Poláková Silvia, Blume Christian, Zárate Julián Alvarez, Mentel Marek, Jørck-Ramberg Dorte, Stenderup Jørgen, Piskur Jure
Department of Cell and Organism Biology, Lund University, SE-22362 Lund, Sweden.
Proc Natl Acad Sci U S A. 2009 Feb 24;106(8):2688-93. doi: 10.1073/pnas.0809793106. Epub 2009 Feb 9.
In eukaryotes, the number and rough organization of chromosomes is well preserved within isolates of the same species. Novel chromosomes and loss of chromosomes are infrequent and usually associated with pathological events. Here, we analyzed 40 pathogenic isolates of a haploid and asexual yeast, Candida glabrata, for their genome structure and stability. This organism has recently become the second most prevalent yeast pathogen in humans. Although the gene sequences were well conserved among different strains, their chromosome structures differed drastically. The most frequent events reshaping chromosomes were translocations of chromosomal arms. However, also larger segmental duplications were frequent and occasionally we observed novel chromosomes. Apparently, this yeast can generate a new chromosome by duplication of chromosome segments carrying a centromere and subsequently adding novel telomeric ends. We show that the observed genome plasticity is connected with antifungal drug resistance and it is likely an advantage in the human body, where environmental conditions fluctuate a lot.
在真核生物中，同一物种的分离株内染色体的数量和大致组织结构保存良好。新染色体的出现和染色体的丢失很少见，通常与病理事件有关。在这里，我们分析了40株单倍体无性酵母光滑念珠菌的致病分离株的基因组结构和稳定性。这种微生物最近已成为人类中第二常见的酵母病原体。尽管不同菌株之间的基因序列保守性良好，但它们的染色体结构却有很大差异。重塑染色体最常见的事件是染色体臂的易位。然而，较大的片段重复也很常见，偶尔我们还观察到新染色体。显然，这种酵母可以通过复制携带着丝粒的染色体片段并随后添加新的端粒末端来产生新染色体。我们表明，观察到的基因组可塑性与抗真菌药物耐药性有关，并且在人体这种环境条件波动很大的地方，它可能是一种优势。
