The Effects Of Natural Enemies Odor On Behavior And C-fos MRNA Expression In Hypothalamus Of Anourosorex Squamipes

Anourosorex squamipes,which belongs to Soricomorpha,Soricidae of small mammal.Anourosorex squamipes has a large population,which is mainly distributed in the low mountain basin of Sichuan,and is one of the main farmland vermin in this area.Related studies have shown that the main communication mode of insectivores is olfactory communication,which is both accurate and complex and has become a hot spot of current research,and the research on the olfactory communication and the identification of natural enemies in Anourosorex squamipes is still blank.In this paper,the Anourosorex squamipes captured in the wild were used as research objects.The analysis of the behavioral responses of the Anourosorex squamipes and the different expression of c-fos m RNA in hypothalamus under the different species odor(distilled water,rabbit,cat,snake)can make it clear that whether the Anourosorex squamipes captured in the wild can identify different natural and non-natural enemies,and reveal the stress response mechanism of Anourosorex squamipes to the odor of natural enemies.The main findings are as follows:(1)Anourosorex squamipes have significant anti-predation behaviors under predator odor(cat odor group,snake odor group),including significantly increased concealing behavior,avoidance behavior,sniffing behavior,vigilance behavior,and significant reduction of contact behavior and locomotion behavior.In all the anti-predation behaviors of the time allocation,the concealing behavior is the highest in the time distribution of anti-predation behavior.Among the other non-anti-predation behaviors(freezing behavior,grooming behavior,and climbing behavior),Anourosorex squamipes have little difference in each group.This result shows that Anourosorex squamipes can identify the odor of natural enemies,and has significantly increased anti-predatory behaviors under the influence of natural enemy odor.At the same time,when stimulated by the odor of natural enemies,the anti-predatory behavior strategies of female and male Anourosorex squamipes are consistent,and there is no gender difference.(2)Under the influence of natural enemies odor(cat odor,snake odor),the feeding frequency,feeding time and food intake of female and male Anourosorex squamipes were significantly reduced,and there were no significant difference between distilled water odor group and rabbit odor group.There were also no significant differences between the natural enemy groups.This indicates that when faced with the odor of natural enemies,Anourosorex squamipes will weigh the predation risk and foraging benefits,and adopt a strategy to reduce feeding behavior to cope with predation risk.In addition,there was no gender difference in feeding behavior between female and male Anourosorex squamipes when stimulated by natural enemy odor.(3)Compared with the non-natural enemy groups(distilled water,rabbit odor),the expression of c-fos m RNA in the hypothalamus of female and male Anourosorex squamipes were significantly increased under the stimulation of natural enemies odor.The expression of c-fos m RNA in the hypothalamus of the natural enemy snake odor group was significantly higher than that in the cat odor group,indicating that the Anourosorex squamipes can not only identify the scent of natural enemies,but also distinguish different predators.The odor of the sympatric predator(snake)causes more defensive reactions than the odor of the allopatric predator(cat).In addition,there was no gender difference in the expression of c-fos m RNA in the hypothalamus of female and male Anourosorex squamipes when stimulated by natural enemies.Comprehensive analysis showed that Anourosorex squamipes have significant anti-predation behaviors and neurological responses under the influence of natural enemies odor,indicating that Anourosorex squamipes can identify the odor of natural enemies and distinguish the odor of different natural enemies.