Scientists Discover Gene Critical For Embryo Survival After Fertilization

Scientists in Singapore have discovered a key protein that is important for the survival of the embryo immediately after fertilization has occurred in the mother’s egg.

AsianScientist (Apr. 2, 2012) – Scientists in Singapore have discovered a key protein that is important for the survival of the embryo immediately after fertilization has occurred in the mother’s egg.

The study, published in the journal Science, reports a novel protein called TRIM28 as the linking factor which regulates two critical developmental processes during the early embryonic phase.

These two processes, nuclear reprogramming and genomic imprinting, are critical for embryo survival after egg fertilization, the latter being first described by Dr. Davor Solter, a co-author of the paper.

Upon fertilization, nuclear reprogramming erases most of the ‘epigenetic marks’ in both paternal and maternal DNA. This ‘reset’ program allows early embryonic cells to develop into different cell types.

At the same time, there are specific epigenetic marks from the mother and father that cannot be erased, and hence the embryo inherits these marks in order to survive and develop. This phenomenon is termed genomic imprinting.

The story of the TRIM gene starts with an intriguing finding that researchers from the A*STAR Institute of Medical Biology observed in genetically identical mice lacking the TRIM gene.

Instead of exhibiting similar defects due to the absence of the same gene, TRIM-deficient mice showed different abnormalities in development and died at varying stages.

This prompted a further collaboration with Dr. Anne Ferguson-Smith from the Cambridge University, who studied TRIM expression levels using microarray and biochemical studies.

Ferguson-Smith showed that the TRIM gene is not only critical for the survival at early embryo stage, but its timing and expression levels also affected imprinted genes at later stages of embryonic development.

“We now know TRIM28 instructs the ‘cleaning lady’ which part of the formulas she should preserve,” Solter explained.

The results of this study have also raised many valuable insights into infertility treatment in women.

“Lack of TRIM28 in their eggs could explain why some women consistently suffer from multiple failed pregnancies where embryos die at different time points, manifesting multiple, different abnormalities,” said Dr. Barbara Knowles, a senior co-author.

The article can be found at: Messerschmidt DM et al. (2012) Trim28 Is Required for Epigenetic Stability During Mouse Oocyte to Embryo Transition.

——

Source: A*STAR.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

Yuka graduated with a BSc (Hons) in life sciences from the National University of Singapore (NUS), Singapore, and received her MSc in cancer biology at University College London, UK.

Related Stories from Asian Scientist