The murine retinoblastoma homolog maps to chromosome 14 near Es-10

Restriction fragment length variants have been exploited to map genetically Rb-1, the murine homolog of the human retinoblastoma gene. Rb-1 localized to mouse chromosome 14 on the basis of results from analysis of somatic cell hybrids. In an interspecific backcross involving Mus spretus, Rb-1 and the murine homolog of the human esterase D gene (ESD), which we refer to here as Esd, were inseparable. Furthermore, the strain distribution patterns of Rb-1 and Es-10 are the same in 31 of 32 recombinant inbred strains. Close linkage of the chromosome 14 morphological marker hairless (hr) to Rb-1 is also implied. These results localize Rb-1 on the mouse linkage map and provide close genetic markers to follow Rb-1 in somatic as well as in germline genetic experiments. Additionally, the results suggest that Es-10 is the murine homolog of ESD and provide further evidence for linkage conservation during mammalian evolution.     

Arylsulphatase A and acid phosphatase activities in plasma and leucocytes during LPS fever in the ox (Bos taurus)

Intravenous injection of E. coli LPS (0.5 micrograms/kg) produced the biphasic elevation of rectal temperature (TR) in conscious oxen. The fever was accompanied by a significant increase of the arylsulphatase A (AsA) activities in plasma and in mononuclear leucocytes. In polymorphonuclear cells a substantial decrease of the AsA activity after 1 hr fever was observed. After 3.5 hr of fever the polymorphonuclear activity of AsA restored to normal found before LPS administration. In contrast with AsA, the pyrogenic dose of LPS caused negligible changes of the acid phosphatase (AcP) activities in the sampled materials. Daily-repeated injections of pyrogen into the same oxen attenuated magnitudes of fever as well as AsA responses in plasma and granulocytes. Heat-induced hyperthermia provoked only minute changes of the AsA and AcP.     

Genetics mapping of the gene coding for the integrin β7 subunit to the distal part of mouse chromosome 15

Address correspondence and offprint requests to: G. W. Krissansen.     

The Genes Encoding the Somatic and Testis-Specific Isotypes of the Mouse Cytochrome c Genes Map to Paralogous Regions of Chromosomes 6 and 2

Using mouse probes specific to cytochrome c_S and to cytochrome c_T, the single-copy genes encoding these two proteins have been mapped to paralogous chromosomal regions by analysis of restriction fragment length variants in interspecific crosses. The gene for cytochrome c_S, Cycs, maps to a position between Tcrb and Cbl-1 on proximal mouse Chromosome 6, and the gene for cytochrome c_T, Cyct, maps between Gad-1 and Sfpi-1 on mouse Chromosome 2.