Novel Haploid Stem Cells Expected to Advance Genomics Research

A team of cell biologists has generated a novel type of haploid pluripotent embryonic stem cells that have only one set of chromosomes instead of the usual two.

It is expected that haploid human embryonic stem cells will provide a novel means for studying human functional genomics and development. The only natural occurring haploid human cells are the gametes, which are not pluripotent. Previous attempts to use human gametes to generate stem cells resulted in cells that were all diploid.

Investigators at The Hebrew University of Jerusalem (Israel) and colleagues at Columbia University (New York, NY, USA) and The New York Stem Cell Foundation Research Institute (NY, USA) recently described a method for generating haploid embryonic stem cells.

The method, which was published in the March 16, 2016, online edition of the journal Nature, was based on inducing the division of unfertilized human egg cells followed by the isolation and maintenance of a subset of cells that were haploid.

These haploid stem cells exhibited typical pluripotent stem cell characteristics, such as self-renewal capacity and a pluripotency-specific molecular signature. Moreover, these cells demonstrated considerable utility as a platform for loss-of-function genetic screening. Although haploid human stem cells resembled their diploid counterparts, they also displayed distinct properties including differential regulation of X chromosome inactivation and of genes involved in oxidative phosphorylation, alongside reduction in absolute gene expression levels and cell size.

"This study has given us a new type of human stem cell that will have an important impact on human genetic and medical research," said senior author Dr. Nissim Benvenisty, professor of genetics at The Hebrew University of Jerusalem. "These cells will provide researchers with a novel tool for improving our understanding of human development, and the reasons why we reproduce sexually, instead of from a single parent."

"This work is an outstanding example of how collaborations between different institutions, on different continents, can solve fundamental problems in biomedicine," said contributing author Dr. Dieter Egli, assistant professor of developmental cell biology in pediatrics at Columbia University.

Related Links:
The Hebrew University of Jerusalem
Columbia University
The New York Stem Cell Foundation Research Institute