Effects of actomyosin contraction on early forebrain morphogenesis
(HH11–12). Stage HH11 embryos were cultured 6 h in media containing
blebbistatin or calyculin A to inhibit or enhance contractility, respectively
(control n=9, blebbistatin n=15, calyculin A n=12). (A–C)
Bright-field images reveal altered BT morphology under each condition (dorsal
view). White arrowheads indicate AIS, black arrowheads indicate the optic stalk
(OS), and white arrows highlight previously formed DMB. Dashed lines indicate
locations used to compute average radii for T (red), D (green) and M (blue).
Scale bars: 200 µm. (A’–C’)
Representative OCT cross sections of SP for each case. Dashed white lines
indicate locations used to compute average radii for the OS, and the average
radius of T was calculated considering lumen area between the optic stalks.
Scale bars: 100 µm. (A”–C”)
Representative AIS cross sections for each case. Scale bars: 100µm.
(D) Relative constrictions based on average radii at locations
indicated in (A–C), as well as relative OS stretch ratio
λOS based on locations indicated in
(A’–C’). *P<0.05, **P<0.001
(E) Representative sagittal cross sections before and after 6 h
in blebbistatin, followed by washout (n=6). White arrowheads indicate AIS. Scale
bars: 200 µm.