ABSTRACT: Purpose: The goal of this study is to compare and examine the transcriptional profiles in control versus Cic-deficient B cells, specifically splenic B-1a and Fo B cells, by mRNA sequencing. Methods: Splenic B-1a (IgM+, CD19+, CD5+, CD43+) and Fo B (B220+, CD93-, CD23+, CD21lo-mid) cells were sorted by a MoFlo-XDP (Beckman Coulter). Total RNA was extracted using TRIzol Reagent (GeneAll), according to the manufacturer’s instructions. The DNA library for mRNA sequencing was generated using SMART-seq v4 Ultra Input RNA Kit (Clontech, for B-1a cells) and TruSeq RNA Sample Prep Kit v2 (Illumina, for Fo B cells). DNA libraries were multiplexed and pooled for sequencing on the Illumina Hiseq 4000 platform. Results: Trimmed reads were mapped to mouse reference genome (mm10 RefSeq) with HISAT2, a splice-aware aligner, and transcripts were assembled by StringTie with aligned reads, for known transcripts, novel transcripts, and alternatively spliced transcripts. A total of 712 genes were differentially expressed in Cic-null B-1a cells (325 upregulated and 387 downregulated), while 357 genes were differentially expressed in Cic-deficient Fo B cells (180 upregulated and 178 downregulated) when compared with their respective control cells (fold change >1.2 and P < 0.05). Several known CIC target genes, including Etv1, Etv4, Etv5, Spry4, Spred1, Spred2, Dusp4, Dusp6, and Per2, were included in the list of the upregulated differentially expressed genes (DEGs) in either Cic-null B-1a or Fo B cells or both, validating the reliability of RNA sequencing results. Conclusions: Our study presents the first comparative gene expression analysis of B-1a and Fo B cells from control and B cell-specific Cic-deficient mice. We concluded that CIC deficiency promotes B-1a cell development through enhancing the BCR signaling pathway. The data reported here also provide references for the gene expression profiles of murine B-1a and Fo B cells.
