Protocols for cytogenetic studies of human embryonic stem cells

Area of Science:

• Stem Cell Biology
• Cytogenetics
• Genetics

Background:

• Cultured cells, including human embryonic stem cells (hESC), accumulate chromosome changes over time.
• Adaptive chromosome changes, specifically trisomy 12 and trisomy 17, are common in hESC cultures and allow cells to survive.
• Cells with trisomies are phenotypically similar to normal cells and express pluripotency markers, complicating identification without specialized analysis.

Purpose of the Study:

• To highlight the importance of early detection of chromosome abnormalities in hESC cultures.
• To describe cytogenetic methods for identifying trisomy 12 and trisomy 17 in hESCs.
• To recommend integrating cytogenetic analysis into routine hESC quality control.

Main Methods:

• G-banding: The gold standard for detecting chromosome abnormalities.
• Interphase FISH (Fluorescence In Situ Hybridization): A sensitive method for detecting cytogenetic aberrations.
• Combined G-banding and FISH: Provides a sensitive approach for early detection of full and partial trisomies of chromosomes 12 and 17.

Main Results:

• Trisomy 12 and trisomy 17 are the most frequent chromosome changes observed in hESC cultures.
• Cells with trisomies 12 and 17 can outcompete normal cells within 5-10 passages.
• Cytogenetic analysis, particularly G-banding combined with interphase FISH, is effective for early detection.

Conclusions:

• Early detection of trisomy 12 and 17 in hESC cultures is critical to maintain genetic integrity.
• Cytogenetic analysis is essential for quality control of hESC lines.
• Implementing routine cytogenetic analysis, including G-banding and FISH, is recommended for hESC culture monitoring.