Fig. 3.

In situ hybridization experiments with the probe recognizing gelsolin transcript to whole mount chicken embryos at late stages. a–m Whole mount in situ hybridization. n Vibratome section. a Stage HH29 embryo. High GSN expression is observed in the eye (green long arrow), within the developing skin and in limbs mesenchyme (long blue arrow). The presence of staining within vesicles in the head region is due to the probe trapping. b Stage HH33 embryo. Note the high GSN expression level in the eye (green long arrow) and limbs mesenchyme (long blue arrow). c–e Stage HH36 embryo. There is a strong signal for gelsolin mRNA observed in nictitating membrane (green long arrows), at peripheries of scleral ossicles, in cochlea of ear (white long arrow) and feather buds (black arrowhead and e). d′, e′ Higher magnifications of d and e, respectively. f–n Photos of cut longitudinal prior to the in situ hybridization embryo at HH36-stage. f–h High GSN expression is observed in the olfactory bulb (long black arrow), the nasal conchae, eye muscles (blue arrowheads), the developing comb (white arrowhead) and meninges. Note a line-patterned staining within meninges (green arrowheads). i Stained presumptive inter-innervation of neck skeletal muscles (white short arrow). j There is a high GSN expression in dorsal root ganglia, spinal nerves and presumably nerves within iliotrochantericus muscle. Note absence of signal in the more distal branches of the spinal nerves (short green arrow). j′ Higher magnification of j. k Dorsal view of the atrial part of a heart, with strongly gelsolin mRNA-positive cells (short black arrows). l, m Note high GSN expression on the surface of proventriculus, gizzard, spleen, small intestine, and pancreas. n A vibratome section of intestine and pancreas shown in m. There is observed a strong signal for gelsolin mRNA within circular and longitudinal muscles of the intestine wall. cm circular muscle, cb cell bodies of neurons, drg dorsal root ganglia, giz gizzard, im iliotrochantericus muscle, in intestine, la left atrium, liv liver, lm longitudinal muscle, lun lung, mes mesonephros, nc nasal conchae, pan pancreas, pv pulmonary vein, pve proventriculus, ra right atrium, sco scleral ossicles, spl spleen, sn spinal nerve. Scale bar n 1,000 μm