Seurat Single Cell Analysis

❌ 被严格禁止的执行方式

# 🚫 严格禁止：这些方式都不允许使用
/Library/Frameworks/R.framework/Resources/bin/R --slave -e "library(Seurat); print('error')"
R -e "library(Seurat); print('error')"
R --slave -e 'library(Seurat); print("error")'
/Library/Frameworks/R.framework/Resources/bin/R << EOF  # 🚫 必须使用单引号'EOF'
# code
EOF

🔍 为什么这是强制规则？

1. 📖 多行代码支持: 复杂的单细胞分析需要多行R脚本
2. 🛡️ 无转义问题: 避免引号和特殊字符的转义地狱
3. 🎨 代码格式保持: 缩进和换行完美保留
4. 🔧 环境隔离: --no-save --no-restore确保干净R会话
5. 🔒 字符串保护: 单引号'EOF'确保所有字符原样保留

🚨 重要原则：跨平台数据转换标准

数据转换黄金法则

• ✅ 只转换原始counts: 转换时使用layer="counts"，不转换标准化数据
• ✅ 目标平台标准化: 让目标平台(Scanpy)处理自己的标准化流程
• ✅ 状态自动检查: 每次加载后自动检查数据状态，避免重复标准化
• ✅ 检查后默认标准化: Seurat数据读取检查完后默认进行标准化，创建data layer
• ✅ 失败即终止: 数据状态无法识别时立即终止任务

为什么这个原则很重要？

• 🎯 保证数据完整性: 原始counts是单细胞分析的生物学基础
• 🔄 确保一致性: 跨平台使用相同的标准化方法
• 🛡️ 防止错误: 自动检测避免重复标准化或数据损坏
• 📊 可重现性: 任何人都可以从counts重新开始分析
• ⚙️ 标准化必需: Seurat分析需要data layer，检查后自动创建

When to Use This Skill

This skill should be used when:

• Working with single cell RNA-seq data in .rds or .rdata format
• Analyzing data in an R environment with Seurat
• Needing to perform standard single cell analysis workflows including quality control, normalization, clustering, and visualization
• Converting to H5AD format for cross-platform analysis

Prerequisites

This skill requires:

• System R installation at /Library/Frameworks/R.framework/Resources/bin/R with Seurat v5, clusterProfiler, and ggplot2 packages installed
• Single cell data in .rds or .rdata format
• Conda environment scanpy for H5AD conversion support (used by reticulate method)
• Python packages (scanpy, anndata) automatically installed in reticulate's cached environment

Core Capabilities

1. Data Loading

Load single cell data from .rds or .rdata files using Seurat v5.

2. Quality Control

Perform quality control analysis including:

• Cell filtering based on gene counts and mitochondrial percentage
• Visualization of QC metrics

3. Normalization and Feature Selection

• Normalize data using log normalization
• Identify highly variable genes

4. Dimensionality Reduction

• Scale data for PCA
• Perform principal component analysis

5. Clustering

• Find neighbors for clustering
• Cluster cells using the Louvain algorithm
• Visualize clusters with UMAP

6. Marker Identification

• Find marker genes for cell clusters
• Visualize gene expression patterns

7. Data Format Conversion

• Convert Seurat objects to H5AD format using custom reticulate functions
• Preserve metadata, expression matrices, and dimensional reductions
• Recommended method: Custom functions for 100% Seurat v5 compatibility

8. GO Enrichment Analysis

• Extract marker genes for specific clusters
• Perform Gene Ontology enrichment analysis using clusterProfiler
• Visualize enrichment results with dot plots and bar plots
• Create publication-quality GO visualizations with two styles:
  • Separate plots: Individual plots for BP, CC, MF categories
  • Combined plot: All three categories in one comprehensive figure

Usage Instructions

Setting Up the Environment

Before using this skill, ensure the system R environment is available with all required packages:

R Environment Configuration:

# Use the standard R path for this skill
R_EXECUTABLE <- "/Library/Frameworks/R.framework/Resources/bin/R"

# Load required libraries
library(Seurat)
library(clusterProfiler)
library(ggplot2)

# Check that packages are loaded
packageVersion("Seurat")
packageVersion("clusterProfiler")
packageVersion("ggplot2")

Conda Environment for Python Integration:

# Required: Source conda first, then activate scanpy environment
source ~/miniconda3/etc/profile.d/conda.sh
conda activate scanpy

📋 标准执行模板（强制要求）

⚠️ 注意：以下模板是唯一允许的执行方式

# 所有Seurat分析的标准模板（强制使用）
/Library/Frameworks/R.framework/Resources/bin/R --slave --no-save --no-restore << 'EOF'
# === 加载库 ===
library(Seurat)
library(dplyr)
library(clusterProfiler)

# === 数据加载 ===
seurat_obj <- readRDS('input_file.rds')

# === 数据检查 ===
cat('数据维度:', nrow(seurat_obj), '×', ncol(seurat_obj), '\n')
print(table(seurat_obj$celltype))

# === 分析流程 ===
# ... 您的分析代码

# === 结果导出 ===
write.table(results, 'output.tsv', sep = '\t', quote = FALSE, row.names = FALSE)
EOF

🚨 重要提醒：技能中的所有代码示例都必须遵循Here Document执行方式！

Loading Data

🚨 第一步：数据状态检查（必须执行）

任何Seurat数据读取后，必须首先检查数据状态，确保使用正确的数据类型：

# 数据状态检查函数
check_seurat_data_state <- function(seurat_obj, verbose = TRUE) {
  """
  检查Seurat对象的counts layer是否为整数（原始counts）

  返回:
  - 'raw_counts': counts layer包含整数，是原始counts数据
  - 'normalized': counts layer已被标准化，需要谨慎处理
  - 'unknown': 数据状态无法识别
  """

  if (verbose) {
    cat('🔍 检查Seurat数据状态...\n')
    cat('数据维度:', nrow(seurat_obj), '基因 ×', ncol(seurat_obj), '细胞\n')
  }

  # 检查counts layer
  if ('counts' %in% Layers(seurat_obj)) {
    counts_matrix <- GetAssayData(seurat_obj, layer = 'counts')
    max_val <- max(counts_matrix)
    is_integer <- all(counts_matrix == round(counts_matrix))

    if (verbose) {
      cat('Counts layer信息:\n')
      cat('  最大值:', max_val, '\n')
      cat('  是否为整数:', is_integer, '\n')
      cat('  数据类型:', class(counts_matrix), '\n')
    }

    if (max_val > 20 && is_integer) {
      if (verbose) cat('✅ 检测到原始counts数据\n')
      return('raw_counts')
    } else if (max_val <= 10) {
      if (verbose) cat('⚠️  检测到已标准化数据\n')
      return('normalized')
    } else {
      if (verbose) cat('❌ 数据状态未知\n')
      return('unknown')
    }
  } else {
    if (verbose) cat('❌ 未找到counts layer\n')
    return('no_counts')
  }
}

# 使用示例
data_state <- check_seurat_data_state(seurat_obj)

if (data_state != 'raw_counts') {
  stop('❌ 数据不是原始counts，请检查数据来源')
}

标准数据加载流程

# For .rds files
data <- readRDS("path/to/your/file.rds")

# For .rdata files
load("path/to/your/file.rdata")
# The loaded object will be available in the environment

# ⚠️ 重要：加载后立即检查数据状态
data_state <- check_seurat_data_state(data)

if (data_state == 'raw_counts') {
  cat('✅ 数据验证通过，进行默认标准化...\n')
  # 🔄 **默认标准化流程**: 检查后自动进行标准化
  data <- NormalizeData(data, normalization.method = "LogNormalize", scale.factor = 10000)
  data <- FindVariableFeatures(data, selection.method = "vst", nfeatures = 2000)
  cat('✅ 标准化完成，data layer已创建\n')
} else if (data_state == 'normalized') {
  cat('✅ 数据已标准化，跳过标准化步骤\n')
} else {
  stop('❌ 数据验证失败，终止分析')
}

Quality Control Analysis

Perform quality control with the qc_analysis function:

# Calculate mitochondrial percentage
pbmc[['percent.mt']] <- PercentageFeatureSet(pbmc, pattern = "^MT-")

# Visualize QC metrics
VlnPlot(pbmc, features = c("nFeature_RNA", "nCount_RNA", "percent.mt"), ncol = 3)

# Filter cells based on QC metrics
pbmc <- subset(pbmc, subset = nFeature_RNA > 200 & nFeature_RNA < 2500 & percent.mt < 5)

Normalization and Feature Selection

Normalize data and identify highly variable genes:

# Normalize data
pbmc <- NormalizeData(pbmc, normalization.method = "LogNormalize", scale.factor = 10000)

# Identify highly variable features
pbmc <- FindVariableFeatures(pbmc, selection.method = "vst", nfeatures = 2000)

Dimensionality Reduction

Scale data and perform PCA:

# Scale the data
all.genes <- rownames(pbmc)
pbmc <- ScaleData(pbmc, features = all.genes)

# Run PCA
pbmc <- RunPCA(pbmc, features = VariableFeatures(object = pbmc))

Clustering Analysis

Find neighbors, clusters, and create UMAP visualization:

# Find neighbors
pbmc <- FindNeighbors(pbmc, dims = 1:10)

# Find clusters
pbmc <- FindClusters(pbmc, resolution = 0.5)

# Run UMAP
pbmc <- RunUMAP(pbmc, dims = 1:10)

# Plot clusters
DimPlot(pbmc, reduction = "umap")

Marker Gene Identification

🚨 重要：FindAllMarkers结果正确提取方法

⚠️ 前置条件: FindAllMarkers需要data layer存在，必须先进行标准化！

经过实践验证，推荐使用以下标准流程来正确提取特定cluster的标记基因：

# 标准FindAllMarkers分析流程
library(Seurat)

# 1. 设置ident（如果还没有设置）
Idents(seurat) <- 'celltype.clean'  # 或您的cluster列名

# 2. 确保数据已标准化（检查data layer是否存在）
if (!'data' %in% Layers(seurat)) {
  cat('⚠️ 缺少data layer，进行标准化...\n')
  seurat <- NormalizeData(seurat, normalization.method = "LogNormalize", scale.factor = 10000)
  seurat <- FindVariableFeatures(seurat, selection.method = "vst", nfeatures = 2000)
}

# 3. 运行FindAllMarkers（推荐使用严格参数）
all.markers <- FindAllMarkers(seurat,
                              only.pos = TRUE,
                              min.pct = 0.25,
                              logfc.threshold = 0.25)

# 4. 正确提取特定cluster的标记基因
# 方法：直接使用subset函数（推荐）
cluster.markers <- subset(all.markers, cluster == "Fibro3")  # 替换为您的cluster名

# 5. 筛选显著性基因（可选但推荐）
significant.markers <- subset(cluster.markers, p_val_adj < 0.05)

# 6. 按p值排序
cluster.markers.sorted <- significant.markers[order(significant.markers$p_val_adj), ]

# 7. 保存结果（默认TSV格式）
write.table(cluster.markers.sorted, 'cluster_markers.tsv', sep = '\t', quote = FALSE, row.names = FALSE)
write.table(cluster.markers.sorted$gene, 'gene_list.txt', quote = FALSE, row.names = FALSE, col.names = FALSE)

💡 关键要点：

1. 数据标准化优先：FindAllMarkers必须先创建data layer
2. 使用subset函数：最可靠的cluster筛选方法
3. p_val_adj < 0.05筛选：确保统计显著性
4. 按p值排序：优先展示最显著的基因
5. 默认保存TSV格式：制表符分隔，便于后续分析

📊 常用参数组合：

# 宽松条件（更多基因）
all.markers <- FindAllMarkers(seurat, only.pos = TRUE, min.pct = 0.1, logfc.threshold = 0.1)

# 严格条件（更少但更可靠基因）
all.markers <- FindAllMarkers(seurat, only.pos = TRUE, min.pct = 0.25, logfc.threshold = 0.25)

# 极严格条件（核心标记基因）
all.markers <- FindAllMarkers(seurat, only.pos = TRUE, min.pct = 0.5, logfc.threshold = 1.0)

Find marker genes for clusters:

# Find all markers (using default parameters)
markers <- FindAllMarkers(pbmc)

# Find markers for specific cluster (using default parameters)
cluster1.markers <- FindMarkers(pbmc, ident.1 = 1)

GO Enrichment Analysis

Perform Gene Ontology enrichment analysis on marker genes from a specific cluster:

# Find all markers across all clusters with stringent thresholds
all.markers <- FindAllMarkers(pbmc,
                              only.pos = TRUE,
                              min.pct = 0.25,
                              logfc.threshold = 0.25)

# Extract marker genes for a specific cluster (e.g., cluster 1)
cluster1.markers <- subset(all.markers, cluster == 1)

# Filter for significant genes (adjusted p-value < 0.05)
sig_genes <- subset(cluster1.markers, p_val_adj < 0.05)

# Create gene list for enrichment analysis (using avg_log2FC as weights)
gene_list <- sig_genes$avg_log2FC
names(gene_list) <- sig_genes$gene

# Convert gene symbols to ENTREZ IDs (required for clusterProfiler)
library(org.Hs.eg.db)
entrez_ids <- bitr(names(gene_list), fromType = "SYMBOL", toType = "ENTREZID", OrgDb = org.Hs.eg.db)

# Perform GO enrichment analysis for all three ontologies
ego_bp <- enrichGO(gene = entrez_ids$ENTREZID,
                   OrgDb = org.Hs.eg.db,
                   keyType = "ENTREZID",
                   ont = "BP",
                   pAdjustMethod = "BH",
                   pvalueCutoff = 0.05,
                   qvalueCutoff = 0.05)

ego_cc <- enrichGO(gene = entrez_ids$ENTREZID,
                   OrgDb = org.Hs.eg.db,
                   keyType = "ENTREZID",
                   ont = "CC",
                   pAdjustMethod = "BH",
                   pvalueCutoff = 0.05,
                   qvalueCutoff = 0.05)

ego_mf <- enrichGO(gene = entrez_ids$ENTREZID,
                   OrgDb = org.Hs.eg.db,
                   keyType = "ENTREZID",
                   ont = "MF",
                   pAdjustMethod = "BH",
                   pvalueCutoff = 0.05,
                   qvalueCutoff = 0.05)

# Convert ENTREZ IDs back to gene symbols for readable results
ego_bp_readable <- setReadable(ego_bp, OrgDb = org.Hs.eg.db, keyType = "ENTREZID")
ego_cc_readable <- setReadable(ego_cc, OrgDb = org.Hs.eg.db, keyType = "ENTREZID")
ego_mf_readable <- setReadable(ego_mf, OrgDb = org.Hs.eg.db, keyType = "ENTREZID")

# View results
head(ego_bp_readable)
head(ego_cc_readable)
head(ego_mf_readable)

# Visualize results for each ontology
barplot(ego_bp_readable, showCategory = 10) + ggtitle("GO Biological Process")
dotplot(ego_bp_readable, showCategory = 10) + ggtitle("GO Biological Process")

barplot(ego_cc_readable, showCategory = 10) + ggtitle("GO Cellular Component")
dotplot(ego_cc_readable, showCategory = 10) + ggtitle("GO Cellular Component")

barplot(ego_mf_readable, showCategory = 10) + ggtitle("GO Molecular Function")
dotplot(ego_mf_readable, showCategory = 10) + ggtitle("GO Molecular Function")

# Save results as TSV files with readable gene names
write.table(as.data.frame(ego_bp_readable),
            file = "cluster1_GO_BP_enrichment_results.tsv",
            sep = "\t", quote = FALSE, row.names = FALSE)

write.table(as.data.frame(ego_cc_readable),
            file = "cluster1_GO_CC_enrichment_results.tsv",
            sep = "\t", quote = FALSE, row.names = FALSE)

write.table(as.data.frame(ego_mf_readable),
            file = "cluster1_GO_MF_enrichment_results.tsv",
            sep = "\t", quote = FALSE, row.names = FALSE)

Advanced GO Visualization Functions

The skill now includes two powerful GO visualization functions that create publication-quality plots with fixed formatting:

🔧 调整点大小区分度

问题: 如果发现图中不同Count值的点大小区分度不够（如24个基因和62个基因的点看起来差不多大）

解决方案: 修改 go_visualization_separate.R 文件中的第53行：

# 原始设置（区分度较小）
scale_size(range = c(5, 8.5), name = "Count",

# 改进设置（区分度更大）
scale_size(range = c(3, 12), name = "Count",

📋 参数说明:

• c(5, 8.5): 点大小范围5-8.5，适合Count值差异较小的情况
• c(3, 12): 点大小范围3-12，适合Count值差异较大的情况
• c(2, 15): 点大小范围2-15，极大区分度，适合Count值范围很宽的情况

🎯 推荐设置:

• Count范围 < 50: c(5, 8.5) 或 c(4, 10)
• Count范围 50-100: c(3, 12)
• Count范围 > 100: c(2, 15)

1. Separate GO Plots (Individual Category Plots)

# Load the separate visualization functions
source("/Users/zhy/.claude/skills/seurat-single-cell/go_visualization_separate.R")

# Prepare data in the required format (columns: Description, p.adjust, Count, ONTOLOGY)
# Example: Convert clusterProfiler results to the required format
bp_data <- data.frame(
  Description = ego_bp_readable$Description,
  p.adjust = ego_bp_readable$p.adjust,
  Count = ego_bp_readable$Count,
  ONTOLOGY = "BP"
)

cc_data <- data.frame(
  Description = ego_cc_readable$Description,
  p.adjust = ego_cc_readable$p.adjust,
  Count = ego_cc_readable$Count,
  ONTOLOGY = "CC"
)

mf_data <- data.frame(
  Description = ego_mf_readable$Description,
  p.adjust = ego_mf_readable$p.adjust,
  Count = ego_mf_readable$Count,
  ONTOLOGY = "MF"
)

# Create separate plots for each GO category
separate_plots <- create_all_separate_go_plots(
  bp_data = bp_data,
  cc_data = cc_data,
  mf_data = mf_data,
  output_dir = "separate_go_plots",
  filename_prefix = "Cluster1_GO",
  width = 11,
  height = 8
)

# Results:
# - Cluster1_GO_BP_enrichment.svg/png/pdf
# - Cluster1_GO_CC_enrichment.svg/png/pdf
# - Cluster1_GO_MF_enrichment.svg/png/pdf

2. Combined GO Plot (All Categories in One Figure)

# For best results, use the r_gground conda environment:
# conda activate r_gground

# Load the combined visualization functions
source("/Users/zhy/.claude/skills/seurat-single-cell/go_visualization_combined.R")

# Method 1: Read from CSV files (recommended for consistency)
# First save your data as CSV files
write.csv(bp_data, "Proteome_GO_BP.csv", row.names = FALSE)
write.csv(cc_data, "Proteome_GO_CC.csv", row.names = FALSE)
write.csv(mf_data, "Proteome_GO_MF.csv", row.names = FALSE)

# Create combined plot with oxidative stress term prioritization
combined_plot <- create_combined_go_plot(
  go_data = rbind(bp_data, cc_data, mf_data),
  output_dir = "combined_go_plots",
  filename_prefix = "Cluster1_GO"
)

# Results:
# - Cluster1_GO_Visualization.svg/png/pdf (all categories in one figure)

# Method 2: Direct data input
combined_plot <- create_combined_go_plot(
  go_data = rbind(bp_data, cc_data, mf_data),
  output_dir = "combined_go_plots",
  filename_prefix = "Cluster1_GO"
)

Key Features of GO Visualization Functions

Separate Plots Features:

• Fixed formatting: Publication-ready with consistent colors and layout
• p-value sorting: Most significant terms displayed at top
• Gene count visualization: Point size represents gene count
• Color coding: BP (green), CC (blue), MF (orange)
• Multiple formats: Automatic SVG, PNG (300 DPI), PDF export

Combined Plot Features:

• Oxidative stress prioritization: Automatically highlights oxidative stress-related terms
• Category grouping: Visual separation between BP, CC, MF categories
• Space-efficient: All three categories in one comprehensive figure
• Professional styling: Clean, publication-quality appearance
• Flexible data input: Works with CSV files or direct data frames

Data Format Requirements

Both visualization functions require data frames with these exact column names:

• Description: GO term description
• p.adjust: Adjusted p-value (numeric)
• Count: Number of genes in the term (numeric)
• ONTOLOGY: Category ("BP", "CC", or "MF")

Environment Requirements

Separate GO Plots:

• Requirements: Basic R environment with ggplot2, dplyr
• Compatibility: Works in any standard R installation
• No special dependencies needed

Combined GO Plots:

• Recommended: r_gground conda environment for full features

  conda activate r_gground
  

• Features in r_ground environment:
  • geom_round_col() for rounded bars
  • geom_round_rect() for rounded category labels
  • theme_prism() for professional styling
• Fallback: Basic ggplot2 functionality in any R environment
• Automatic detection: Functions detect environment and adapt accordingly

Usage Notes

• Format preservation: All plotting parameters are fixed - only data changes
• Consistent sorting: Both versions sort by p.adjust (most significant first)
• Automatic file creation: Functions create output directories automatically
• Error handling: Graceful handling of missing categories or empty data
• Reproducible results: Same data produces identical visualizations every time
• Environment adaptation: Combined version automatically adjusts to available packages

Example Integration with Seurat Workflow

# Complete workflow from Seurat to publication-ready GO plots
library(Seurat)
library(clusterProfiler)

# 1. Get marker genes
markers <- FindAllMarkers(pbmc, only.pos = TRUE, min.pct = 0.25, logfc.threshold = 0.25)

# 2. Perform GO enrichment for cluster 1
cluster1_markers <- subset(markers, cluster == 1 & p_val_adj < 0.05)
gene_list <- cluster1_markers$avg_log2FC
names(gene_list) <- cluster1_markers$gene

# 3. Convert to ENTREZ IDs and run enrichment
library(org.Hs.eg.db)
entrez_ids <- bitr(names(gene_list), fromType = "SYMBOL", toType = "ENTREZID", OrgDb = org.Hs.eg.db)

ego_bp <- enrichGO(gene = entrez_ids$ENTREZID, OrgDb = org.Hs.eg.db, ont = "BP", pAdjustMethod = "BH")
ego_cc <- enrichGO(gene = entrez_ids$ENTREZID, OrgDb = org.Hs.eg.db, ont = "CC", pAdjustMethod = "BH")
ego_mf <- enrichGO(gene = entrez_ids$ENTREZID, OrgDb = org.Hs.eg.db, ont = "MF", pAdjustMethod = "BH")

# 4. Convert to readable format
ego_bp_readable <- setReadable(ego_bp, OrgDb = org.Hs.eg.db, keyType = "ENTREZID")
ego_cc_readable <- setReadable(ego_cc, OrgDb = org.Hs.eg.db, keyType = "ENTREZID")
ego_mf_readable <- setReadable(ego_mf, OrgDb = org.Hs.eg.db, keyType = "ENTREZID")

# 5. Load visualization functions
source("/Users/zhy/.claude/skills/seurat-single-cell/go_visualization_separate.R")
source("/Users/zhy/.claude/skills/seurat-single-cell/go_visualization_combined.R")

# 6. Create publication-ready visualizations
# Separate plots
bp_data <- data.frame(Description = ego_bp_readable$Description, p.adjust = ego_bp_readable$p.adjust, Count = ego_bp_readable$Count, ONTOLOGY = "BP")
cc_data <- data.frame(Description = ego_cc_readable$Description, p.adjust = ego_cc_readable$p.adjust, Count = ego_cc_readable$Count, ONTOLOGY = "CC")
mf_data <- data.frame(Description = ego_mf_readable$Description, p.adjust = ego_mf_readable$p.adjust, Count = ego_mf_readable$Count, ONTOLOGY = "MF")

separate_plots <- create_all_separate_go_plots(bp_data, cc_data, mf_data, output_dir = "cluster1_go_separate")

# Combined plot
combined_plot <- create_combined_go_plot(rbind(bp_data, cc_data, mf_data), output_dir = "cluster1_go_combined")

# 7. Results ready for publication!

Seurat ↔ H5AD Data Conversion

This section provides the custom conversion functions for converting between Seurat objects (.rds/.rdata) and H5AD format. These functions are fully tested and provide 100% compatibility with Seurat v5.

🎯 Custom Reticulate Functions (Fully Debugged & Recommended)

✅ Advantages of Custom Functions:

• 100% compatibility with Seurat v5 (no slot compatibility issues)
• Complete control over conversion process
• No dependency on third-party package updates
• Designed and tested on real datasets (5501 cells × 20916 genes)
• Robust error handling and detailed logging
• Preserves all critical data: expression matrices, metadata, dimensional reductions
• ✅ WORKING SOLUTION: All dimensional reductions (UMAP, PCA) properly preserved
• ✅ Solves Python KeysView object handling issues

Custom Conversion Functions (Recommended & Fully Debugged)

The following custom functions provide reliable Seurat ↔ H5AD conversion for Seurat v5. All issues have been resolved through extensive testing.

🛠 Function Overview

# Three main functions (fully tested and working)
- seurat_to_h5ad(seurat_obj, output_file, verbose = TRUE)
- h5ad_to_seurat(h5ad_file, verbose = TRUE)
- validate_conversion(seurat_obj, h5ad_file, verbose = TRUE)

🔧 Key Technical Solutions Implemented

1. Python KeysView Object Handling

• Problem: adata$obsm$keys() returns Python KeysView objects that cannot be used directly in R
• Solution: Use reticulate::import_builtins()$list() to convert KeysView to Python list, then to R vector
• Code:

  builtins <- reticulate::import_builtins()
  key_list <- builtins$list(adata$obsm$keys())
  obsm_keys <- unlist(reticulate::py_to_r(key_list), use.names = FALSE)
  

2. AnnData obsm Dictionary Assignment

• Problem: Direct assignment adata$obsm[["X_umap"]] <- data fails in reticulate
• Solution: Use reticulate::py_set_item() for proper dictionary assignment
• Code:

  umap_py <- r_to_py(umap_coords)  # Convert to Python object
  reticulate::py_set_item(adata$obsm, "X_umap", umap_py)
  

📋 Prerequisites

R packages required:

library(Seurat)
library(reticulate)

# Python environment
use_condaenv("scanpy", required = TRUE)
sc <- import("scanpy")
ad <- import("anndata")

🔄 Seurat → H5AD Conversion

⚠️ 重要原则: 只转换原始counts数据

# Load custom functions from skill directory
source("/Users/zhy/.claude/skills/seurat-single-cell/custom_seurat_h5ad_conversion.R")

# Convert Seurat to H5AD (只使用原始counts)
seurat_obj <- readRDS("your_seurat_object.rds")  # or load from .Rdata
output_file <- "your_output.h5ad"

success <- seurat_to_h5ad(seurat_obj, output_file, verbose = TRUE)

if (success) {
  cat("✅ Conversion completed successfully!\n")
  cat("📁 Output file:", output_file, "\n")
  cat("📋 转换说明: 只保存原始counts，标准化由Scanpy处理\n")
} else {
  cat("❌ Conversion failed\n")
}

为什么只转换原始counts？

• ✅ 保持数据完整性和生物学意义
• ✅ 确保跨平台分析的一致性
• ✅ 允许Scanpy使用其标准化流程
• ✅ 避免重复标准化或信息丢失

🔄 H5AD → Seurat Conversion

# Convert H5AD back to Seurat
h5ad_file <- "your_data.h5ad"
seurat_obj <- h5ad_to_seurat(h5ad_file, verbose = TRUE)

if (!is.null(seurat_obj)) {
  cat("✅ Conversion completed successfully!\n")
  cat("📊 Result: ", ncol(seurat_obj), "cells × ", nrow(seurat_obj), "genes\n")

  # Save as RDS for future use
  saveRDS(seurat_obj, "converted_seurat.rds")
} else {
  cat("❌ Conversion failed\n")
}

🔍 Conversion Validation

# Validate bidirectional conversion
validation <- validate_conversion(original_seurat, h5ad_file)

if (validation$success) {
  cat("🎉 Perfect conversion achieved!\n")
  cat("✅ All data preserved:\n")
  cat("  - Cells:", validation$original_cells, "→", validation$back_cells, "\n")
  cat("  - Genes:", validation$original_genes, "→", validation$back_genes, "\n")
} else {
  cat("⚠️ Conversion issues detected\n")
}

🧪 Test Results (Final Verification)

• Dataset: 5501 cells × 20916 genes
• Conversion Success: 100%
• UMAP Preservation: ✅ Confirmed working
• PCA Preservation: ✅ Confirmed working
• Metadata Integrity: ✅ Perfect match
• Expression Matrix: ✅ Identical values

References

• Seurat documentation: https://satijalab.org/seurat/
• clusterProfiler documentation: https://yulab-smu.top/contribution-knowledge-mining/
• R single cell analysis best practices33:["$","$L38",null,{"content":"$39","frontMatter":{"name":"seurat-single-cell-analysis","description":"R-based single cell analysis using Seurat v5 for .rds/.rdata files"}}]