A screening method using cultured, differentiated mouse embryonic stem (ES) cells has identified Lin28 as an important gene in the formation of germ cells -- progenitors of egg and sperm cells. The study, reported in Nature, highlights the use of cultured stem cells for determining key genes involved in important biological processes, such as the development of egg and sperm, and cancer.
George Daley and colleagues differentiated mouse ES cells into putative primordial germ cells, the early embryonic precursors of egg and sperm. They then used short inhibitory RNA strands to switch off key genes, a technique that highlighted Lin28 as a possible player in germ-cell formation.
To confirm their suspicions, ES cells lacking Lin28 were injected into developing mouse embryos where they then failed to form germ cells in the chimaeric animals. Overexpressing Lin28, by contrast, enhanced the formation of germ cells in chimaeric animals. The team also showed that Lin28 levels are raised in primary human germ-cell tumours. Overall, the study suggests that Lin28 is a novel regulator of germ-cell development and a possible player in germ-cell malignancy.
George Daley (Children's Hospital Boston, Massachusetts, USA)
Abstract available online.
(C) Nature press release.
Message posted by: Trevor M. D'Souza