Conspicuous coloration in animals serves many functions such as anti-predation.Anti-predation strategies include motion dazzle and flash behavior.Motion dazzle markings can reduce the probability of being preyed on be...Conspicuous coloration in animals serves many functions such as anti-predation.Anti-predation strategies include motion dazzle and flash behavior.Motion dazzle markings can reduce the probability of being preyed on because the predators misjudge their movement.In flash behavior,prey demonstrate conspicuous cue while fleeing;the predators follow them;however,the prey hide their markings and the predators assume that the prey has vanished.To investigate whether bovids use conspicuous hindquarter markings as an anti-predatory behavior,we undertook phylogenetically controlled analyses to explore under what physiological characteristics and environmental factors bovids might have this color pattern.The results suggested that rump patches and tail markings were more prevalent in bovids living in larger-sized groups,which supports the hypothesis of intraspecific communication.Moreover,we observed the occurrence of conspicuous white hindquarter markings in bovids having smaller body size and living in larger groups,suggesting a motion dazzle function.However,the feature of facultative exposing color patterns(flash markings)was not associated with body size,which was inconsistent with predictions and implied that bovids may not adopt this as an anti-predator strategy.It was concluded that species in bovids with conspicuous white hindquarter markings adopt motion dazzle as an anti-predation strategy while fleeing and escaping from being prey on.展开更多
Nocistatin was synthesized by the solid-phase peptide synthesis method. Its effects on rat systemic arterial pressure; rat hindquarter vascular bed resistance; tension of rabbit pectoral, abdominal, femoral aorta musc...Nocistatin was synthesized by the solid-phase peptide synthesis method. Its effects on rat systemic arterial pressure; rat hindquarter vascular bed resistance; tension of rabbit pectoral, abdominal, femoral aorta muscle strips without endothelium; and nociceptin induced decreases of rat systemic arterial pressure were determined. The results showed that nocistatin can increase the systemic arterial pressure, increase the hindquarter vascular bed resistance and induce the contraction significantly of abdominal, femoral aorta muscle strips without endotheiium; it has no significant effect on tension of pectoral aorta muscle strips, it cannot antagonize significantly the decrease of rat systemic arterial pressure induced by nociceptin. These results suggest that nocistatin has some important effects on blood vessel activities.展开更多
基金This study received support from the Tibet Major Science and Technology Project(XZ201901-GA-06).
文摘Conspicuous coloration in animals serves many functions such as anti-predation.Anti-predation strategies include motion dazzle and flash behavior.Motion dazzle markings can reduce the probability of being preyed on because the predators misjudge their movement.In flash behavior,prey demonstrate conspicuous cue while fleeing;the predators follow them;however,the prey hide their markings and the predators assume that the prey has vanished.To investigate whether bovids use conspicuous hindquarter markings as an anti-predatory behavior,we undertook phylogenetically controlled analyses to explore under what physiological characteristics and environmental factors bovids might have this color pattern.The results suggested that rump patches and tail markings were more prevalent in bovids living in larger-sized groups,which supports the hypothesis of intraspecific communication.Moreover,we observed the occurrence of conspicuous white hindquarter markings in bovids having smaller body size and living in larger groups,suggesting a motion dazzle function.However,the feature of facultative exposing color patterns(flash markings)was not associated with body size,which was inconsistent with predictions and implied that bovids may not adopt this as an anti-predator strategy.It was concluded that species in bovids with conspicuous white hindquarter markings adopt motion dazzle as an anti-predation strategy while fleeing and escaping from being prey on.
基金the National NaturalScience Foundation of China (Grant No. 29972016) and the Natural Science Foundation of Gansu Province (Grant No. ZS 991-A23-056).
文摘Nocistatin was synthesized by the solid-phase peptide synthesis method. Its effects on rat systemic arterial pressure; rat hindquarter vascular bed resistance; tension of rabbit pectoral, abdominal, femoral aorta muscle strips without endothelium; and nociceptin induced decreases of rat systemic arterial pressure were determined. The results showed that nocistatin can increase the systemic arterial pressure, increase the hindquarter vascular bed resistance and induce the contraction significantly of abdominal, femoral aorta muscle strips without endotheiium; it has no significant effect on tension of pectoral aorta muscle strips, it cannot antagonize significantly the decrease of rat systemic arterial pressure induced by nociceptin. These results suggest that nocistatin has some important effects on blood vessel activities.
