Hyperthermia enhances methyl methanesulfonate-induced adaptive response in meiotic cells of grasshopper Poecilocerus pictus

To understand the role of hyperthermia (HT) in adaptive response, methyl methanesulfonate (MMS) adapted meiotic cells of Poecilocerus pictus were used. Poecilocerus pictus were treated with conditioning (L) or challenging (H) dose of MMS and 2-h time lag (TL) between these doses (L-2h-H) (combined) was employed. Different treatment schedules were used to analyse the influence of HT on MMS-induced adaptive response namely pre; inter; post-treatment and cross-adaptation. After each treatment schedules, chromosomal anomalies were analysed. The frequencies of chromosomal anomalies induced by conditioning and challenging doses of MMS were significantly higher (P < 0.0001) compared to that of the control or HT groups. The combined treatments resulted in significant reduction of chromosomal anomalies compared to additive effect of MMS (P < 0.0001). The pre, inter, post and cross-adaptation treatments with HT reduced the frequencies of chromosomal anomalies compared to the challenge and combined treatments with MMS. There is a protection against MMS-induced chromosomal anomalies by HT in in vivo P.pictus. This is the first report to demonstrate that HT enhances the MMS-induced adaptive response in in vivo meiotic cells.