英國科學(xué)家亞歷山大·弗萊明發(fā)現(xiàn)的青霉素拯救了無數(shù)人的生命,，但英國研究人員最近發(fā)現(xiàn),，弗萊明最初發(fā)現(xiàn)的產(chǎn)生青霉素的真菌不是人們長期認(rèn)為的種類，它一直被叫錯了80多年,。
弗萊明1928年在倫敦圣瑪麗醫(yī)學(xué)院工作時(shí)發(fā)現(xiàn),，一種真菌所分泌的物質(zhì)可以殺死細(xì)菌，這種物質(zhì)就是后來被廣泛使用的青霉素,。此后,，科學(xué)界找到了能產(chǎn)生青霉素的“產(chǎn)黃青霉菌”，并一直認(rèn)為這就是弗萊明最初發(fā)現(xiàn)的菌種,。
圣瑪麗醫(yī)學(xué)院保留了弗萊明的真菌樣本,，該校并入英國帝國理工學(xué)院后，這些樣本也一直保存了下來,。帝國理工學(xué)院11月21日發(fā)布公報(bào)說,，該校研究人員對這些樣本進(jìn)行了基因分析，發(fā)現(xiàn)它并不是標(biāo)準(zhǔn)的“產(chǎn)黃青霉菌”,，而是與之非常相近的一個(gè)菌種,，由于之前沒有注意到，這個(gè)菌種還沒有得到命名,。
研究人員請全球各地的同行提供了當(dāng)?shù)厮鸭降漠a(chǎn)黃青霉菌樣本,，通過基因分析發(fā)現(xiàn)，雖然它們長期被認(rèn)為是一個(gè)物種,，但“產(chǎn)黃青霉菌”的名下可能有四個(gè)不同的物種,，它們非常相似，如果不使用基因手段難以辨別出來,。
參與研究的丹尼爾·亨克說,，這說明弗萊明非常幸運(yùn)，他不僅發(fā)現(xiàn)的是一種能產(chǎn)生青霉素的真菌,，其他研究者后續(xù)分離出的也正好是有相同功能的菌種,，如果碰上了別的菌種而無法重復(fù)實(shí)驗(yàn)結(jié)果，那么也許會有別的人在其他研究中報(bào)告發(fā)現(xiàn)青霉素。
他還表示,，這項(xiàng)發(fā)現(xiàn)說明這一類真菌有很強(qiáng)的生物多樣性,，這對研制新藥物來說是個(gè)好消息，可以探索這些青霉素的“親戚”是否能產(chǎn)生新的藥用物質(zhì),。相關(guān)研究報(bào)告已經(jīng)發(fā)表在學(xué)術(shù)刊物《分子生態(tài)學(xué)》上,。（生物谷 Bioon.com）
doi:10.1111/j.1365-294X.2011.05244.x
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Speciation despite globally overlapping distributions in Penicillium chrysogenum: the population genetics of Alexander Fleming’s lucky fungus
D. A. HENK, C. E. EAGLE, K. BROWN, M. A. VAN DEN BERG, P. S. DYER, S. W. PETERSON, M. C. FISHER
Keywords:Alexander Fleming;asexual;microsatellite;Penicillium flemingii;speciationAbstractEighty years ago, Alexander Fleming described the antibiotic effects of a fungus that had contaminated his bacterial culture, kick starting the antimicrobial revolution. The fungus was later ascribed to a putatively globally distributed asexual species, Penicillium chrysogenum. Recently, the species has been shown to be genetically diverse, and possess mating‐ ype genes. Here, phylogenetic and population genetic analyses show that this apparently ubiquitous fungus is actually composed of at least two genetically distinct species with only slight differences detected in physiology. We found each species in air and dust samples collected in and around St Mary’s Hospital where Fleming worked. Genotyping of 30 markers across the genome showed that preserved fungal material from Fleming’s laboratory was nearly identical to derived strains currently in culture collections and in the same distinct species as a wild progenitor strain of current penicillin producing industrial strains rather than the type species P. chrysogenum. Global samples of the two most common species were found to possess mating‐ ype genes in a near 1:1 ratio, and show evidence of recombination with little geographic population subdivision evident. However, no hybridization was detected between the species despite an estimated time of divergence of less than 1 MYA. Growth studies showed significant interspecific inhibition by P. chrysogenum of the other common species, suggesting that competition may facilitate species maintenance despite globally overlapping distributions. Results highlight under‐\recognized diversity even among the best‐known fungal groups and the potential for speciation despite overlapping distribution.
