Loeschcke Volker, Krebs Robert A
Department of Ecology and Genetics, University of Aarhus, Ny Munkegade, 8000 Aarhus C, Denmark.
Evolution. 1996 Dec;50(6):2354-2359. doi: 10.1111/j.1558-5646.1996.tb03623.x.
Direct and correlated responses in selection for heat-shock resistance in adult and in larval Drosophila buzzatii were studied. Two lines were artificially selected for higher survival to heat stress as adults, and two other lines were reared under a fluctuating thermal environment as larvae, 35°C for 6 h and 25°C for 18 h, to "naturally" select for higher resistance as larvae. The latter two lines were duplicated after nine generations to yield additional lines to be "naturally" selected as larvae at a higher temperature, 38.2°C for 6 h. Control lines were maintained separately for the adult and larval selection lines. A significant direct response to selection was found for the adult selection lines. However, larvae of these adult selection lines were no more heat resistant than were larvae of the control lines. One of the two larval selection lines increased significantly in heat resistance as larvae. However, adult heat resistance was similar for lines selected as larvae and the corresponding control lines maintained at 25°C. Changes in developmental time accompanied changes in survival after stress in both sets of lines selected for increased heat resistance.
研究了在成年和幼虫期的布氏果蝇中，针对热休克抗性选择的直接和相关反应。对两条品系进行人工选择，使其成年后对热应激具有更高的存活率，另外两条品系在波动的热环境中作为幼虫饲养，即35°C持续6小时和25°C持续18小时，以“自然”选择出幼虫期具有更高抗性的品系。后两条品系在九代后进行复制，以产生更多品系，在更高温度38.2°C下持续6小时进行幼虫期的“自然”选择。分别为成年和幼虫选择品系维持对照品系。在成年选择品系中发现了对选择的显著直接反应。然而，这些成年选择品系的幼虫并不比对照品系的幼虫更耐热。两个幼虫选择品系中的一个作为幼虫时耐热性显著提高。然而，作为幼虫选择的品系和在25°C下维持的相应对照品系的成年耐热性相似。在两组选择提高耐热性的品系中，发育时间的变化伴随着应激后存活率的变化。
