Costa Milce, Borges Clayton L, Bailão Alexandre M, Meirelles Gabriela V, Mendonça Yuri A, Dantas Sabrina F I M, de Faria Fabrícia P, Felipe Maria S S, Molinari-Madlum Eugênia E W I, Mendes-Giannini Maria J S, Fiuza Rogério B, Martins Wellington S, Pereira Maristela, Soares Célia M A
Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, 74001-970, Goiânia, Goiás, Brazil.
Laboratório de Biologia Molecular, Universidade de Brasília, Brasília, Brazil.
Microbiology (Reading). 2007 Dec;153(Pt 12):4194-4207. doi: 10.1099/mic.0.2007/009332-0.
Paracoccidioides brasiliensis is a fungal human pathogen with a wide distribution in Latin America. It causes paracoccidioidomycosis, the most widespread systemic mycosis in Latin America. Although gene expression in P. brasiliensis had been studied, little is known about the genome sequences expressed by this species during the infection process. To better understand the infection process, 4934 expressed sequence tags (ESTs) derived from a non-normalized cDNA library from P. brasiliensis (isolate Pb01) yeast-phase cells recovered from the livers of infected mice were annotated and clustered to a UniGene (clusters containing sequences that represent a unique gene) set with 1602 members. A large-scale comparative analysis was performed between the UniGene sequences of P. brasiliensis yeast-phase cells recovered from infected mice and a database constructed with sequences of the yeast-phase and mycelium transcriptome (isolate Pb01) (https://dna.biomol.unb.br/Pb/), as well as with all public ESTs available at GenBank, including sequences of the P. brasiliensis yeast-phase transcriptome (isolate Pb18) (http://www.ncbi.nlm.nih.gov/). The focus was on the overexpressed and novel genes. From the total, 3184 ESTs (64.53%) were also present in the previously described transcriptome of yeast-form and mycelium cells obtained from in vitro cultures (https://dna.biomol.unb.br/Pb/) and of those, 1172 ESTs (23.75% of the described sequences) represented transcripts overexpressed during the infection process. Comparative analysis identified 1750 ESTs (35.47% of the total), comprising 649 UniGene sequences representing novel transcripts of P. brasiliensis, not previously described for this isolate or for other isolates in public databases. KEGG pathway mapping showed that the novel and overexpressed transcripts represented standard metabolic pathways, including glycolysis, amino acid biosynthesis, lipid and sterol metabolism. The unique and divergent representation of transcripts in the cDNA library of yeast cells recovered from infected mice suggests differential gene expression in response to the host milieu.
巴西副球孢子菌是一种在拉丁美洲广泛分布的致病性真菌。它可引发副球孢子菌病，这是拉丁美洲最为常见的系统性真菌病。尽管此前已对巴西副球孢子菌的基因表达进行过研究，但对于该菌在感染过程中所表达的基因组序列却知之甚少。为了更深入地了解感染过程，研究人员对从感染小鼠肝脏中分离得到的巴西副球孢子菌（菌株Pb01）酵母相细胞的非标准化cDNA文库中获取的4934个表达序列标签（EST）进行了注释，并将其聚类到一个包含1602个成员的单基因簇（UniGene，即包含代表单一基因的序列的簇）中。研究人员对从感染小鼠体内分离得到的巴西副球孢子菌酵母相细胞的单基因序列，与一个由酵母相和菌丝体转录组序列（菌株Pb01）构建的数据库（https://dna.biomol.unb.br/Pb/），以及GenBank中所有可用的公共EST进行了大规模比较分析，其中包括巴西副球孢子菌酵母相转录组序列（菌株Pb18）（http://www.ncbi.nlm.nih.gov/）。重点关注了过表达基因和新基因。在这些EST中，共有3184个（64.53%）也存在于先前描述的从体外培养物中获得的酵母形式和菌丝体细胞的转录组中（https://dna.biomol.unb.br/Pb/），其中1172个EST（占所描述序列的23.75%）代表在感染过程中过表达的转录本。比较分析确定了1750个EST（占总数的35.47%），包括649个单基因序列，代表了巴西副球孢子菌的新转录本，此前在公共数据库中该菌株或其他菌株均未描述过。KEGG通路映射显示，新的和过表达的转录本代表了标准代谢途径，包括糖酵解、氨基酸生物合成、脂质和固醇代谢。从感染小鼠体内分离得到的酵母细胞cDNA文库中转录本的独特和差异表达表明，基因表达因宿主环境而存在差异。
