The Study Of Social Behavior, Secretion Of Sex Hormone And AVP Gene Expression On Cricetulus Barabensis Under Predation Risk

Rodent outbreaking has huge threats to the agricultural production in China being a largeagricultural country. In recent years much highly toxic rat poison were used and theabundance were controlled in a short period of time, but inevitably causes serious ecologicaldamage to the environment. Striped hamster (Cricetulus barabensis) is one of the dominantrodent species in most farmland areas at North of China. Its large population caused greatdamage to agricultural production. In order to protecting the agricultural production, effectiveand ecological of controlling Cricetulus barabensis must be used.Rodents have been studied for a long time and the former studies focus on the behaviorand endocrine, particular on social behavior and hormone secretion. Social behavior is one ofthe basic content of animal behavioral ecology, including a series of activities after theencounter between individuals within populations and meet. The social behavior of animals isdominated by the nervous system, and inextricably linked with the endocrine system. In thisstudy, striped hamster （Cricetulus barabensis） as the experimental animal and the weaselurine as the source of predation risk, the social behavior, sex hormone content andhypothalamic arginine vasopression (AVP) gene expression levels were detected under naturalenemies’ odor. In the beginning, behavioral experiments were performed, to obtain thedifferences in social behavior of the experimental and control groups, and then the stripedhamster (Cricetulus barabensis) were executed to determinate the concentration of fecalhormone and AVP mRNA in the hypothalamus.The experimental results showed that the striped hamster social behavior was stronglyinfluenced by the weasel odor. Between the experimental and control groups, of maleinvestigating behavior frequency, chasing behavior frequency and the cumulative time ofinvestigating and chasing were extremely significant (P＜0.01); the differences of self-grooming frequency, attack frequency, attack cumulative time are significant(P＜0.05).Between the experimental and control groups, the differences of female investigatingbehavior frequency, self-grooming frequency, attack frequency, cumulative time of amicableinteraction, threats and attacks were extremely significant (P＜0.01); the differences ofinvestigating and self-grooming cumulative time were significant (P＜0.05).Compared with the control group, the determination of fecal testosterone and estradiollevels in experimental group was significantly inhibited by weasel odor. The analysis resultsof hypothalamic AVP mRNA expression levels showed that the weasel odor significantly inhibited the expression levels of AVP mRNA in the male Cricetulus barabensishypothalamus; but the female in the opposite.The correlation analysis showed highly significant positive correlation (P <0.01)between the male chasing and investigating behavior and testosterone concentration; thecorrelation between female investigating, self-grooming, aggressive behavior and estradiollevels were significant (P<0.05). The correlation between male chasing, investigatingbehavior and AVP mRNA levels are highly significant positive correlation (P<0.01); thecorrelation between female investigating, aggressive behavior and the expression of AVPmRNA amount are highly significant correlation (P<0.01). Exclude behavioral factors in thepartial correlation analysis showed that the correlation between male testosterone levels andAVP mRNA levels is highly significant (P<0.01) positive correlation; the relation betweenfemale estradiol levels and the expression of AVP mRNA is highly significant (P<0.01)negative correlation.These results showed that natural enemies’odor had a strong effect on the behavior,endocrine and genetic expression of Cricetulus barabensis, thus, the use of natural enemies’odor to control rodent will make good effectiveness. This study provide a reference to thestudy of rodents from the view of combining microscopic with macro, and it also showed anew way to the ecological rodenticides research and development, and it will also contributeto the mechanisms and functional analysis of Cricetulus barabensis under natural enemies.