A rat testis-specific hsp70 gene-related transcript is coded by a novel gene from the hsp70 multigene family

To establish the identity of testis-specific hsp70 gene-related transcript, the expression pattern of the hsp70 gene family in testis and liver of rats subjected to whole body hyperthermia was investigated. In control liver two hsp70 gene-related transcripts of about 2.2 and 2.5 kb were detected. Increased body temperature resulted in high accumulation of 2.5 kb RNA and in the appearance of abundant amounts of another heat-induced transcript of approx. 2.7 kb. In testis of control rats only one hsp70 gene-related transcript has been identified and hyperthermia did not affect its level. This transcript migrated in 1% agarose-formaldehyde gel slightly faster than the 2.5 kb heat-induced RNA detected in liver and epididymis. The uniqueness of the testicular hsp70 gene-related transcript has been confirmed by its hybridization properties. At stringent conditions this transcript did not hybridize with a human hsp70 gene-related probe in contrast to the 2.5 and 2.7 kb heat-induced RNA species.