Simultaneous transcription of duplicated var2csa gene copies in individual Plasmodium falciparum parasites.
Simultaneous transcription of duplicated var2csa gene copies in individual Plasmodium falciparum parasites.
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DOI：
10.1186/gb-2009-10-10-r117
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发表时间：
2009
期刊：
影响因子：
12.3
通讯作者：
Chen Q
中科院分区：
文献类型：
--
作者：
Brolin KJ;Ribacke U;Nilsson S;Ankarklev J;Moll K;Wahlgren M;Chen Q
在一株恶性疟原虫中，重复的var2csa基因同时转录，挑战了var基因相互排斥转录的教条，单核苷酸多态性在重复基因中很常见，导致功能保存、改变或沉默。恶性疟原虫基因var2csa和Pf332在HB3疟原虫的单倍体基因组中被复制。虽然Pf332的分子功能仍有待阐明，但已知VAR2CSA是胎盘寄生虫隔离的主要粘附素。这些基因复制后的序列变异为分析等位基因特异性转录提供了判别可能性，有助于了解基因剂量对寄生虫生物学的影响。我们展示了一种结合实时PCR等位基因识别和鉴别RNA-FISH的方法来区分恶性疟原虫高度相似的基因拷贝。在群体水平和个体细胞中，复制的var2csa变异体同时转录，具有活性基因和相应转录物的核共定位。这表明了重复基因的转录功能，挑战了var基因转录互斥的教条，并提出了抗原变异背后的机制，至少在重复和高度相似的var2csa基因方面。传统上，等位基因鉴别法被用于研究二倍体基因组的合子性。本文提出的检测方法成功地应用于鉴定和评估恶性疟原虫单倍体基因组中重复基因的转录活性。FISH的等位基因识别和基因或转录本定位不仅提供了对毒力相关var基因等基因转录调控的深入了解，而且还表明这种敏感和精确的方法可用于进一步研究基因组动力学和基因调控。
Duplicated var2csa genes in one strain of Plasmodium falciparum are simultaneously transcribed, challenging the dogma of mutual exclusive var gene transcription Single nucleotide polymorphisms are common in duplicated genes, causing functional preservation, alteration or silencing. The Plasmodium falciparum genes var2csa and Pf332 are duplicated in the haploid genome of the HB3 parasite line. Whereas the molecular function of Pf332 remains to be elucidated, VAR2CSA is known to be the main adhesin in placental parasite sequestration. Sequence variations introduced upon duplication of these genes provide discriminative possibilities to analyze allele-specific transcription with a bearing towards understanding gene dosage impact on parasite biology. We demonstrate an approach combining real-time PCR allelic discrimination and discriminative RNA-FISH to distinguish between highly similar gene copies in P. falciparum parasites. The duplicated var2csa variants are simultaneously transcribed, both on a population level and intriguingly also in individual cells, with nuclear co-localization of the active genes and corresponding transcripts. This indicates transcriptional functionality of duplicated genes, challenges the dogma of mutually exclusive var gene transcription and suggests mechanisms behind antigenic variation, at least in respect to the duplicated and highly similar var2csa genes. Allelic discrimination assays have traditionally been applied to study zygosity in diploid genomes. The assays presented here are instead successfully applied to the identification and evaluation of transcriptional activity of duplicated genes in the haploid genome of the P. falciparum parasite. Allelic discrimination and gene or transcript localization by FISH not only provide insights into transcriptional regulation of genes such as the virulence associated var genes, but also suggest that this sensitive and precise approach could be used for further investigation of genome dynamics and gene regulation.
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影响因子：
12.3
作者：
Dharia NV;Sidhu AB;Cassera MB;Westenberger SJ;Bopp SE;Eastman RT;Plouffe D;Batalov S;Park DJ;Volkman SK;Wirth DF;Zhou Y;Fidock DA;Winzeler EA
通讯作者：
Winzeler EA
影响因子：
5.6
作者：
Dzikowski, Ron;Deitsch, Kirk W.
通讯作者：
Deitsch, Kirk W.
影响因子：
64.5
作者：
BARUCH, DI;PASLOSKE, BL;HOWARD, RJ
通讯作者：
HOWARD, RJ
影响因子：
56.9
作者：
Fried, M;Duffy, PE
通讯作者：
Duffy, PE
影响因子：
30.8
作者：
Mu, Jianbing;Awadalla, Philip;Su, Xin-zhuan
通讯作者：
Su, Xin-zhuan