c-Fos-related antigens in the central nervous system of an insect, Acheta domesticus

Fos-related antigens (Fra) were detected in the nuclei of neurones in young adult Acheta domesticus female crickets by immunohistochemical analysis, u sing an antibody that recognizes the amino-acid sequence 127-152 of c-Fos p rotein. Specificity of Fra immunoreactivity was confirmed by Western blot a nalysis of nuclear extracts from neural tissues. A major immunoreactive dou blet with an apparent molecular mass of 52,000/54,000 Da was detected in nu clear extracts. Immunostaining of the 52,000/54,000 Da doublet showed varia tions in intensity during the first 5 days following the imaginal molt. Sta ining was more intense between day 2 and day 4 when ecdysteroid titers were high. Expression of Fra was low in allatectomized (i.e., deprived of juven ile hormone and ecdysteroids) and ovariectomized (i.e., deprived of ecdyste roids) females as compared to control females. These results show the invol vement of hormone-regulated process in expression of Fra. The effect of noc iceptive stimulation on Fra expression was tested. Twenty minutes after rem oval of the ovipositor, a supplementary band with an apparent molecular mas s of 70,000 Da appeared in the nuclear extracts, then decreased and disappe ared totally after 45 min. Several other Fos-related antigens with differen t temporal patterns of expression were also detected. Arch. Insect Biochem. Physiol. 45:139-148, 2000. (C) 2001 Wiley-Liss, Inc.