Previous work reported that excess nitrogen sources had been implicated in the repression of secondary metabolism such as penicillin biosynthesis in Penicillium sp. (Sanchez et al. [1981]).
It was therefore important to establish which of these combinations might be implicated in the repression of INK4a in human fibroblasts.
On the other hand, type II arginine methyltransferase, PRMT5, has been implicated in the repression of genes leading to differentiation of different cell types at early stages of development.
Since miRNAs have been implicated in the repression of gene expression, we speculated that miR-18a might target a negative regulator of the STAT3 signalling pathway.
Therefore, Prdm14 appears to be implicated in the repression of DNA methylation in the germline, which in turn may allow for the expression of germline genes [ 11], such as Dazl, Tex19.1, Rhox9 and Sycp3.
Furthermore, in a recent study, the E z) homolog, EZH, in the green algae Chlamydomonas reinhardtii, has been implicated in the repression of both (hetero euchromatic transgenes and dispersed retrotransposons.
These proteins are implicated in the transcriptional repression of methylated DNA [ 4, 5].
More recently, genome-wide ChIP analyses have identified over 1000 genes that are potential targets of PcG-mediated repression, many of which are implicated in the maintenance of pluripotency [16] [18].
Notably, other oncogenic factors, such as ID-1 and BMI-1, have previously been implicated in the transcriptional repression of p16, as well as other members of the polycomb group of transcription factors.
