Fig. 1. A typical embryonic (18 days, brain tissue) HSP response (representing Lohmann, Hy Line and Bedouin fowl strains) under heat shock conditions (6 h at 42°C) that precede the deleterious effects on hatchability (N=6 in each treatment). (A) HSF–DNA-binding activity detected by EMSA. EMSA was performed with a [³²P]HSE oligonucleotide and whole brain tissue extracts. (B) Western blot analysis of HSP70 and HSP90. Each lane represents a different individual. C, control, unexposed individuals; HS, at the end of the heat exposure. A similar pattern was observed in 12-day-old embryos exposed to 43°C. (C) In vivo metabolic labelling analyzed by [³⁵S]methionine incorporation. T_a, ambient temperature; time (h), heat shock period in hours.