Ovarian function and pregnancy rates in reindeer calves (Rangifer tarandus ) in Southern Norway

Reindeer calves (n = 632) were slaughtered in November/December (n = 476) or in January (n = 156). Dressed weights and amount of perirenal fat were recorded, and the reproductive organs were collected. A separate group of 130 reindeer calves were weighed at 7 months of age and were followed up with repeated weighings and pregnancy examinations up to 21 months. The onset of puberty and the pregnancy rate were significantly influenced by body weight and the amount of perirenal fat. Approximately 60 g of perirenal fat and 22 kg dressed weight were found at the lower limits for pregnancy. A total of 222 (35%) animals had reached puberty and 126 (20%) were pregnant when examined after slaughter. Animals which conceived during their first autumn showed only a moderate weight gain the following year, and the calf mortality rate in these animals was 47.4%. It was concluded that calf pregnancies are common among the reindeer of Southern Norway and that measures need to be taken to prevent them.     

Plant protoplasts and genetic engineering II

Book Review

Plant protoplasts and genetic engineering IIY.P.S. Bajaj (Ed.), (Biotechnology in Agriculture and Forestry, Vol. 9). Berlin: Springer-Verlag, 1989. 510 pages. DM398.00. ISBN 3-540-50789-2     

Transcriptional regulation by the nuclear receptor superfamily

In the past year, additional experimental data have expanded our understanding of the molecular mechanisms that underlie nuclear receptor control of regulatory programs. It is increasingly clear -that steroid members (e.g. glucocorticoid and estrogen) and non-steroid members (e.g. retinoic acid, thyroid hormone, and vitamin D) of the nuclear receptor superfamily may utilize distinct strategies in achieving their complex control of gene regulation.     

Complete enzymatic deglycosylation of native sex steroid-binding protein (SBP or SHBG) of human and rabbit plasma: effect on the steroid-binding activity.

An enzymatic procedure for the complete removal of the N-linked and O-linked oligosaccharide side chains of the sex steroid-binding proteins (SBP or SHBG) of human and rabbit plasma under native conditions is described. Deglycosylation was catalyzed by N-glycanase, neuraminidase, and O-glycanase and was monitored by SDS-PAGE, lectin blotting, and molecular weight analyses by electrospray mass spectrometry. Digestion of rabbit SBP with N-glycanase generated a major 39,777-Da protein and two minor ones of 39,389 and 39,545 Da. The molecular weight of the major protein agrees with the molecular weight calculated from the sequence of the sugar-free polypeptide monomer (39,769 Da: Griffin, P.R., Kumar, S., Shabanowitz, J., Charbonneau, H., Namkung, P.C., Walsh, K.A., Hunt, D.F., & Petra, P.H., 1989, J. Biol. Chem. 264, 19066-19075), whereas the other two are deglycosylated proteolytic cleavage products lacking the TQR and TQ sequences at the amino-terminus. The N- and O-linked side chains of human SBP were removed by sequential digestion with N-glycanase and neuraminidase/O-glycanase. A 38,771-Da protein was generated, which agrees well with the molecular weight of the sugar-free polypeptide monomer (Walsh, K.A., Titani, K., Kumar, S., Hayes, R., & Petra, P.H., 1986, Biochemistry 25, 7584-7590). N-deglycosylation of human and rabbit SBP has no effect on the steroid-binding activity, but removal of the O-linked side chains of N-deglycosylated human SBP results in an apparent 50% loss of steroid-binding activity and an increase in the Kd for the binding of 5 alpha-dihydrotestosterone from 0.3 mM to 0.9 nM.(ABSTRACT TRUNCATED AT 250 WORDS)     

Enzyme patterns during substrate shifts between phenol,acetate and glucose in continuous culture of Trichosporon cutaneum

Summary The soil yeast Trichosporon cutaneum was grown in continuous culture on phenol, acetate or glucose as sole carbon source. The activities of enzymes participating in the tricarboxylic acid cycle, glyoxylate cycle, 3-oxoadipate pathway, pentose phosphate pathway and glycolysis were determined in situ during shifts of carbon sources. Cells grown on phenol or glucose contained basal activity of the glyoxylate-cycle-specific isocitrate lyase. The derepression of the glyoxylate cycle enzymes was partly hindered in the presence of phenol but not in the presence of low levels of glucose. Phenol and glucose caused repression of isocitrate lyase. In the presence of either phenol or glucose, acetate accumulation in the medium increased. However, part of the supplied acetate was utilized simultaneously with phenol or glucose, the utilization rate of either carbon source being reduced in the presence of the other carbon source. Acetate caused repression but not inactivation of the phenol-degrading enzymes, phenol hydroxylase and catechol 1,2-dioxygenase. The simultaneous utilization of phenol and other carbon sources in continuous culture as well as the observed repression-derepression patterns of the involved enzymes reveal T. cutaneum to be an organism of interest for possible use in decontamination processes. Offprint requests to: H. Y. Neujahr Offprint requests to: H. Y. Neujahr     

Different oligosaccharides accumulate in the brain and urine of a cat with α-mannosidosis: structure determination of five brain-derived and seventeen urinary oligosaccharides

Five brain-derived and 17 urinary oligomannose-type oligosaccharides were isolated by ion-exchange chromatography on Mono Q or Dowex, followed by HPLC on Lichrosorb-NH₂ from a Persian cat suffering from -mannosidosis. The structures ofthe carbohydrate chains were determined by 500- or 600-MHz¹H-NMR spectroscopy. Different oligosaccharide patterns were found in brain and urine. 99% of the urinary oligosaccharides possess an (1-6)-linked mannose residue attached to -mannose, whereas only 5% of the brain-derived oligosaccharides contain such a residue. Furthermore, of the urinary carbohydrate chains 71% end with Man1-4GlcNAc1-4GlcNAc and 29% end with Man1-4GlcNAc, whereas the corresponding amounts are 23% and 77%, respectively, for the brain-derived oligosaccharides.Abbreviations MLEV-17 composite pulse devised by M. Levitt - HOHAHA homonuclear Hartman-Hahn spectroscopy - TPPI time-proportional phase incrementation - 2D two dimensional - GlcNAc N-acetylglucosamine - Man mannose - Fuc fucose     

Biphasic changes in leukocytes induced by strenuous exercise

Seven healthy male volunteers participated in short- (STR, 1.7 km), middle- (MTR, 4.8 km) and long- (LTR, 10.5 km) term runs at a speed close to their maximum. A prompt mobilization of white cells, and lymphocytes in particular, appeared following the exercise. The initial increase in the number of lymphocytes was succeeded by a significant decrease [(P less than 0.03) lymphopenial], which on average was 32%-39% of the pre-exercise values in all groups. A close correlation was found between the initial increase in plasma cortisol concentration after exercise and the subsequent lymphopenia. A modest enhancement in the number of granulocytes immediately after the exercise was accompanied by a comprehensive increase in polymorphonuclear (PMN) elastase concentration accounting for 78.6%, SEM 16.3%, 140.7%, SEM 31.8% and 241.3%, SEM 48.1% in the STR, MTR and LTR groups. No correlation was found between granulocyte number and the plasma PMN elastase concentration. A delayed granulocytosis was noted in all subjects, reaching a peak between 2 and 4 h after the exercise. The magnitude of the granulocytosis varied among subjects and peak values of the number of circulating granulocytes were found to be 5.7 x 10(9) cells.l-1, SEM 0.5, 6.7 x 10(9) cells.l-1, SEM 0.6 and 8.8 x 10(9) cells.l-1, SEM 0.5 in STR, MTR and LTR respectively, whereas the mean baseline value was 3.6 x 10(9) cells.l-1, SEM 0.4. The neutrophilic granulocytosis was not accompanied by a corresponding enhancement in PMN elastase concentration. The plasma cortisol concentration reached a peak 30 min after exercise and declined below the control level in 4 h. Neither the initial increase, nor the subsequent decrease in plasma cortisol concentration were found to be essential for the magnitude of the delayed leukocytosis.     

Construction of interleukin-1 alpha mutants using unequal contamination of synthetic oligonucleotides.

Proteins without readily available three-dimensional structural data present a difficult problem in the exploration of structure/function relationships. Saturation mutagenesis using contaminated oligonucleotides can identify potentially interesting regions of such a protein. This technique, in which synthesized oligonucleotides contain low-level base substitutions, allows random mutations to be placed throughout a gene sequence. Using double-stranded cassettes, a region of the human interleukin-1 alpha gene has been altered using such mutagenic oligonucleotides. However, instead of contaminating both strands of the gene sequence at the same level, each strand of the insert was contaminated at a different level. Several recombinants were sequenced and the effects of the mutations on the activity of the proteins were examined. Contaminating the two oligonucleotides at different levels produced a significantly different distribution of nucleotide changes from that seen if both strands were contaminated at the same level. The observed distribution followed the average of the distributions for each of the two contamination levels. This resulted in roughly equal frequencies of 1 to 5 nucleotide changes per clone with very few clones containing the wild-type nucleotide sequence. This helped overcome the redundancy in the genetic code, resulting in a high frequency of amino acid changes, and allowed changes at every amino acid to be sampled in a small number of mutants. This procedure can allow a gene sequence to be screened rapidly by removing most wild-type sequences from analysis while making sure that there are many amino acid changes in the resultant mutants.     

Chemical coding of endocrine cells of the airways: presence of helodermin-like peptides

Summary The epithelium of the airways is rich in endocrine cells containing serotonin and/or a wide variety of regulatory peptides. These cells usually occur in clusters in the lungs but are also found scattered in the larynx and trachea. In the present study, endocrine cells in the airways of mouse, rat, hamster, guinea pig, pig, sheep and squirrel monkey were examined for the presence of serotonin, helodermin-like peptides and other regulatory peptides using immunocytochemistry and radioimmunoassay. In addition, we looked for the protein gene product 9.5 (PGP), which occurs in many peptide hormone-producing endocrine cells in the body. Both clustered and scattered endocrine cells in the airways were found to display coexistence of serotonin and peptides, such as a helodermin-like peptide, calcitonin and calcitonin gene-related peptide (CGRP). The PGP-immunoreactive cells were numerous and included elements containing serotonin and/or regulatory peptides. An additional PGP-immunoreactive endocrine cell population lacked serotonin and regulatory peptides. Helodermin-immunoreactive material was demonstrated in endocrine cells of the airways in the mouse and hamster but not in any of the other species studied. Serotonin was an endocrine cell constituent in all the species studied. Calcitonin and CGRP could be demonstrated by immunocytochemistry in the mouse, rat, and hamster, but not in the guinea pig, sheep, pig and monkey. In the hamster airways double immunostaining indicated that the helodermin-like peptide occurred in a subpopulation of the CGRP- and serotonin-containing cells. Most of the CGRP-containing cells stored serotonin; some of them also contained calcitonin. The chemical coding of these cells resembled that of the thyroid C cells.