Allelic variants of Ly-5 in inbred and natural populations of mice

Allelic variants of Ly-5 in inbred commensal and other natural populations of mice were analyzed by patterns of restriction fragment length polymorphisms (RFLP) and Southern hybridization using an Ly-5 cDNA probe and by cell-surface staining with a panel of antibodies directed against polymorphic and nonpolymorphic Ly-5 determinants. New Ly-5 alleles were defined by RFLPs generated by both Eco RI and Bam HI restriction enzyme digests. The Mus musculus subspecies and other species within the genus Mus showed a strong correlation between allelic variants defined by restriction enzymes and serologic specificities. The data also suggest the conservation of the Ly-5 gene throughout the genus Mus.     

Mapping of the bcl-2 oncogene on mouse chromosome 1

Two bcl-2 alleles have been identified in inbred strains of mice by restriction fragment length polymorphism (RFLP). Analysis of a bcl-2 RFLP in a series of bilineal congenic strains (C.D2), developed as a tool for chromosomal mapping studies, revealed linkage of bcl-2 to the Idh-1/Pep-3 region of murine chromosome 1. The co-segregation of bcl-2 alleles with allelic forms of two other chromosome 1 loci, Ren-1,2 and Spna-1, in a set of back-cross progeny, positions bcl-2 7.8 cM centromeric from Ren-1,2.     

The mouse alpha 1(XII) and human alpha 1(XII)-like collagen genes are localized on mouse chromosome 9 and human chromosome 6.

Type XII collagen is a member of the FACIT (fibril-associated collagens with interrupted triple helices) group of extracellular matrix proteins. Like the other members of this group, collagen types IX and XIV, type XII has alternating triple-helical and non-triple-helical domains. Because of its structure, its association with collagen fibrils, and its distribution in dense connective tissues, type XII is thought possibly to act as a cross-bridge between fibrils and resist shear forces caused by tension. A portion of the ffuse gene was isolated by screening a genomic library with a chicken alpha 1 (XII) cDNA probe, followed by subcloning and sequence analysis. Comparison of exon sequences with the sequence of a mouse cDNA clone allowed the mouse gene to be identified as the alpha 1 (XII) collagen gene. In the mouse, Col12a1 is located on chromosome 9, as determined by linkage analysis using DNA from interspecific backcrosses with Mus spretus. Screening of a human genomic library also allowed the isolation of a human alpha 1(XII)-like gene (CoL12A1). This gene was mapped to chromosome 6 by blot hybridization to DNA from human/hamster hybrid cell lines. This information should prove useful in determining the role of type XII collagen genes as candidate genes in inheritable connective tissue diseases.     

Localization of growth arrest-specific genes on mouse Chromosomes 1, 7, 8, 11, 13, and 16

Growth arrest in NIH3T3 cells is associated with increased expression of a variety of mRNAs, several of which have been isolated as cDNA clones. Six of these growth arrest-specific (Gas) genes were mapped by following the inheritance of DNA restriction fragment length variants (RFLVs) associated with them in panels of recombinant inbred (RI) strains of mice and in the progeny of backcrosses both between laboratory mouse strains and between a laboratory strain and Mus spretus. The six genes are unlinked. Gas-1 maps to Chromosome (Chr) 13, Gas-2 to Chr 7, Gas-3 to Chr 11, Gas-4 to Chr 16, Gas-6 to Chr 8, and Gas-10 to Chr 1.     

Purification and characterization of protease-resistant secretory granule proteoglycans containing chondroitin sulfate di-B and heparin-like glycosaminoglycans from rat basophilic leukemia cells

Proteoglycans were extracted from nuclease-digested sonicates of 10(9) rat basophilic leukemia (RBL-1) cells by the addition of 0.1% Zwittergent 3-12 and 4 M guanidine hydrochloride and were purified by sequential CsCl density gradient ultracentrifugation, DE52 ion exchange chromatography, and Sepharose CL-6B gel filtration chromatography under dissociative conditions. Between 0.3 and 0.8 mg of purified proteoglycan was obtained from approximately 1 g initial dry weight of cells with a purification of 200-800-fold. The purified proteoglycans had a hydrodynamic size range of Mr 100,000-150,000 and were resistant to degradation by a molar excess of trypsin, alpha-chymotrypsin, Pronase, papain, chymopapain, collagenase, and elastase. Amino acid analysis of the peptide core revealed a preponderance of Gly (35.4%), Ser (22.5%), and Ala (9.5%). Approximately 70% of the glycosaminoglycan side chains of RBL-1 proteoglycans were digested by chondroitinase ABC and 27% were hydrolyzed by treatment with nitrous acid. Sephadex G-200 chromatography of glycosaminoglycans liberated from the intact molecule by beta-elimination demonstrated that both the nitrous acid-resistant (chondroitin sulfate) and the chondroitinase ABC-resistant (heparin/heparan sulfate) glycosaminoglycans were of approximately Mr 12,000. Analysis of the chondroitin sulfate disaccharides in different preparations by amino-cyano high performance liquid chromatography revealed that 9-29% were the unusual disulfated disaccharide chondroitin sulfate di-B (IdUA-2-SO4----GalNAc-4-SO4); the remainder were the monosulfated disaccharide GlcUA----GalNAc-4-SO4. Subpopulations of proteoglycans in one preparation were separated by anion exchange high performance liquid chromatography and were found to contain chondroitin sulfate glycosaminoglycans whose disulfated disaccharides ranged from 9-49%. However, no segregation of subpopulations without both chondroitin sulfate di-B and heparin/heparan sulfate glycosaminoglycans was achieved, suggesting that RBL-1 proteoglycans might be hybrids containing both classes of glycosaminoglycans. Sepharose CL-6B chromatography of RBL-1 proteoglycans digested with chondroitinase ABC revealed that less than 7% of the molecules in the digest chromatographed with the hydrodynamic size of undigested proteoglycans, suggesting that at most 7% of the proteoglycans lack chondroitin sulfate glycosaminoglycans.(ABSTRACT TRUNCATED AT 400 WORDS)     

Production of a potentially novel anti-microbial substance by Bacillus polymyxa

A bacterial strain, SCE2, identified as Bacillus polymyxa, produced an anti-microbial substance active against yeasts, fungi and different genera of Gram-positive and-negative bacteria, in liquid medium and in plate assays. This substance appeared to be an antibiotic different from the polymyxin group, mainly because of its action against the majority of Gram-positive bacteria tested and its lack of activity against Pseudomonas aeruginosa, a species usually killed by polymyxins. Preliminary characterization showed resistance to heat (65°C, 2 h), to proteases, trypsin, lysozyme, deoxyribonuclease I, ribonuclease A, phospholipase C, ethanol, acetone, chloroform, ether and to strong alkali treatment (2 M NaOH). The molecular weight was less than 3500. The B. polymyxa strain harboured a plasmid that did not correlate with antibiotic production; after curing experiments, a derivative strain, SCE2(46), was isolated that lacked the plasmid pES1, but showed the same inhibitory spectrum as the wild-type strain.     

Mouse chromosome 1

Chair of Committee for Mouse Chromosome 1