Donovan David M, Kerr David E, Wall Robert J
Biotechnology and Germplasm Laboratory, Agricultural Research Service, United States Department of Agriculture, Beltsville, Maryland 20705, USA.
Transgenic Res. 2005 Oct;14(5):563-7. doi: 10.1007/s11248-005-0670-8.
Mastitis is a disease of the mammary gland caused by pathogens that find their way into the lumen of the gland through the teat canal. Mammary gland infections cost the US dairy industry approximately $2 billion dollars annually and have a similar impact in Europe. In the absence of effective treatments or breeding strategies to enhance mastitis resistance, we have created transgenic dairy cows that express lysostaphin in their mammary epithelium and secrete the antimicrobial peptide into milk. Staphylococcus aureus, a major mastitis pathogen, is exquisitely sensitive to lysostaphin. The transgenic cattle resist S. aureus mammary gland challenges, and their milk kills the bacteria, in a dose dependent manner. This first step in protecting cattle against mastitis will be followed by introduction of other genes to deal with potential resistance issues and other mastitis causing organisms. Care will be taken to avoid altering milk's nutritional and manufacturing properties. Multi-cistronic constructs may be required to achieve our goals as will other strategies possibly involving RNAi and gene targeting technology. This work demonstrates the possibility of using transgenic technology to address disease problems in agriculturally important species.
乳腺炎是一种由病原体引起的乳腺疾病，这些病原体通过乳头管进入乳腺管腔。乳腺感染每年给美国乳制品行业造成约20亿美元的损失，在欧洲也有类似影响。在缺乏有效治疗方法或提高乳腺炎抗性的育种策略的情况下，我们培育了在乳腺上皮中表达溶葡萄球菌素并将抗菌肽分泌到牛奶中的转基因奶牛。金黄色葡萄球菌是一种主要的乳腺炎病原体，对溶葡萄球菌素极为敏感。转基因牛能够抵抗金黄色葡萄球菌对乳腺的攻击，并且它们的牛奶能以剂量依赖的方式杀死这种细菌。在保护奶牛免受乳腺炎侵害的这第一步之后，将引入其他基因来处理潜在的抗性问题以及其他引起乳腺炎的生物体。将谨慎避免改变牛奶的营养和加工特性。可能需要多顺反子构建体以及其他可能涉及RNA干扰和基因靶向技术的策略来实现我们的目标。这项工作证明了利用转基因技术解决农业重要物种疾病问题的可能性。
