Constitutive and heat-shock induced expression of Hsp70 mRNA during chicken testicular development and regression

The constitutive and heat shock induced expression of Hsp70 mRNA was invest igated in normal adult chicken testis and in adult testis after testicular regression Induced by diethylstilbestrol (DES) treatment. In addition to th e canonical form of Hsp70 mRNA, we have detected transcripts with an extend ed 5 ' UTR and transcripts containing, in the 5 ' UTR, sequences of the 18S ribosomal RNA. Hsp70 was expressed in unstressed male gonads in adult and regressed testis, being the expression much lower in regressed testis. Upon heat shock at 44 degreesC or 46 degreesC, Hsp70 was highly induced in both tissues. However, when testicular seminiferous tubules were incubated at t he chicken internal temperature of 39 degreesC, no induction of Hsp70 was o bserved in mature testis, while the expression markedly increased in regres sed testis. Induction at 39 degreesC was completely inhibited in the presen ce of 6 mM aspirin. Aspirin in the range 3-10 mM decreases the expression o f Hsp70 in unstressed and stressed testicular cells, in striking contrast w ith the effect observed in other tissues as liver. These data suggest that the expression of Hsp70 is regulated in a specific manner in chicken testis and particularly in the male gonad undergoing regression. (C) 2001 Wiley-L iss, Inc.