Developmental and comparative study of hematopoiesis in the lamprey: insights into the evolutionary origin of hematopoiesis in vertebrates

造血是一个人从胚胎到成年的血细胞形成的过程。然而，尽管这是一种重要的动物生理现象，但我们的大部分知识都来自于对几个经典动物模型的研究，这些模型大多是有颌骨的脊椎动物的代表。考虑到这一点，我开始研究七鳃鳗，这是下巴脊椎动物的远亲，在血液系统方面还没有得到充分的研究。在2020财年，我完成了对七鳃鳗胚胎RNA-seq数据的分析，并确定了七鳃鳗中所有候选的造血标志物。在七鳃鳗胚胎发生过程中，我为所有可能的造血标志物生成了一组完整的表达模式。然后，我能够对七鳃鳗scl基因进行CRISPR敲除，这是其他脊椎动物中一种重要的造血因子，并获得了足够的样本来进行RNA-seq分析和原位杂交实验。虽然没有明显的突变表型，但血液变化是可以预料的。这些样本将在不久的将来被用来评估SCL在睫状孔血液发育中的作用，这将使我们能够进行与颌骨造血术的对比分析。

Hematopoiesis is the process by which the blood cells of an individual, from the embryo to adulthood, are formed. However, despite being a crucial physiological phenomenon ofanimals, most of our knowledge derives from studies using a handful of classic animal models, mostly representatives of jawed vertebrates. Withthis in mind, I set to study the lamprey, long-distant relative of jawed vertebrates that is understudied in terms of the blood system. In FY2020 I completed the analysis of RNA-seq data from lamprey embryos and identified all candidate hematopoietic markers in the lamprey. I generated a complete panel of expression patterns for all putative hematopoietic markers during lamprey embryogenesis. I was then able to perform CRISPR knock-outs of lamprey Scl gene, an important hematopoietic factor in other vertebrates, and obtained enough samples to carry out RNA-seq analysis as well as in situ hybridization experiments. Although there was no apparent mutant phenotype, blood alterations are expected. These samples will be used in the near future to assess the function of Scl in blood development in cyclostomes, what will enable comnparative analysis with gnathostome hematopoiesis.