Genome Scale Patterns of Recombination between Coinfecting Vaccinia Viruses
Genome Scale Patterns of Recombination between Coinfecting Vaccinia Viruses
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DOI：
10.1128/jvi.00022-14
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发表时间：
2014-05-01
影响因子：
5.4
通讯作者：
Evans, David H.
中科院分区：
文献类型：
--
作者：
Qin, Li;Evans, David H.
重组在病毒进化中起着至关重要的作用。它有助于避免遗传衰退并创造新的表型。这促进了生存，基因组测序表明重组促进了人类病原体的进化，包括天花病毒等正痘病毒。重组也可用于绘制基因图谱，但尽管重组痘病毒很容易在培养物中产生，但以这种方式绘制痘苗病毒（VACV）基因组图谱的传统尝试却收效甚微。我们对 VACV 菌株 Tian Tan 和 Dryvax 在不同条件下杂交形成的重组体进行了测序。这些是共感染细胞中的单轮生长、五轮连续传代，或使用麻风痘病毒介导的 DNA 再激活获得的重组体。我们的研究表明，重组体包含 DNA 拼凑而成，交换次数随着传代而增加。进一步传代还选择了天坛 DNA，并与斑块大小增加相关。通过单轮共感染产生的重组体包含不成比例数量的短转换轨道（< 1 kbp），并表现出每 12 kbp 1 次交换，接近文献中每 8 kbp 1 次交换。这项研究的一个副产品是还检测到了罕见的突变。 VACV 复制产生类似于每个复制周期复制的每个核苷酸 1 x 10(-8) 突变，以及类似于每 70 轮传代 1 个大 (21 kbp) 缺失。使用 DNA 重新激活产生的病毒与使用普通方法产生的重组体似乎没有什么不同。这种方法的一个吸引人的特点是，当它与特定表型的选择相结合时，它提供了一种绘制和剖析更复杂病毒性状的方法。
Recombination plays a critical role in virus evolution. It helps avoid genetic decline and creates novel phenotypes. This promotes survival, and genome sequencing suggests that recombination has facilitated the evolution of human pathogens, including orthopoxviruses such as variola virus. Recombination can also be used to map genes, but although recombinant poxviruses are easily produced in culture, classical attempts to map the vaccinia virus (VACV) genome this way met with little success. We have sequenced recombinants formed when VACV strains Tian Tan and Dryvax are crossed under different conditions. These were a single round of growth in coinfected cells, five rounds of sequential passage, or recombinants obtained using leporipoxvirus-mediated DNA reactivation. Our studies showed that recombinants contain a patchwork of DNA, with the number of exchanges increasing with passage. Further passage also selected for TianTan DNA and correlated with increased plaque size. The recombinants produced through a single round of coinfection contain a disproportionate number of short conversion tracks (< 1 kbp) and exhibited 1 exchange per 12 kbp, close to the similar to 1 per 8 kbp in the literature. One by-product of this study was that rare mutations were also detected; VACV replication produces similar to 1 x 10(-8) mutation per nucleotide copied per cycle of replication and similar to 1 large (21 kbp) deletion per 70 rounds of passage. Viruses produced using DNA reactivation appeared no different from recombinants produced using ordinary methods. An attractive feature of this approach is that when it is combined with selection for a particular phenotype, it provides a way of mapping and dissecting more complex virus traits.