Antipeptide antibodies to the 141-1141-1141-1receptor confirm the extracellular orientation of the amino-terminus and the putative first extracellular loop

Summary We developed site-directed rabbit antisera against synthetic peptides selected from the deduced amino acid sequence of the hamster lung ₂-adrenergic receptor (amino acids 16–31 and 174–189, respectively). All antisera directed against peptide 1 (four of four rabbits) as well as two antisera directed against peptide 2 (two of four rabbits) recognized the purified ₂-adrenergic receptor in immunoblot conditions when used at a dilution of 1500. Antisera directed against peptide 1 as well as peptide 2 were able to immunoprecipitate iodinated as well as¹²⁵I-cyanopindolol tabeled ₂-adrenergic receptor. This last result implies that the recognized epitopes do not contain the¹²⁵I-cyanopindolol binding domain of the ₂-adrenergic receptor. Immunoblot experiments performed on membrane fractions from hamster lung tissue showed that immunoreactive bands at 64,000, 57,000, 47,000, 44,000 and 38,000 daltons were specifically detected. When purified ₂-adrenergic receptor was iodinated and submitted to glycolytic and/or tryptic treatments, species with similar molecular weights could be recovered. Then, the immunoreactive bands probably correspond to native ₂-adrenergic receptor and to degradative or nonglycosylated species of this molecule. The antisera were also able to detect immunoreactive molecules in murine and human cell lines, suggesting conservation of the probed sequences between these species. Enzymatic linked immunosorbent assay tests on intact cells and immunofluorescence studies confirmed that the amino-terminus and putative first extracellular loop are extracellularly located. Immunofluorescence studies on mouse brain primary cultures showed that cells expressing ₂-adrenergic receptor-like molecules exhibited a neuronal phenotype.     

Isolation of polysaccharide-free DNA from plants

A quick procedure for the isolation of polysaccharide-free DNA from different plant species and cell suspension or callus cultures is described. The originality of the method lies in the use of a mixture of glycoside hydrolases that leads, after phenol and chloroform extraction, to the isolation of pure DNA without any polysaccharide contamination. The highly purified DNA can be used for nucleotide analysis by HPLC, RFLP analysis and PCR amplification.     

The gene coding for the α1 subunit of the skeletal dihydropyridine receptor (Cchl1a3=mdg) maps to mouse Chromosome 1 and human 1q32

Using both chromosomal in situ hybridization and molecular techniques, we report the genetic localization of the gene coding for the alpha 1 subunit of the skeletal slow Ca²⁺ current channel/DHP receptor gene (Cchl1a3) on human Chromosome (Chr) 1 (1q31–1q32 region) and on mouse Chr 1 region (F-G). On the basis of single-strand conformation polymorphism (SSCP-PCR) analysis in an interspecific backcross, we have determined that the Cchl1a3=mdg (muscular dysgenesis) locus is very closely linked to the myogenin (Myog) locus.     

16S-23S and 23S-5S intergenic spacer regions of Streptococcus thermophilus and Streptococcus salivarius,primary and secondary structure

The 16S-23S intergenic spacer region (spacer region 1) of Streptococcus salivarius, S. thermophilus, and Lactococcus lactis subsp. cremoris and the 23S-5S intergenic spacer region (spacer region 2) of S. salivarius and L. lactis subsp. cremoriswere sequenced and compared with the spacer regions 1 and 2 of other streptococci. A high degree of intraspecific conservation was observed for S. thermophilus and L. lactis, and very similar sequences were found for S. salivarius and S. thermophilus. Whereas spacer region 1 is highly conserved in the genus Streptococcus sensu-stricto,only the tRNA gene and the rRNA processing stems are highly conserved in the three genera: Streptococcussensu-stricto, Lactococcus, and Enterococcus. The presence of a unique tRNA^Ala gene without the 3 terminal CCA sequence seems to be a general feature of the streptococci spacer region 1. A secondary structure model was built to show the interaction between the spacer regions 1 and 2 of S. thermophilus and S. salivarius. The rapid evolution of spacer region 1 in streptococci is in part due to insertions and deletions of small RNA stem/loop structures.     

Physical map of DNA from a new cauliflower mosaic virus strain

The restriction enzymes AluI, BamHI, BglII, EcoRI, HindIII, and SalI have been used to characterize and map a new cauliflower mosaic virus strain (Cabb-S). These fragments have been ordered by examining their overlapping regions after double enzymatic digestion. The single SalI cleavage site was chosen as the point of origin. We compare this strain with those already described.     

Révision du genreProstrepsiceros Major 1891 (Mammalia,Bovidae)

The study of new fossils from the Miocene of Macedonia (Greece) has led us to a revision of the genusProstrepsiceros, which we propose to divide into two subgenera:P. (Prostrepsiceros) andP. (Helicotragus), these subgenera comprising respectively two and three species.     

Recherche D'enzymes intracellulaires dans le genre schizosaccharomyces. Implications systématiques

In the genus Schizosaccharomyces intracellular osidases and nitrite and nitrate reductases are revealed; particularly all the species possessing invertase, -glucosidase and -galactosidase. These characters underline the homogeneity of the genus. On the basis of osidases, nitrite and nitrate reductases results, 2 groups can be distinguished in this genus.