Localization of insulin-like growth factor genes to human chromosomes 11 and 12

The insulin-like growth factors IGF-I and IGF-II are required for growth and development. Both are single-chain proteins (of 70 and 67 amino acids respectively) derived from precursors by proteolytic processing. IGF-I may be particularly important in promoting normal stature and IGF-II may be a fetal growth hormone. The IGF proteins are probably synthesized by many normal tissues and by some tumours. The secretion of growth factors by tumours and tumour-derived cell lines suggests that they may act as autocrine regulators of cell proliferation. Because of the possible role of these proteins in growth disorders and cancer, and their sequence homology with insulin, we have determined their chromosomal localization. Using somatic cell hybrids and cloned cDNA probes for these proteins, we have assigned the genes for IGF-I and IGF-II to human chromosomes 12 and 11, respectively. We present evidence that the IGF-II gene is located on the short arm of chromosome 11 with a ras proto-oncogene and the insulin structural gene, and also suggest the existence of a fragment length polymorphism using the IGF-I probe.     

Tissue-specific activation of a cloned alpha-fetoprotein gene during differentiation of a transfected embryonal carcinoma cell line

To identify cis-acting DNA elements involved in the activation of the alpha-fetoprotein gene during differentiation, modified copies of the gene were introduced into murine F9 embryonal carcinoma cells. The differentiation of the transformants to either parietal or visceral endoderm was accompanied by induction of the exogenous template in a manner qualitatively, but not quantitatively, identical to that of the endogenous alpha-fetoprotein gene.     

A novel fluorination reaction: The interaction of perchloryl fluoride with active methylene compounds

Zusammenfassung Die Reaktion von Perchloryl Fluorid (PF) mit Anionen wurde untersucht. Eine leichte Difluorierung fand statt mit Carbanionen vom Typus CH (C=X)₂. Mechanismen für die verschiedenen Heterolysen von PF werden vorgeschlagen.     

Locomotory energetics in a marsupial (Antechinomys spenceri) and a rodent (Notomys alexis).

Steady state oxygen consumption was compared in a rodent Notomys alexis and a marsupial Antechinomys spenceri. The marsupial was found to diverge from predicted eutherian energic patterns. N. alexis appears to use energy storage as a significant part of the step cycle before becoming bipedal. Aerobic scope and heat storage during running are similar in both species.