猪攻击行为的分子标记筛选

猪的攻击行为（如打斗、咬尾）具有遗传性，外种猪较我国地方猪的攻击性更强，导致了诸多动物福利问题，影响了养猪的生产效率。为了筛选出猪攻击行为的分子标记用于育种，研究将对500头苏淮猪（含75%大约克和25%淮猪血统）仔猪进行Backtest测试、咬尾测试，和混群前、后的行为和体表伤痕的评分，采样检测与攻击行为相关的生理生化指标：皮质醇、肾上腺素、血糖、雌二醇、睾酮和血清素等。同时采猪耳组织样提取基因组DNA，用PCR和DNA测序技术，对血清素、类固醇激素和多巴胺相关通路中攻击行为候选基因的启动子区、3’-UTR区、内含子和外显子边界的可变剪切区和可变串联重复序列（VNTR）的区域的遗传多态进行精细分析。最后结合Backtest测试、咬尾测试，混群前后的行为、伤痕和生理生化指标，分析筛选出影响猪攻击行为的生理生化分子标记和分子遗传标记位点或单倍型，为猪的行为性状育种提供分子标记。

Aggressive behaviors (such as fighting and tail biting) of pigs are hereditary. European pigs are more aggressive than Chinese local pigs, resulting in the many animal welfare issues that have seriously influenced the efficiency of European pig production. To screen the molecular markers of aggressive behavior in pigs, in this study we will perform Backtest and tail-chew test using 500 head of weaned Suhuai pigs (75% Yorkshire and 25% Huai pig), and record and analyze their behaviors and assess the lesions on the body and tail before and after mixing, and detect the physiological and biochemical indexes, such as cortisol, epinephrine, blood sugar, estradiol, testosterone, and serotonin. A fine analysis on genetic polymorphism of aggression candidate genes at promoter region, 3'-UTR regions, boundary between intron and exon and variable number tandem repeats (VNTR) using PCR and DNA sequencing. Then to screen the molecular markers or haplotypes for aggressive behavior by association with the results of Backtest, tail-chew test, behavioral analysis, lesions on the body and tail, and physiological and biochemical indexes. The research results will provide molecular markers for behavior trait in pig breeding.