Absence of Transient Elevated UV Resistance during Germination of Bacillus subtilis Spores Lacking Small, Acid-Soluble Spore Proteins α and β

Germinating spores of Bacillus subtilis mutants which lack small, acid-soluble spore proteins α and β did not exhibit the transient elevated UV resistance seen during germination of wild-type spores.     

Scoring mitotic activity in longitudinal sections of crypts of the small intestine

Various counts have been made of the number of mitotic figures in whole crypts and sections of crypts of the small intestine of the mouse. Samples were analysed from animals killed at different times of the day and at different times after administration of vincristine. Measurements have been made of the size of mitotic and interphase nuclei and of the radial position of mitotic figures. The correction factor, f, which is required to take into account the enhancement of mitotic counts in sections as a consequence of their centripetal position has been investigated. The results indicate the following: (1) transverse sections of the crypt differ from longitudinal sections if they involve cutting the intestine before fixation which may result in a relaxation of the crypt and its widening by 25%; (2) columnar cell nuclei have a shape that resembles a sphere flattened so that the average diameter is 20% greater in crypt transverse sections; (3) mitotic nuclei tend to be about half-way between the crypt edge and the central axis of the crypt; (4) between about four and seven times more mitotic figures have their mitotic axis parallel to the long axis of the crypt; (5) about one-third of all mitotic figures in a crypt are seen in a longitudinal section of the crypt. If this is related to the number of cells in the crypt as a whole and in a section, a correction factor fD for the mitotic index of 0.59 is obtained; (6) the correction factor fT derived from the shape and position of the mitotic figures measured in 3 microns longitudinal sections is 0.53; (7) relating cell cycle and mitotic accumulation data using a computer-based model of the crypt also permits a correction factor fmod to be estimated. This gives a value of 0.66. When sectioned material is used to calculate a mitotic index the most appropriate correction factor is fD; for mouse small intestine it is 0.59.     

Seasonally of adult male japanese macaques (Macaca fuscata): Androgens and behavior in a confined troop

Seasonal variations in levels of serum testosterone, dihydrotestosterone (DHT), reproductive behavior, and social behavior were investigated in 12 adult males (5 to 20 + years of age) of the Oregon troop of Japanese macaques (Macaca fuscata). Blood samples were collected at 2- to 4-month intervals, and behaviors were monitored twice weekly over a 15-month period. Significant seasonal variations in levels of testosterone and DHT, and in frequencies of mount series, ejaculations, number of female partners, displays, courtship, and aggression were observed. Seasonal variations in reproductive and social behaviors did not correlate with seasonal variations in androgen levels because seasonal increases in these behaviors followed seasonal increases in the androgens with a 1- to 2-month delay. However, significant correlations between increased androgen levels and the onset of mating activity occur when mean monthly frequencies of mount series are shifted 1 to 2 months earlier to coincide with the rise in serum androgen levels. The frequency of adult male play and male-male mounting increased significantly when androgen levels were low. We suggest that photoperiod changes may function as a proximate cue in male Japanese macaques which induces a state of biological readiness for mating, and the behavioral consequences (i.e., mating) are then dependent upon the presence of receptive females.     

Binding of Germanium to Pseudomonas putida Cells

The binding of germanium to Pseudomonas putida ATCC 33015 was investigated by using whole intact cells grown in a medium supplemented with GeO₂ and catechol or acetate. Electron-microscopic examination of the control and metal-loaded samples revealed that germanium was bound within the cell envelope. A certain number of small electron-dense deposits of the bound element were found in the cytoplasm when the cells were grown in the presence of GeO₂ and catechol. The study of germanium distribution in cellular fractions revealed that catechol facilitated the intracellular accumulation of this element.     

DNA sequence evidence for polymorphic forms of human serum amyloid A (SAA)

Serum amyloid A (SAA) is an acute-phase reactant and precursor to amyloid A protein, the major constituent of the fibril deposits of reactive amyloidosis. The factors determining whether the 104-amino acid SAA molecule is converted into the 76-amino acid amyloid A protein and deposited as fibrils are not known. As an initial step toward investigating the possibility that a particular primary structure of SAA is involved in amyloid formation, we have cloned and determined the nucleotide sequence of human SAA-specific cDNAs. The first clone, selected using an oligonucleotide probe, was shown to encode the signal peptide and amino-terminal region of SAA. The cDNA of this clone served as probe in the selection of two distinct, full-length SAA cDNAs, initially differentiated by the presence (pSAA21) or absence (pSAA82) of a PstI site in the coding sequence. The complete nucleotide sequence of pSAA82 cDNA was determined. Since there appear to be multiple human SAA alleles, it is conceivable that their differential expression is important to amyloid formation.     

Complementation analysis of the inorganic carbon concentrating mechanism of Chlamydomonas reinhardtii

Summary Six independently isolated mutants of Chlamydomonas reinhardtii that require elevated CO₂ for photoautotrophic growth were tested by complementation analysis. These mutants are likely to be defective in some aspect of the algal concentrating mechanism for inorganic carbon as they exhibit CO₂ fixation and inorganic carbon accumulation properties different from the wild-type. Four of the six mutants defined a single complementation group and appear to be defective in an intracellular carbonic anhydrase. The other two mutations represent two additional complementation groups.Abbreviations HS high salt medium which has 13 mM phosphate at pH 6.8 - HSA high salt plus 36 mM acetate medium - YA high salt medium with 4 g yeast extract per L and 36mM acetate - Arg arginine - cia^- CO₂ accumulation mutants that cannot grow on low CO₂ - C_i inorganic carbon (CO₂+HCO _- ³ ) - CA carbonic anhydrase - mt mating type Supported in part by the McKnight Foundation and by NSF grant PCM 8005917 and published as journal article 11924 from the Michigan State Agriculatural Experiment Station     

Enhancement of Oxygen-Evolution in Photosystem II-Phycobilisome Particles from Porphyridium cruentum

Oxygen-evolving photosystem II-phycobilisome particles froma red alga were inhibited 50–80% by aging, dilution, lowpH and salt-washing. Bovine serum albumin, and dithiothreitolwere found to stimulate activity in all but salt-washed particles.CaCl₂ and MnCl₂ partially restored activity lost after agingor dilution. ¹Current address: Waksman Institute of Microbiology, RutgersUniversity, Piscataway, New Jersey 08854-0759, U.S.A. (Received October 5, 1985; Accepted March 31, 1986)     

Three related centromere proteins are absent from the inactive centromere of a stable isodicentric chromosome

We developed an aqueous spreading procedure that permits simultaneous analysis of human chromosomes by Q-banding and indirect immunofluorescence. Using this methodology and anticentromere antibodies from an autoimmune patient we compared the active and inactive centromeres of an isodicentric X chromosome. We show that a family of structurally related human centromere proteins (CENP-A, CENP-B, and CENP-C) is detectable only at the active centromere. These antigens therefore may be regarded both as morphological and functional markers for active centromeres.