浙江大學農學院昆蟲研究所陳學新教授課題組在一項關于蜜蜂的研究中發(fā)現(xiàn),，中華蜜蜂之所以比意大利蜜蜂具有更強的抗寒能力和抗病能力,，是因為意大利蜜蜂在更為長期的馴化過程中喪失了某些基因,。據(jù)悉，這一發(fā)現(xiàn)首次用實驗的方式證實了長期馴化可能導致生物基因多樣性降低的理論假設,。
中華蜜蜂
據(jù)介紹,，中華蜜蜂和意大利蜜蜂都起源于約1000萬年前的亞洲，是一對非常相近的“姐妹”物種,。由于蜂蜜產量高,，易于管理，意大利蜜蜂很早就被人類馴化飼養(yǎng),，目前馴養(yǎng)范圍遍及全世界，已經沒有野生種群,。而作為中國土生土長的重要蜜蜂種類,，中華蜜蜂雖然也被人類馴化飼養(yǎng)，但目前仍然存在野生種群,。此前科學家在研究中發(fā)現(xiàn),，中華蜜蜂比意大利蜜蜂更加耐寒，更能抵御病害浸染和螨蟲危害,，并能為更多種類的植物尤其是高山植物傳授花粉,。
陳學新教授課題組經過四年的研究認為，蜜蜂體內與免疫相關的物質——抗菌肽是導致這對“姐妹”物種存在差異的重要線索,。該課題組利用分子生物學,、比較基因組學和生物信息學等手段，克隆并鑒定了中華蜜蜂和意大利蜜蜂的體內基因都來自4個抗菌肽基因家族,。這些基因對革蘭氏陰性和陽性菌,，其中包括一些人類疾病的致病菌都具有抗菌活性。其不同之處在于,，中華蜜蜂體內存在87個不同的基因,，共編碼26種不同的抗菌肽；意大利蜜蜂則為16個基因,、11種抗菌肽,。
陳學新說，抗菌肽是生物體內普遍存在的、在免疫防御體系中發(fā)揮重要作用的生物活性物質,。由于這兩種蜜蜂的抗菌肽家族具有明顯的不同,，當他們同時受到病原侵襲時，中華蜜蜂會因其具有明顯的抗菌肽基因優(yōu)勢和更為豐富的抗菌肽物質免受其害,。
該課題組的相關論文近日發(fā)表在美國《公共科學圖書館·綜合》（PLoS ONE）雜志上,。雜志的評審專家認為，該研究首次全部鑒定了一個物種所有抗菌肽因家族的系統(tǒng)研究,，獲得了有趣的科學發(fā)現(xiàn)并富有重要價值,，在實踐上為進一步保護和利用蜜蜂及其重要的抗菌類物質提供了重要的科學依據(jù)。（生物谷Bioon.com）
生物谷推薦原始出處：
PLoS ONE 4(1): e4239. doi:10.1371/journal.pone.0004239
Antimicrobial Peptide Evolution in the Asiatic Honey Bee Apis cerana
Peng Xu, Min Shi, Xue-xin Chen*
Institute of Insect Sciences, Zhejiang University, Hangzhou, Zhejiang, China
Abstract
The Asiatic honeybee, Apis cerana Fabricius, is an important honeybee species in Asian countries. It is still found in the wild, but is also one of the few bee species that can be domesticated. It has acquired some genetic advantages and significantly different biological characteristics compared with other Apis species. However, it has been less studied, and over the past two decades, has become a threatened species in China. We designed primers for the sequences of the four antimicrobial peptide cDNA gene families (abaecin, defensin, apidaecin, and hymenoptaecin) of the Western honeybee, Apis mellifera L. and identified all the antimicrobial peptide cDNA genes in the Asiatic honeybee for the first time. All the sequences were amplified by reverse transcriptase-polymerase chain reaction (RT-PCR). In all, 29 different defensin cDNA genes coding 7 different defensin peptides, 11 different abaecin cDNA genes coding 2 different abaecin peptides, 13 different apidaecin cDNA genes coding 4 apidaecin peptides and 34 different hymenoptaecin cDNA genes coding 13 different hymenoptaecin peptides were cloned and identified from the Asiatic honeybee adult workers. Detailed comparison of these four antimicrobial peptide gene families with those of the Western honeybee revealed that there are many similarities in the quantity and amino acid components of peptides in the abaecin, defensin and apidaecin families, while many more hymenoptaecin peptides are found in the Asiatic honeybee than those in the Western honeybee (13 versus 1). The results indicated that the Asiatic honeybee adult generated more variable antimicrobial peptides, especially hymenoptaecin peptides than the Western honeybee when stimulated by pathogens or injury. This suggests that, compared to the Western honeybee that has a longer history of domestication, selection on the Asiatic honeybee has favored the generation of more variable antimicrobial peptides as protection against pathogens.
