Klement et al., "Imprinted Igf2r
silencing depends on continuous Airn lncRNA expression and is not restricted to a developmental window," Development, vol.
The Roslin Institute's Lorraine Young and her colleagues examined the activity of the IGF2R
gene in sheep fetuses created through IVF, which like cloning often results in large-offspring syndrome in sheep.
The researchers found that humans and other primates are born with 2 activated copies of the IGF2R
gene, or insulin-like growth factor II receptor.
is only one of many genes that contribute to intelligence, and there are other factors to take into account.
The highly expressed growth factor receptor genes, meanwhile, were platelet-derived growth factor receptor-like protein, platelet-derived growth factor receptor (beta polypeptide), autocrine motility factor receptor, transforming growth factor beta type 2 receptor, epidermal growth factor receptor, and insulin-like growth factor 2 receptor (IGF2R
The 2 most commonly affected genes are human Mu1L homolog-1 (hMLHl) and human mutS homolog-2 (hMSH2), but other genes are also affected, such as those prone to incorrect copying because of short nucleotide repeats, including transforming growth factor, [beta] receptor II (TGFBR2), insulin-like growth factor 2 receptor (IGF2R
), and Bcl-2-associated X protein (BAX).
repression does not correlate with expression of antisense RNA in human extraembryonic tissues.
A DNA marker inserted into the gene for insulinlike growth factor-2 receptor (IGF2R
) on chromosome 6 revealed that one form of the gene occurs more frequently in a group of 51 high-intelligence children, with an average IQ of 136, than in 51 youngsters with more modest scores, averaging 103.
Of the 15 maternally methylated germline ICRs, four (IGF2R
, KvDMR, SNURF/SNRPN, GNASXL) overlapped Cd-associated DMRs in newborn cord blood, nine (SNURF/SNRPN, GNASXL, PEG3, MCTS2, NNAT, GNAS, PLAGL1, GRB10, PEG13) overlapped DMRs in maternal blood, and four did not overlap with DMRs in either newborn cord blood or maternal blood (Figure 2A).
Generation of five human lactoferrin transgenic cloned goats using fibroblast cells and their methylation status ofputative differential methylation regions of IGF2R
and H19 imprinted genes.
Several cMS-containing genes that encode proteins involved in the regulation of cell growth (TGFBRII and IGF2R
) (13, 14), programmed cell death (BAX and caspase-5) (15, 16), DNA-mismatch repair (hMSH3 and hMSH6) (17), transcription (TCF4) (18), or protein translocation (SEC63) (19) are frequently mutated in MSI cancers.
The family consists of two ligands (IGF1 and IGF2), two receptors (IGF1R and IGF2R
), and six binding proteins (insulin-like growth factor binding protein [IGFBP1 to IGFBP6])(Annunziata et al., 2011).