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

造血是一个人的血细胞从胚胎到成年形成的过程。然而，尽管这是一种至关重要的动物生理现象，但我们的大部分知识都来自于使用少数经典动物模型的研究，这些模型主要是有颌脊椎动物的代表。考虑到这一点，我开始研究七鳃鳗，它是有颌脊椎动物的远亲，在血液系统方面研究不足。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记物。我在七鳃鳗胚胎发生过程中生成了一个完整的表达模式面板，用于所有假定的造血标记。然后，我可以对其他脊椎动物重要的造血因子七鳃鳗的Scl基因进行CRISPR敲除，并获得足够的样本进行RNA-seq分析和原位杂交实验。虽然没有明显的突变表型，但血液改变是预期的。这些样本将在不久的将来用于评估Scl在环口血液发育中的功能，这将使与颌口造血的比较分析成为可能。

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.