Ricci Lorenzo, Chaurasia Ankita, Lapébie Pascal, Dru Philippe, Helm Rebecca R, Copley Richard R, Tiozzo Stefano
CNRS, Sorbonne Universités, UPMC Univ Paris 06, Laboratoire de Biologie du Développement de Villefranche-sur-mer, Observatoire Océanographique, 06230, Villefranche-sur-mer, France.
Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA.
Sci Rep. 2016 Jun 6;6:27357. doi: 10.1038/srep27357.
Organisms that have evolved alternative modes of reproduction, complementary to the sexual mode, are found across metazoans. The chordate Botryllus schlosseri is an emerging model for asexual development studies. Botryllus can rebuild its entire body from a portion of adult epithelia in a continuous and stereotyped process called blastogenesis. Anatomy and ontogenies of blastogenesis are well described, however molecular signatures triggering this developmental process are entirely unknown. We isolated tissues at the site of blastogenesis onset and from the same epithelia where this process is never triggered. We linearly amplified an ultra-low amount of mRNA (<10ng) and generated three transcriptome datasets. To provide a conservative landscape of transcripts differentially expressed between blastogenic vs. non-blastogenic epithelia we compared three different mapping and analysis strategies with a de novo assembled transcriptome and partially assembled genome as references, additionally a self-mapping strategy on the dataset. A subset of differentially expressed genes were analyzed and validated by in situ hybridization. The comparison of different analyses allowed us to isolate stringent sets of target genes, including transcripts with potential involvement in the onset of a non-embryonic developmental pathway. The results provide a good entry point to approach regenerative event in a basal chordate.
在后生动物中发现了一些进化出与有性生殖模式互补的替代生殖模式的生物。海鞘Botryllus schlosseri是无性发育研究的新兴模型。Botryllus可以通过一个连续且模式化的称为芽球形成的过程,从成年上皮细胞的一部分重建其整个身体。芽球形成的解剖学和个体发育过程已得到充分描述,然而触发这一发育过程的分子特征却完全未知。我们在芽球形成开始的部位以及从未触发该过程的相同上皮组织中分离出组织。我们对极少量的mRNA(<10ng)进行线性扩增,并生成了三个转录组数据集。为了提供芽球形成上皮细胞与非芽球形成上皮细胞之间差异表达转录本的保守概况,我们将三种不同的映射和分析策略与一个从头组装的转录组和部分组装的基因组作为参考进行比较,此外还对数据集进行了自映射策略。通过原位杂交对一部分差异表达基因进行了分析和验证。不同分析方法的比较使我们能够分离出严格的目标基因集,包括可能参与非胚胎发育途径起始的转录本。这些结果为研究基础脊索动物的再生事件提供了一个良好的切入点。