Increased hsp22 RNA levels in Drosophila lines genetically selected for increased longevity

RNAs for the small heat shock protein (hsp) genes hsp22 and hsp23 are induc ed during Drosophila aging, suggesting that these genes might have specific functions at late ages. To determine if hsp22 and hsp23 gene expression mi ght correlate with life span, RNA levels for these and additional genes wer e analyzed throughout the adult life span in a set of five outbred "O" line s, which have been genetically selected for increased longevity, and in fiv e matched control "B" lines. Control ribosomal protein genes rp49 and AP3/R pPO RNA levels were similar in O and B lines. In contrast, hsp22 RNA levels were twofold-tenfold higher in all five O lines relative to all five B lin es, while hsp23 exhibited a smaller but significant increase. Thus increase d hsp22 and hsp23 RNA levels correlate with the increased life span and inc reased stress resistance of the genetically selected O lines.