拉布拉多犬神经类型早期鉴定的分子遗传标记体系的建立

The successful breeding and training of guide dogs is closely related to the canine genetic characteristics. The guide dog breeding is mainly depended on the temperament test. However, this method has shortcomings of uncertainty, subjectivity and low breeding efficiency. Thus, the successful training rate of the guide dogs is low (approximately 30%), the cost is high (15-20 million yuan per guide dog), and demand exceeds supply. Genetic related nerve patterns play an important role in determining the successful dog breeding, such as MAO, COMT and 5 - HT and dopaminergic system related genes have been proved to closely relate to nerve patterns. If we can find the genes related genetic molecular markers and using them to screen the guide dogs, the sucessful breeding rate of guide dogs will be improved significantly. In this project, by using our successful and unsuccessful training guide dog (Labrador Retriever) and the candidate gene method, we will detect single nucleotide and microsatellite polymorphism in the above selected genes and their linked DNA fragments to find the Labrador Retriever four nerve patterns related molecular genetic markers. By using the breeding puppies to validated and optimized the selected molecular genetic markers, we will finally establish an early, effective molecular marker-assisted selection system for guide dog breeding. This system will greatly improve the breeding efficiency and the successful training rate of guide dogs. This system will also provide the primary experimental data for behavioral genetics research.

导盲犬培育成功与犬的遗传特性有关。目前导盲犬的选育主要是靠行为测试方法，但该方法具有一定的主观性和不确定性，选育效率低，使导盲犬的培训成功率处于较低水平（约30%），成本居高不下（15-20万元/只），供不应求。神经类型是决定导盲犬选育成功与否的重要遗传因素，已知MAO、COMT及5-羟色胺能和多巴胺能系统相关基因与神经类型密切相关，如果能找到与上述基因相关的分子标记，通过这些遗传标记筛选备选导盲犬，将大大提升导盲犬的培育成功率。本研究以课题组已培训成功和未成功的拉布拉多犬为研究对象，用候选基因法对上述基因及其连锁DNA片段进行单核苷酸和微卫星多态性分析，找到拉布拉多犬四种神经类型的分子遗传标记并进行优化组合。在对幼犬进行选育的复核验证和优化基础上，初步建立快捷、有效的早期分子遗传标记选育体系。该体系的建立将极大提高导盲犬的选育效率和培训成功率，并为行为遗传学理论研究提供实验数据。

导盲犬培育成功与犬的遗传特性有关。目前导盲犬的选育主要依靠行为学测试方法，但该方法具有一定的主观性和不确定性，选育效率低，使导盲犬的培训成功率处于较低水平（约30%），成本居高不下（15-20万元/只），供不应求。神经类型是决定导盲犬选育成功与否的重要遗传因素，已知MAO、COMT及5-羟色胺能和多巴胺能系统相关基因与神经类型密切相关，如果能找到与上述基因相关的分子标记，通过这些遗传标记筛选备选导盲犬，将会提升导盲犬的培育成功率。本课题通过对DMA行为学测试体系的10个子测试，33个变量进行了改良，使其更适合拉布拉多犬和金毛猎犬三种神经类型（安静、活泼、胆小）的评判，目前已经完成改良DMA测试的犬142只，建立了犬血液基因组样本库（包含拉布拉多犬血液样本165只，金毛猎犬血液样本58只，黄金拉拉14只），可用于后期的犬性情遗传学鉴定体系建立。通过对典型神经类型犬的候选基因及其连锁DNA片段进行单核苷酸和微卫星多态性分析，发现COMT的216位点与482位点的基因型为GA-GA或AA-AA时，可对胆小性情的犬进行准确的判别。这为初步建立快捷、有效的早期分子遗传标记选育体系，提高导盲犬的选育效率和培训成功率，以及为犬行为遗传学研究提供实验数据等方面都具有重要的理论和实践意义。依据本项目的实施，部分研究成果已应用于中国导盲犬（大连）培训基地的犬行为学和遗传学鉴定的实际工作中的筛查科目，并已发表国内核心期刊论文11篇，已投稿SCI论文1篇，正申请发明专利1项。