Identification of candidate genes responsible for innate fear behavior in the chicken.

Identifying the genes responsible for quantitative traits remains a major challenge. We previously found a major QTL on chromosome 4 affecting several innate fear behavioral traits obtained by an open-field test in an F2 population between White Leghorn and Nagoya breeds of chickens (Gallus gallus). Here, an integrated approach of transcriptome, haplotype frequency, and association analyses was used to identify candidate genes for the QTL in phenotypically extreme individuals selected from the same segregating F2 population as that used in the initial QTL analysis. QTL mapping for the first principal component, which summarizes the variances of all affected behavioral traits in the F2 population, revealed the behavioral QTL located at 14-35 Mb on chromosome 4 with 333 genes. After RNA-seq analysis using two pooled RNAs from extreme F2 individuals, real-time qPCR analysis in the two parental breeds and their F1 individuals greatly reduced the number of candidate genes in the QTL interval from 333 to 16 genes. Haplotype frequency analysis in the two extreme F2 groups further reduced the number of candidate genes from 16 to 11. After comparing gene expression in the two extreme groups, a conditional correlation analysis of diplotypes between gene expression and phenotype of extreme individuals revealed that NPY5R and LOC101749214 genes were strong candidate genes for innate fear behavior. This study illustrates how the integrated approach can identify candidate genes more rapidly than fine mapping of the initial QTL interval and provides new information for studying the genetic basis of innate fear behavior in chickens.

Male and female mice display consistent lifelong ability to address potential life-threatening cues using different post-threat coping strategies.

BACKGROUND: Sex differences ranging from physiological functions to pathological disorders are developmentally hard-wired in a broad range of animals, from invertebrates to humans. These differences ensure that animals can display appropriate behaviors under a variety of circumstances, such as aggression, hunting, sleep, mating, and parental care, which are often thought to be important in the acquisition of resources, including territory, food, and mates. Although there are reports of an absence of sexual dimorphism in the context of innate fear, the question of whether there is sexual dimorphism of innate defensive behavior is still an open question. Therefore, an in-depth investigation to determine whether there are sex differences in developmentally hard-wired innate defensive behaviors in life-threatening circumstances is warranted. RESULTS: We found that innate defensive behavioral responses to potentially life-threatening stimuli between males and females were indistinguishable over their lifespan. However, by using 3 dimensional (3D)-motion learning framework analysis, we found that males and females showed different behavioral patterns after escaping to the refuge. Specifically, the defensive "freezing" occurred primarily in males, whereas females were more likely to return directly to exploration. Moreover, there were also no estrous phase differences in innate defensive behavioral responses after looming stimuli. CONCLUSIONS: Our results demonstrate that visually-evoked innate fear behavior is highly conserved throughout the lifespan in both males and females, while specific post-threat coping strategies depend on sex. These findings indicate that innate fear behavior is essential to both sexes and as such, there are no evolutionary-driven sex differences in defensive ability.

The Impact of Noise Anxiety on Behavior and Welfare of Horses from UK and US Owner's Perspective.

Noise anxiety is an over-reaction to loud noises commonly detected among pets and can greatly impact on their welfare and on their management. When exposed to noisy events, horses can show intense escape attempts, which may cause severe accidents for the horse and the rider/handler. The aim of the present study was to investigate, through a web survey, UK and US owners' perception of noise anxiety severity in their horses, their management strategies and perceived efficacy. The questionnaire was shared via social networking and advertised as "What is your horse afraid of?". Over a total of 1836 questionnaires filled out; 409 owners reported that their horse has shown unusual behavior during a noise event. A two-step cluster analysis identified two groups: very anxious (VA) and slightly anxious (SA). VA horses were reported to have higher frequency of anxiety behaviors; higher frequency of signs of noise reactivity; and their anxiety did not improve with time. The most used management strategies consisted in providing hay throughout the night, turning in/out their horse or moving it to a paddock. A binomial logistic regression identified that horses that have reported injuries during noise events were more likely to be clustered as VA (OR = 0.24, 95% CI: 0.08-0.76); while providing hay throughout the night was more likely to be very effective management strategy in SA horses (OR = 0.41, 95% CI: 0.16-1.01). Our results confirmed that noise anxiety is a growing behavioral problem that can lead to important welfare concerns for horses. New management strategies, including the use of medicinal products, should be considered to reduce behavioral and physiological signs and help horses to cope with noisy events.

Identification and survival analysis of TTA/TETO-CCKR-2 double transgenic mice / 中国组织工程研究

BACKGROUND: The inducible forebrain-specific cholecystokinin receptor-2 (CCKR-2) double transgenic (tTA/tetO-CCKR-2 tg, abbreviated as dtg) mice are an ideal model of anxiety-related diseases. However, there is still a lack of model identification and life related data OBJECTIVE: To identify the genomic DNA of the offspring and the specific expression of CCKR-2 transgene in the forebrain, and to analyze the survival probability of dtg mice. METHODS: α-CaMKII/tTA single transgenic mice and tetO-CCKR-2 single transgenic mice were cross-fertilized to construct a dtg mouse model. The genomic DNA was extracted from the tail of the offspring, and the genotypes were detected by PCR and agarose gel electrophoresis. Wild-type (WT) mice were used as controls. In situ hybridization was used to detect the expression of CCKR-2. Survival of dtg mice and WT mice (30 females and 30 males) was observed and recorded within 2 years. The study protocol was approved by the Experimental Animal Ethics Committee of Southwest Medical University, with an approval No. 20150068. RESULTS AND CONCLUSION: Agarose gel electrophoresis results showed the molecular weight of the PCR products of dtg mice was consistent with the expected target gene fragment. In situ hybridization results showed a strong signal of CCKR-2 was detected in the forebrain of dtg mice, but hardly present in the WT mice. The median survival time of dtg mice was 76 weeks in females and 77 weeks in males. The survival probability was decreased with age in dtg mice. The survival probability of WT mice was significantly better than that of dtg mice (P < 0.001). There was no significant sex difference between males and females of dtg mice (P=0.577). Therefore, the specific expression of CCKR-2 transgene in the forebrain can be identified using PCR amplification, genomic DNA extraction, agarose gel electrophoresis, and in situ hybridization. tTA/tetO-CCKR-2 double transgenic induction may shorten the survival time of mice, but no significant difference is observed between the females and males of dtg mice.

Height Simulation in a Virtual Reality CAVE System: Validity of Fear Responses and Effects of an Immersion Manipulation.

Acrophobia is characterized by intense fear in height situations. Virtual reality (VR) can be used to trigger such phobic fear, and VR exposure therapy (VRET) has proven effective for treatment of phobias, although it remains important to further elucidate factors that modulate and mediate the fear responses triggered in VR. The present study assessed verbal and behavioral fear responses triggered by a height simulation in a 5-sided cave automatic virtual environment (CAVE) with visual and acoustic simulation and further investigated how fear responses are modulated by immersion, i.e., an additional wind simulation, and presence, i.e., the feeling to be present in the VE. Results revealed a high validity for the CAVE and VE in provoking height related self-reported fear and avoidance behavior in accordance with a trait measure of acrophobic fear. Increasing immersion significantly increased fear responses in high height anxious (HHA) participants, but did not affect presence. Nevertheless, presence was found to be an important predictor of fear responses. We conclude that a CAVE system can be used to elicit valid fear responses, which might be further enhanced by immersion manipulations independent from presence. These results may help to improve VRET efficacy and its transfer to real situations.

Effect of“Qiangzhizufang” on the rat model of Tourette syndrome combined with fear / 中国比较医学杂志

Objective To explore the functional mechanism of a Chinese medicine compound “Qiangzhizufang”on rat model of Tourette syndrome ( TS) combined with fear.Methods The rat model of TS combined with fear was established by intraperitoneal injection of 3,3’-iminodipropionitrile (IDPN) combined with acoustic stimulation.After giving different drug lavage treatment, the changes of behavior of the rat models were assessed by field test and behavior test.The content of DA, TH and TH mRNA in the brain tissue was detected by HPLC, immunohistochemistry and RT-PCR, separately.Results Compared with the normal control group, stereotyped behavior and exercise behavior were increased, freezing time prolonged, but the content of DA, TH and TH mRNA in the brain tissue were not obviously changed in the model control group.Compared with the model control group, the stereotyped behavior and exercise behavior were decreased, content of DA, TH and TH mRNA in the brain tissue was decreased in the “Qiangzhizufang” group. Conclusions The Chinese medicine compound“Qiangzhizufang” can improve the behavior in rat models of TS combined with fear.This effect may be realized through down-regurating TH mRNA expression, reducing the content of TH, and reducing the dopamine synthesis.