单细胞转录组高级分析一：多样本合并与批次校正

	library(Seurat)library(tidyverse)library(patchwork)dir.create('cluster1')dir.create('cluster2')dir.create('cluster3')set.seed(123)  #设置随机数种子，使结果可重复##==合并数据集==####使用目录向量合并dir = c('data/GSE139324_HNC/GSM4138110',         'data/GSE139324_HNC/GSM4138111',        'data/GSE139324_HNC/GSM4138128',        'data/GSE139324_HNC/GSM4138129',        'data/GSE139324_HNC/GSM4138148',        'data/GSE139324_HNC/GSM4138149',        'data/GSE139324_HNC/GSM4138162',        'data/GSE139324_HNC/GSM4138163',        'data/GSE139324_HNC/GSM4138168',        'data/GSE139324_HNC/GSM4138169')names(dir) = c('HNC01PBMC', 'HNC01TIL', 'HNC10PBMC', 'HNC10TIL', 'HNC20PBMC',                'HNC20TIL', 'PBMC1', 'PBMC2', 'Tonsil1', 'Tonsil2')counts <- Read10X(data.dir = dir)scRNA1 = CreateSeuratObject(counts, min.cells=1)dim(scRNA1)   #查看基因数和细胞总数#[1] 23603 19750 table([email protected]$orig.ident)  #查看每个样本的细胞数#HNC01PBMC  HNC01TIL HNC10PBMC  HNC10TIL HNC20PBMC  HNC20TIL     PBMC1     PBMC2   Tonsil1   Tonsil2 #     1725      1298      1750      1384      1530      1148      2445      2436      3325      2709

	#使用merge函数合并seurat对象scRNAlist <- list()#以下代码会把每个样本的数据创建一个seurat对象，并存放到列表scRNAlist里for(i in 1:length(dir)){counts <- Read10X(data.dir = dir[i])scRNAlist[[i]] <- CreateSeuratObject(counts, min.cells=1)}#使用merge函数讲10个seurat对象合并成一个seurat对象scRNA2 <- merge(scRNAlist[[1]], y=c(scRNAlist[[2]], scRNAlist[[3]],                 scRNAlist[[4]], scRNAlist[[5]], scRNAlist[[6]], scRNAlist[[7]],                 scRNAlist[[8]], scRNAlist[[9]], scRNAlist[[10]]))#dim(scRNA2)[1] 23603 19750table([email protected]$orig.ident)#HNC01PBMC  HNC01TIL HNC10PBMC  HNC10TIL HNC20PBMC  HNC20TIL     PBMC1     PBMC2   Tonsil1   Tonsil2 #     1725      1298      1750      1384      1530      1148      2445      2436      3325      2709

	scRNA1 <- NormalizeData(scRNA1)scRNA1 <- FindVariableFeatures(scRNA1, selection.method = "vst")scRNA1 <- ScaleData(scRNA1, features = VariableFeatures(scRNA1))scRNA1 <- RunPCA(scRNA1, features = VariableFeatures(scRNA1))plot1 <- DimPlot(scRNA1, reduction = "pca", group.by="orig.ident")plot2 <- ElbowPlot(scRNA1, ndims=30, reduction="pca") plotc <- plot1+plot2ggsave("cluster1/pca.png", plot = plotc, width = 8, height = 4)print(c("请选择哪些pc轴用于后续分析？示例如下：","pc.num=1:15"))#选取主成分pc.num=1:30

	##细胞聚类scRNA1 <- FindNeighbors(scRNA1, dims = pc.num) scRNA1 <- FindClusters(scRNA1, resolution = 0.5)table([email protected]$seurat_clusters)metadata <- [email protected]cell_cluster <- data.frame(cell_ID=rownames(metadata), cluster_ID=metadata$seurat_clusters)write.csv(cell_cluster,'cluster1/cell_cluster.csv',row.names = F)

	##非线性降维#tSNEscRNA1 = RunTSNE(scRNA1, dims = pc.num)embed_tsne <- Embeddings(scRNA1, 'tsne')   #提取tsne图坐标write.csv(embed_tsne,'cluster1/embed_tsne.csv')#group_by_clusterplot1 = DimPlot(scRNA1, reduction = "tsne", label=T) ggsave("cluster1/tSNE.png", plot = plot1, width = 8, height = 7)#group_by_sampleplot2 = DimPlot(scRNA1, reduction = "tsne", group.by='orig.ident') ggsave("cluster1/tSNE_sample.png", plot = plot2, width = 8, height = 7)#combinateplotc <- plot1+plot2ggsave("cluster1/tSNE_cluster_sample.png", plot = plotc, width = 10, height = 5)

	#UMAPscRNA1 <- RunUMAP(scRNA1, dims = pc.num)embed_umap <- Embeddings(scRNA1, 'umap')   #提取umap图坐标write.csv(embed_umap,'cluster1/embed_umap.csv') #group_by_clusterplot3 = DimPlot(scRNA1, reduction = "umap", label=T) ggsave("cluster1/UMAP.png", plot = plot3, width = 8, height = 7)#group_by_sampleplot4 = DimPlot(scRNA1, reduction = "umap", group.by='orig.ident')ggsave("cluster1/UMAP.png", plot = plot4, width = 8, height = 7)#combinateplotc <- plot3+plot4ggsave("cluster1/UMAP_cluster_sample.png", plot = plotc, width = 10, height = 5)

	#合并tSNE与UMAPplotc <- plot2+plot4+ plot_layout(guides = 'collect')ggsave("cluster1/tSNE_UMAP.png", plot = plotc, width = 10, height = 5)

	##scRNA2对象的降维聚类参考scRNA1的代码

	#scRNAlist是之前代码运行保存好的seurat对象列表，保存了10个样本的独立数据#数据整合之前要对每个样本的seurat对象进行数据标准化和选择高变基因for (i in 1:length(scRNAlist)) {    scRNAlist[[i]] <- NormalizeData(scRNAlist[[i]])    scRNAlist[[i]] <- FindVariableFeatures(scRNAlist[[i]], selection.method = "vst")}##以VariableFeatures为基础寻找锚点，运行时间较长scRNA.anchors <- FindIntegrationAnchors(object.list = scRNAlist)##利用锚点整合数据，运行时间较长scRNA3 <- IntegrateData(anchorset = scRNA.anchors)dim(scRNA3)#[1]  2000 19750    #有没有发现基因数据只有2000个了？这是因为seurat整合数据时只用2000个高变基因。#降维聚类的代码省略

	##==数据质控==#scRNA <- scRNA3  #以后的分析使用整合的数据进行##meta.data添加信息proj_name <- data.frame(proj_name=rep("demo2",ncol(scRNA)))rownames(proj_name) <- row.names([email protected])scRNA <- AddMetaData(scRNA, proj_name)

	##切换数据集DefaultAssay(scRNA) <- "RNA"

	##计算线粒体和红细胞基因比例scRNA[["percent.mt"]] <- PercentageFeatureSet(scRNA, pattern = "^MT-")#计算红细胞比例HB.genes <- c("HBA1","HBA2","HBB","HBD","HBE1","HBG1","HBG2","HBM","HBQ1","HBZ")HB_m <- match(HB.genes, rownames(scRNA@assays$RNA)) HB.genes <- rownames(scRNA@assays$RNA)[HB_m] HB.genes <- HB.genes[!is.na(HB.genes)] scRNA[["percent.HB"]]<-PercentageFeatureSet(scRNA, features=HB.genes) #head([email protected])col.num <- length(levels(as.factor([email protected]$orig.ident)))

	##绘制小提琴图#所有样本一个小提琴图用group.by="proj_name"，每个样本一个小提琴图用group.by="orig.ident"violin <-VlnPlot(scRNA, group.by = "proj_name",           features = c("nFeature_RNA", "nCount_RNA", "percent.mt","percent.HB"),          cols =rainbow(col.num),          pt.size = 0.01, #不需要显示点，可以设置pt.size = 0         ncol = 4) +          theme(axis.title.x=element_blank(), axis.text.x=element_blank(), axis.ticks.x=element_blank()) ggsave("QC/vlnplot_before_qc.pdf", plot = violin, width = 12, height = 6) ggsave("QC/vlnplot_before_qc.png", plot = violin, width = 12, height = 6)  plot1 <- FeatureScatter(scRNA, feature1 = "nCount_RNA", feature2 = "percent.mt")plot2 <- FeatureScatter(scRNA, feature1 = "nCount_RNA", feature2 = "nFeature_RNA")plot3 <- FeatureScatter(scRNA, feature1 = "nCount_RNA", feature2 = "percent.HB")pearplot <- CombinePlots(plots = list(plot1, plot2, plot3), nrow=1, legend="none") ggsave("QC/pearplot_before_qc.pdf", plot = pearplot, width = 12, height = 5) ggsave("QC/pearplot_before_qc.png", plot = pearplot, width = 12, height = 5)

	##设置质控标准print(c("请输入允许基因数和核糖体比例，示例如下：", "minGene=500", "maxGene=4000", "pctMT=20"))minGene=500maxGene=3000pctMT=10

	##数据质控scRNA <- subset(scRNA, subset = nFeature_RNA > minGene & nFeature_RNA < maxGene & percent.mt < pctMT)col.num <- length(levels(as.factor([email protected]$orig.ident)))violin <-VlnPlot(scRNA, group.by = "proj_name",         features = c("nFeature_RNA", "nCount_RNA", "percent.mt","percent.HB"),          cols =rainbow(col.num),          pt.size = 0.1,          ncol = 4) +          theme(axis.title.x=element_blank(), axis.text.x=element_blank(), axis.ticks.x=element_blank()) ggsave("QC/vlnplot_after_qc.pdf", plot = violin, width = 12, height = 6) ggsave("QC/vlnplot_after_qc.png", plot = violin, width = 12, height = 6)

	##==鉴定细胞类型==##library(SingleR)dir.create("CellType")refdata <- MonacoImmuneData()testdata <- GetAssayData(scRNA, slot="data")clusters <- [email protected]$seurat_clusters#使用Monaco参考数据库鉴定cellpred <- SingleR(test = testdata, ref = refdata, labels = refdata$label.main,                      method = "cluster", clusters = clusters,                      assay.type.test = "logcounts", assay.type.ref = "logcounts")celltype = data.frame(ClusterID=rownames(cellpred), celltype=cellpred$labels, stringsAsFactors = F)write.csv(celltype,"CellType/celltype_Monaco.csv",row.names = F)[email protected]$celltype_Monaco = "NA"for(i in 1:nrow(celltype)){[email protected][which([email protected]$seurat_clusters == celltype$ClusterID[i]),'celltype_Monaco'] <- celltype$celltype[i]}p1 = DimPlot(scRNA, group.by="celltype_Monaco", repel=T, label=T, label.size=5, reduction='tsne')p2 = DimPlot(scRNA, group.by="celltype_Monaco", repel=T, label=T, label.size=5, reduction='umap')p3 = p1+p2+ plot_layout(guides = 'collect')ggsave("CellType/tSNE_celltype_Monaco.png", p1, width=7 ,height=6)ggsave("CellType/UMAP_celltype_Monaco.png", p2, width=7 ,height=6)ggsave("CellType/celltype_Monaco.png", p3, width=10 ,height=5)#使用DICE参考数据库鉴定refdata <- DatabaseImmuneCellExpressionData()# load('~/database/SingleR_ref/ref_DICE_1561s.RData')# refdata <- ref_DICEtestdata <- GetAssayData(scRNA, slot="data")clusters <- [email protected]$seurat_clusterscellpred <- SingleR(test = testdata, ref = refdata, labels = refdata$label.main,                      method = "cluster", clusters = clusters,                      assay.type.test = "logcounts", assay.type.ref = "logcounts")celltype = data.frame(ClusterID=rownames(cellpred), celltype=cellpred$labels, stringsAsFactors = F)write.csv(celltype,"CellType/celltype_DICE.csv",row.names = F)[email protected]$celltype_DICE = "NA"for(i in 1:nrow(celltype)){[email protected][which([email protected]$seurat_clusters == celltype$ClusterID[i]),'celltype_DICE'] <- celltype$celltype[i]}p4 = DimPlot(scRNA, group.by="celltype_DICE", repel=T, label=T, label.size=5, reduction='tsne')p5 = DimPlot(scRNA, group.by="celltype_DICE", repel=T, label=T, label.size=5, reduction='umap')p6 = p3+p4+ plot_layout(guides = 'collect')ggsave("CellType/tSNE_celltype_DICE.png", p4, width=7 ,height=6)ggsave("CellType/UMAP_celltype_DICE.png", p5, width=7 ,height=6)ggsave("CellType/celltype_DICE.png", p6, width=10 ,height=5)#对比两种数据库鉴定的结果p8 = p1+p4ggsave("CellType/Monaco_DICE.png", p8, width=12 ,height=5)

	##保存数据saveRDS(scRNA,'scRNA.rds')