The aim of the project is to set up a first-ever single-cell isoform atlas for human and other organisms such as pig, mouse, etc. data. There is currently no study has been published to cover a full spectrum of single-cell splicing variants across tissues and across organisms. To fill in the gap, we will carry out in-depth assessments of splicing variants across tissues and across organisms, and identify splicing variants that are differentially expressed at isoform level yet homogeneously expressed at gene-level. Besides, we will also identify cell-type-specific, tissue-specific, and organism-specific variants at the single-cell level.