Researchers have recently discovered an overlooked cellular process present within the inner cell mass of the early embryo. This discovery illuminates a mechanism that discreetly eradicates unsuitable cells before birth. The main figure in this finding is the gene Human endogenous retrovirus subfamily H (HERVH). This gene plays a pivotal role in deciding the destiny of cells during embryonic development.
The Inner Cell Mass and its Function
During the initial stages of embryonic development, cells gather themselves into a key structure known as the inner cell mass. This mass encompasses pluripotent cells, which possess the ability to form any cell type within the human body.
In 2016, a fascinating revelation was made while researchers were examining gene expression data from early human embryos. They discovered a collection of non-committed cells (those that would not become part of the later stages of the embryo) within the inner cell mass. These cells experience early elimination. While most cells within the inner cell mass express HERVH – a gene vital for maintaining pluripotency, these specific non-committed cells, destined for disposal, do not showcase HERVH expression.
The Impact of HERVH on Cell Fate
The lack of HERVH in non-committed cells unveiled a surprising link to “jumping genes” or transposons. These dangerous elements of Deoxyribonucleic Acid (DNA) can embed themselves in varying regions of the genome, inflicting damage and leading to cell death. HERVH serves as a protective shield for cells against these transposons. It guards from DNA harm and certifies the survival of cells committed to forming the developing embryo.
The Circle of Life and Death in Cell
Cells expressing HERVH survive and contribute to the formation of the embryo. In comparison, the non-committed cells undergo a process of elimination, resulting in cell death.
It’s interesting to note that the cells which form the placenta also demonstrate transposon activity – however, they do not express HERVH. Despite this, these specific cells exhibit a higher tolerance towards transposons, thereby avoiding cell death. Unlike other fetal cells, the placenta is unique as it gets discarded post-childbirth.
Implications of HERVH’s Role and its Future Application
The involvement of HERVH in pluripotency presents significant implications for regenerative medicine and opens up potential pathways for stem cell research. Researchers are considering the possibility that diminishing transposon activity in early embryos could have an impact on fitness. This speculation could influence treatments for infertility and methods of in vitro fertilization.
A recent UPSC Civil Services Examination contained a question regarding the latest developments in science. It challenged the candidate’s understanding of DNA replication in both living cells and laboratory settings. Notably, advancements have been made in developing semi-synthetic strains of bacteria that incorporate both natural and artificial DNA. This breakthrough has the potential to create entirely new, synthetic proteins. Furthermore, a wide array of double-stranded DNA templates can now be replicated extensively in an in-vitro DNA replication system containing purified proteins. In addition, through micro-propagation, plants can be developed in a laboratory. Therefore, the study of cellular processes continues to have far-reaching effects on diverse aspects of science and medicine.
