In order to investigate the basic stable methylation pattern in rat somatic cells, we analyzed the methylation status of both loci by bisulfite sequencing.
Based on previous studies showing that fusion of ESCs with somatic cells induce nuclear reprogramming [23], [24], [25], we hypothesized that introduction of ESC total proteins into rat somatic cells may reprogram them to a pluripotency.
The rat cytochrome c comes in two forms, one found in somatic cells, rat(s), and the other found exclusively in sperm cells, rat(t), and only expressed during spermatogenesis.
This approach has now been used to establish facile and efficient reverse genetics (that is, reverse genetics that does not require selection) in Drosophila melanogaster, zebrafish, rats, Arabidopsis thaliana and mammalian somatic cells.
SUMO-1 has also been localized in male germ cells and somatic cells of mouse and rat testes [19] as well as in human male germ and somatic cells [20].
TALENs are novel engineered nucleases for gene disruption and have been successfully applied in a variety of organisms and cell types including plant [ 14], Drosophila[ 10], C. elegans[ 13], zebrafish [ 9, 11], Xenopus[ 4, 5], rat [ 12], livestock [ 6], human somatic cells [ 7], and human pluripotent stem cells [ 8].
CpG islands are selectively associated with the regulatory regions of L1 elements and are generally methylated in somatic cells of humans and rats.
Leukocytes from adult women (Jeanclos et al., 2000; Benetos et al., 2001; Nawrot et al., 2004) and somatic cells from adult female rats (Cherif et al., 2003) had significantly longer telomeres than the corresponding male cells.
We asked whether the reprogramming potential of Nanog /– somatic cells could be restored by rat Nanog (rNanog) or human Nanog (hNanog) (Fig. 1A, supplementary material Fig. S1B).
There was no/little detectable 5mC in germ cells between e14.5 and e18.5, suggesting that, as in mice, rat germ cells are hypomethylated relative to surrounding somatic cells by e14.5.
Thus, the stable presence of 5hmC, 5fC and 5caC in rat germ cells between e14.5 and e16.5, and in testicular somatic cells throughout late gestation, may indicate potential functionality of these modifications during germ cell development.
