combined with actin: a large ring (red) is seen instead of actin cap, by epifluorescence. Spindle size calculated using LSCM data: 45 μm long and 31 μm wide; poles: 14 μm and 12 μm. The inset shows a different M I CIOA spindle of normal length but wide shape and broad poles, with disorganized fibers. LSCM image measurements: 30 μm long and 19 μm wide; poles: 9 μm each. (d) An M II CIOA oocyte. D1, the spindle (green) is large (long and wide), its poles are broad and with disorganized microtubules, and the chromosomes (blue) are well aligned, by epifluorescence. D2, the same spindle with an actin ring (red) instead of the cap (the additional right inset shows the whole oocyte with its polar body at original magnification 400x), by epifluorescence. The LSCM image inset shows the measurements of the spindle (39 μm long and 21 μm wide; poles: 10 μm and 10 μm).

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