High impact information on IGF2

• We found that, similar to the human and mouse, bovine IGF2 is subjected to extensive transcriptional regulation through multiple promoters, alternative splicing and polyadenylation, as well as genetic imprinting [1].
• In the present study, we obtained virtually the entire sequence of the bovine IGF2 cDNA, identified expressed single-nucleotide polymorphisms (SNPs) in both exons 3 and 10, and determined the age-, tissue-, and promoter-specific expression of bovine IGF2 in fetal, calf, and adult tissues [1].
• The product of the insulin-like growth factor 2 (IGF2) gene is one of the most important fetal mitogens known to date [1].
• Expression patterns of parental alleles in F1 hybrids indicated preferential paternal expression at the XIST locus solely in the chorion of females, whereas analysis of the IGF2 and GTL2 loci indicated preferential paternal and maternal expression of alleles, respectively, in both fetal and placental tissues [2].
• This polymorphism was used to map IGF2 to sheep Chromosome (Chr) 21 and demonstrate that IGF2 is indeed imprinted in sheep, being expressed from the paternal allele [3].

Biological context of IGF2

• Genomic imprinting of the insulin-like growth factor 2 gene in sheep [3].
• Coding single nucleotide polymorphisms (SNPs) between Bos gaurus and Bos taurus were detected at the XIST, IGF2, and GTL2 loci, which have previously been identified as imprinted in either humans, mice, or sheep [2].
• Cryosections were incubated with [125I]-IGF alone or with unlabeled IGF-1, IGF-2, or insulin to characterize binding sites as probable Type 1 IGF, Type 2 IGF, or insulin receptors [4].
• At necropsy on day 78 or day 135 of gestation, gravid uteri were recovered. mRNA expression of IGF-1 and IGF-2 in ventricles were measured with RT-PCR, and protein expression of IGF-1R, IGF-2R, IGFBP-3 was quantitated with Western blot [5].
• No difference was found in IGF-1, IGF-2 or IGFBP-3 levels between the NR and C groups at either gestational age [5].

Anatomical context of IGF2

• The mean IGF-2 activity was 2349 +/- 83 ng/ml (n = 7) in the sham operated fetuses and 3800 +/- 532 ng/ml in the pancreatectomized animals (n = 13) [6].

Associations of IGF2 with chemical compounds

• One of the first imprinted genes identified was the Insulin-like Growth Factor 2 gene (IGF2), which promotes growth of the fetus and is expressed from only the paternal allele in most tissues in both the mouse and human [3].
• Secretion of progesterone by CL of 88-90 days of pregnancy was not affected by IGF1, IGF2, PAF-16, PAF-18, oxytocin, PGI2, PGD2 or leukotriene C4 (P > or = 0.05) [7].
• Plasma IGF-2 activity was correlated positively with plasma glucose, fructose and alpha-amino nitrogen levels and inversely related to the plasma insulin concentration in utero [6].

Analytical, diagnostic and therapeutic context of IGF2

• Fetal pancreatectomy reduced significantly the plasma IGF-1 concentration and increased plasma IGF-2 activity in comparison with the values observed in sham operated fetuses [6].

References