A bright day with some bright ideas
Transposable elements (TEs) are repetitive DNA sequences able to ‘jump’ in the host genome. They contribute to genome plasticity and evolution in many different ways, by bringing new regulatory sequences in the vicinity of genes or by generating chromosomal rearrangements. They are found in all sequenced organisms to date, and represent a variable proportion of the genomes: from only 3% in yeast to 45% in human and more than 85% in maize and wheat.
For a long time TEs were considered as junk DNA, without biological function besides the harmful effects they generate. In the last years, there has been an explosion of interest for TEs and their functions in the genome.
The 3rd International Congress on Transposable Elements (ICTE) in Saint-Malo (France) has illustrated this shift in focus. From the 16th to the 19th of April 2016, a bright sunshine welcomed more than 150 researchers, engineers and students from all over the world to share their knowledge on TEs in bacteria, fungi, animals and plants, through numerous talks and posters.
谈论什么？
戴维·鲍尔科姆爵士（David Baulcombe）概述了小RNA在植物中TES的转换沉默途径中的演变和中心作用
ICTE 2016 started off strong with a presentation bySir David Baulcombe，，，，who gave an overview of the evolution and the central role of small RNAs in transgenerational silencing pathways of TEs in plants, notably in tomato.
This introduction highlighted the importance of TEs in adaptive processes and during the meeting, the positive evolutionary impact of TEs was discussed in a broad range of species. In mammals,CéDric Feschottehas shown how TEs participate in remodeling the genome and acquiring new adaptive roles for the host.
他的实验室表明，人类基因组中的内源性逆转录病毒（HERV）能够结合STAT1，这是涉及免疫反应的干扰素（IFN）途径的效应子。IFN激活基因中HERV的富集表明它们是基因表达增强子的作用，因此，它们在调节基本免疫系统基因的调节中的意义。
此外，亨利·莱文提出了酵母逆转录子的例子Tf1这是针对环境变化的靶向应力反应基因的启动子区域。确实，在存在钴的情况下，已知诱导DNA损伤的有毒金属，Tf1活性大大增加，导致涉及TOR途径的基因的转录上调，从而赋予对这种应激的抗性。
该节目的明星无疑是Line-1（L1），这是仍活跃在人类中的三个移动元素家族之一。
该节目的明星无疑是Line-1（L1），这是仍活跃在人类中的三个移动元素家族之一。L1的活性是众所周知的，并讨论了该活动的下游效应。
Geoffrey J. Faulkner提出了一个单细胞返回跨丙座捕获测序分析（RC-SEQ），并显示了证据表明，在所有细胞中胚胎发生后通常受到严重抑制的L1可以在海马和皮质神经元中动员，从而有助于细胞镶嵌。他建议L1可能参与建立和微调神经元网络。
迪迪尔·特罗诺（Didier Trono）表明特定的转录因子KRAB-ZFP与TES结合，该因子可以作为组织特异性增强子的作用，并调节其在人类胚胎干细胞以及导致KRAB-ZFP介导的分化的成年组织中的转座。这些转录因素和TES一起在包括人类在内的几种物种的规范和演变中起着重要作用。这两个示例不仅在代际多样性中，而且在同一生物体的细胞之间也有明显的含义。
Uncovering the evolutionary history
国会期间强调的另一个方面是关于TE如何促进物种的进化。Leandro Quadrana展示了如何利用全基因组关联研究（GWAS）来研究整个进化史的转位运动。
It appears that in theArabidopsisgenome, a huge part of TEs had contributed to new insertions in recent history.
It appears that in theArabidopsisgenome, a huge part of TEs had contributed to new insertions in recent history. In addition, the transposition activity of TEs varied between different accessions ofArabidopsis thaliana并且可以与环境和遗传因素有关。这突出了动员在一个物种中观察到的遗传多样性中的影响。
继续这样做，奥利维尔·帕纳德（Olivier Panaud）presented the role of TEs in the variation of genome sizes in plants. He had analyzed the transpositional history inOryzaspecies over 15 million years of evolution pointing out not only the new insertions due to TEs but also their elimination rate, bringing to light a striking picture of TE turn-over during evolution. This kind of analysis represents the future challenge in better understanding how TEs shape eukaryotic genomes and further identifying the fundamental roles of TEs in adaptive evolution.
The non-self-recognition systems found in prokaryotes have led to many new applications in the field of applied biology. In particular, the CRISPR-Cas system discovery byEmmanuelle Charpentier是最近在ICTE 2016上很好地说明的最近历史上的主要突破之一。
在细菌中发现的这种机制导致了科学革命，因为它代表了一种强大的基因组工程技术，为长期以来一直认为是不可能的过程打开了大门。CRISPR-CAS系统允许靶向和修改非常精确的DNA序列in vivo。
由ZoltánIvics提出的另一个突破性过程指挥睡美人，参与改善基因分娩疗法的DNA转座子。
Another breakthrough process, presented byZoltán Ivics，指挥睡美人，参与改善基因分娩疗法的DNA转座子。这些试验使用改良病毒向患者输送基因的试验始于2000年，但由于逆转录病毒载体的整合选择性，这些试验通常是半成功的，这些逆转录病毒的选择性通常是针对主动转录单位的，因此激活了原始结肠基因并导致癌症。
睡美人是解决这个问题的有趣解决方案；它以几乎随机的方式整合，但是知道只有1％的人类基因组由编码序列组成，有害整合的风险非常低。这里的共识是，世界正在开放基于TE基因疗法的新时代。
学术严谨和研究卓越
After 4 sunny days of intense exchanges between guests of honor, researchers and PhD or postdoctoral fellows, the congress wrapped up. The TE community is strengthened by its diversity and the organizers of ICTE 2016 had succeeded to combine academic rigor and research excellence with conviviality. We would like to extend thanks to all the organizers and participants of the ICTE 2016 and we hope to see you again at ICTE 2020.
Comments