Table 1.

Sox2 and Ganf expression in rostral blastoderm isolates (RBIs) of normal transections

Stage
3a/b 3c 3d 4 4+
TypeBCBCBCBCB
Sox26/110/23/110/37/110/48/8--
%54.5027.2063.60100--
Ganf 7/110/102/130/96/91/86/103/83/3
%63.6015.4066.712.56037.5100
  • RBIs probed for Sox2 and Ganf expression. Type B transected at the rostralmost level of the streak, and Type C transected 125μ m rostral to the streak (approximately one node diameter). Isolates cultured on agar/albumen substrate. Central epiblast (CE) present in RBIs at stage 3a/b results in neuralised tissue. At stage 3c, CE is incorporated into extending streak and is excluded from RBIs. Loss of neural specification results in loss of Ganf expression. From stage 3d onwards, neural specification exclusion of CE from RBIs has no effect. Type C RBIs all exclude CE have no Ganf expression at stages 3a/b and 3c, while from stage 3d onwards neural specification has begun and type C RBIs are expected to express Ganf and Sox2 in increasing numbers, as specified tissue is included in the RBIs.