斑马鱼热耐受性对温度驯化的响应及其性别差异

Gender differences in thermal tolerance of zebrafish in response to temperature acclimation

为了探究斑马鱼(Danio rerio)热耐受性对温度驯化的响应及其性别差异,将性成熟斑马鱼分别于适温(28℃)、低温(20℃)和高温(34℃)下驯化14 d,之后测定不同温度驯化下雌鱼和雄鱼的临界高温(critical thermal maxima,CTmax)、致死高温(lethal thermal maxima,LTmax)、临界低温(critical thermal minima,CTmin)、致死低温(lethal thermal minima,LTmin)等热耐受性参数.结果表明:驯化温度对雄鱼和雌鱼的所有热忍耐参数(CTmax、LTmax、CTmin和LTmin)均影响显著(P<0.05),并且驯化温度和性别对热耐受性参数的影响具有交互作用(P<0.05).适温(28℃)驯化下,雌鱼与雄鱼各个热忍耐参数相比无显著差异(P> 0.05);低温(20℃)驯化下雌鱼的耐高温能力强于雄鱼,而高温(34℃)驯化下雌鱼的耐低温能力弱于雄鱼.结果提示:繁殖适温下雌雄斑马鱼的热耐受性趋于一致,而非繁殖适温下二者的热耐受性出现分化.

To clarify gender differences in thermal tolerance of fish in response to temperature acclimation, the thermal tolerance parameters, such as critical thermal maxima (CTmax), lethal thermal maxima (LTmax), critical thermal minima (CTmin) and lethal thermal minima (LTmin), were measured in male and female zebrafish (Danio rerio) after two weeks of acclimation at pre ferential temperature (28 ℃), low temperature (20 ℃), and high temperature (34 ℃). Our results showed that acclimation temperature (AT) and its interactions with gender had significant effects on the thermal tolerance of zebrafish (P<0.05). No significant difference was found in thermal tolerance between females and males at 28 ℃ acclimation (P>0.05). Females were more resistant to high temperature than males at 20 ℃ acclimation, whereas they were less resis tant to low temperature than males at 34 ℃ acclimation. Those results indicated that the thermal tolerance of males and females was highly consistent at suitable reproductive temperature, but was significantly different at non-suitable reproductive temperatures.