Molecular mechanisms of cell specification
Germ cells take their name from the fact that they are like the seed from which a plant germinates or develops. Primordial germ cells (PGCs) give rise to the sperm and the egg in many species, including our own. Thus, they are critical to transmitting genetic information in multicellular organisms. Given that the PGCs give rise to a specific type of cells (gametes critical to reproduction), they are considered unipotent. However, with the process of fertilisation, the resulting cell then generates cells capable of differentiating into skin cells, bone cells and all the other cells of the organism, making the fertilised egg totipotent. During embryonic development, subsets of cells become pluripotent, or capable of differentiating into numerous cell types but not an entire organism. Embryonic germ cells are derived from PGCs and are thought to have properties similar to embryonic stem cells. Thus, studies of PGCs and the mechanisms for differentiation and specification of function have widespread application to the use of stem cells for generating other types of cells whose function is compromised due to disease or trauma. The ‘Molecular mechanism for primordial germ cell specification - the role of Blimp1’ (BLIMP1 IN PGCs) project was designed to evaluate the transcription factor Blimp1 and, specifically, the molecular mechanism of its action in PGC specification to pluripotency. Activities included first generating DNA binding profiles for Blimp1 over the entire genome in the context of pluripotent cells. Gene expression studies were then carried out to assess the effects of Blimp1 binding to DNA. The results pointed to specific primary and secondary events that occur downstream of Blimp1 (or after Blimp1 binding to DNA). Finally, the binding profiles of Blimp1 were compared to those of other factors known to be involved in development of pluripotency, elucidating potential mechanisms by which Blimp1 acts in conjunction with other factors in producing PGC specification. The results of the project provide important insight into gene expression mechanisms of Blimp1 during PGC specification. The findings could have far-reaching impact on both stem cell research and gene-related therapies for diseased or damaged tissue.