A simple electronic apparatus for the analysis of radioactively labeled gel electrophoretograms

Radioactively labeled gel electrophoretograms are generally analyzed either by slicing the gel and dissolving the individual pieces in a fluor for scintillation counting or by exposure to photographic emulsions. In this report, we describe a technique for fast quantitative analysis of such electrophoretograms, based on counting individually β-or γ-particles emerging from the gel surface and locating their position to ±0.6 mm. The apparatus which employs a position-sensitive single-wire gas proportional counter is simple to construct and operate with readily available electronics.     

Whole protein uptake and metabolism by mouse blastocysts

Preimplantation mouse embryos take up whole 125I-labelled BSA from their environment. In blastocysts this uptake was temperature-sensitive and reversibly inhibited by trypan blue: properties consistent with an endocytotic mechanism. The uptake kinetics indicate that a saturable component predominates at low protein concentrations, but a non-saturable component is the major uptake route at higher concentrations. This suggests that BSA is pinocytosed probably bound to the membrane and dissolved in the bulk solvent phase. The rate of uptake, equivalent to about 5 pl/min/blastocyst was similar to that reported for non-saturable glycine uptake. In blastocysts the protein is degraded to acid-soluble products. At reported genital tract fluid protein concentrations this would represent a significant contribution to the embryonic pool of fixed nitrogen.     

Regional assignment of the mouse alpha A2-crystallin gene (Crya-1) to chromosome 17A3----B by in situ hybridization

Previously, we assigned the alpha A2-crystallin (Crya-1) structural gene to mouse chromosome 17 via Southern blot hybridization analysis of mouse x Chinese hamster somatic cell hybrids. Using in situ hybridization, we have now localized this gene to 17A3----B, a subchromosomal region containing several genes whose linkage relationships have been shown to be conserved on human chromosome 6. In man, however, the homologous gene (CRYA1) is located on human chromosome 21, indicating that internal rearrangements can occur within highly conserved chromosomal regions during the divergence of man and mouse.