Evaluating histone modification analysis of individual preimplantation embryos

Area of Science:

• Epigenetics
• Developmental Biology
• Genomics

Background:

• Previous work established NTU-CAT for genome-wide histone modification analysis in single preimplantation embryos.
• The current study simplified NTU-CAT using the Well-of-the-Well (WOW) system, creating WOW-CUT&Tag (WOW-CAT).

Purpose of the Study:

• To simplify and improve the efficiency of single-embryo histone modification analysis.
• To enable flexible epigenetic profiling for preimplantation genetic diagnosis.

Main Methods:

• Utilized the Well-of-the-Well (WOW) system for processing multiple embryos simultaneously.
• Applied WOW-CUT&Tag (WOW-CAT) for genome-wide histone modification profiling from single blastocysts or portions thereof.
• Performed simultaneous analysis of two histone modifications (H3K4me3 and H3K27ac) within the same embryo.

Main Results:

• WOW-CAT enabled histone modification profiling from single blastocysts and even partial blastocysts.
• WOW-CAT yielded H3K4me3 profiles comparable to NTU-CAT but closer to ChIP-sequencing standards, with reduced false positives.
• Demonstrated simultaneous analysis of H3K4me3 and H3K27ac in halves of the same embryo.
• Successfully applied WOW-CAT to biopsied trophectoderm cells for preimplantation epigenetic diagnosis, including embryo sexing via H3K4me3 analysis of XIST and DDX3Y without deep sequencing.

Conclusions:

• WOW-CAT offers a simplified, efficient, and flexible method for epigenetic analysis of individual embryos.
• The technique is applicable for preimplantation epigenetic diagnosis, including non-invasive embryo sexing.