Echolocation sounds and hearing of the greater Japanese horseshoe bat (Rhinolophus ferrumequinum nippon)

Summary The relationship between the orientation sounds and hearing sensitivity in the greater Japanese horseshoe bat,Rhinolophus ferrumequinum nippon was studied.An orientation pulse consisted of a constant frequency (CF) component followed by a short downward frequency-modulated (FM) component. Sometimes, an initial upward FM component preceded the CF component. Duration of pulses was about 30 ms and the CF of resting pulses (RF) averaged 65.5 kHz. The best frequency (BF) at the lowest threshold in audiograms as measured by the pinna reflex averaged 66.1 kHz. Audiograms showed remarkable sharp cut-offs on both sides near the BF. The frequency difference between the BF and the RF was about 0.6 kHz, and the RF was always below the BF. The values of RF and BF were characteristically different from those of the European subspecies,Rhinolophus ferrumequinum ferrumequinum.Abbreviations BF best frequency - CF constant frequency - FM frequency modulated - RF resting frequency     

Quantitative structure-activity relationships of structurally similar odorless and odoriferous benzenoid musks

To reveal the difference of molecular property between structurallysimilar odorless and odoriferous musk compounds, 10 pairs ofbenzenoids (monocyclic-, dicyclic- and tricyclic-) were examined.Molecular structures of all compounds were optimized by MNDO(modified neglect of diatomic differential overlap) consideringconformation. Parameters effective in discriminating two groups,group A of 10 odorless compounds and group B of 10 musk odorcompounds, were searched from 34 candidate parameters by adaptiveleast squares. The best three parameters found were log P value(octanol/water partition coefficient), the longest side lengthof hexahedron circumscribing a molecule, and the parameter whichexpresses structural hindrance to the functional group whena molecule approaches the receptor site. The two groups of compoundswere completely discriminated using these three parameters.     

Changes in Volatile C6-Aldehydes Emitted from and Accumulated in Tea Leaves

C₆-Aldehydes emitted from intact tea leaves were analyzed quantitatively.Emission of the aldehydes increased temporarily in mid-May whenenzymatic activities involved in aldehyde formation from lipidsbegan to increase. Levels of C₆-aldehydes in tea leaves alsoincreased temporarily. However, the accumulated C₆-aldehydesdid not always correspond to emitted ones. (Received December 1, 1991; Accepted March 18, 1992)     

Effect of the recombinant vaccinia viruses that express HTLV-I envelope gene on HTLV-I infection.

The human T-lymphotropic virus type I (HTLV-I) is etiologically linked to adult T-cell leukemia (ATL). To develop a vaccine against ATL, we constructed recombinant vaccinia viruses containing the envelope gene of HTLV-I in the vaccinia virus hemagglutinin (HA) gene, a new site where foreign genes can be inserted. A single inoculation of the recombinant virus induced antibodies to the env proteins of HTLV-I in rabbits and had a protective effect against HTLV-I infection.     

Reciprocal effects of epidermal growth factor and transforming growth factor beta on the anchorage-dependent and -independent growth of A431 epidermoid carcinoma cells

The effects of epidermal growth factor (EGF) and transforming growth factor beta (TGF beta) on the growth of A431 epidermoid carcinoma cells were studied. Whereas the monolayer growth of A431 cells was inhibited by EGF, it was stimulated by TGF beta. Contrary to the effects on the monolayer growth, EGF stimulated the soft agar growth of A431 cells. The stimulatory effects of TGF beta on the anchorage-dependent growth were antagonized by EGF and those of EGF on anchorage-independent growth were antagonized by TGF beta. These results suggest that both factors not only convey the proliferative signals to A431 cells but also induce phenotypic changes, resulting in a preference for either anchorage-dependent or anchorage-independent growth. Moreover, as the stimulatory effects of EGF on the soft agar growth of A431 cells paralleled its reported stimulatory effects on their in vivo growth, it is also suggested that in vivo responses of cells to certain growth factors may correlate better with their responses in soft agar culture than with those in monolayer culture.     

Synthesis of Proteins Enriched in Li+- Induced Vegetalized Embryos of Sea Urchin during Early Development

Sea urchin embryos were vegetalized by a pulse treatment with 60 mM Li⁺ between 2.5 hr and 6 hr after fertilization at 20°C. Normal and Li⁺ -treated embryos were exposed to [³⁵S]-methionine for 2 hr at various stages and [³⁵S]-labeled proteins were analyzed by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE). On fluorograph of 2D-PAGE at the pre-hatching blastula stage, significant difference of labeled proteins between normal and vegetalized embryos was not observed in the range from neutral to acidic pH, but pls of several proteins were found to be shifted toward alkaline pH. At the mesechyme blastula stage, five major proteins [M.W. 36 K, 43 K (two species), 71 K and 150 K] were enriched in Li⁺-treated embryos among a few hundreds of synthesized proteins. At the late gastrula stage, the labeling intensities of these proteins except for one of 43 K proteins increased remarkably in Li⁺-treated embryos. Furthermore, two proteins (M.W. 105 K and 135 K) were also enriched in Li⁺-treated embryos at this stage. At the prism stage, these proteins enriched in Li⁺-treated embryos became hardly detectable, and the synthesis of at least four proteins (M.W. about 20 K, 41 K, 43 K and 200 K<) appeared to increase in normal embryos, but not in Li⁺-treated embryos. Synthesis of proteins eniched in Li⁺-treated embryos probably support endodermal cell differentiation.     

Synthesis of Collagen-Like Proteins in Embryonic Organs of the Sea Urchin, Hemicentrotus pulcherrimus

In sea urchin embryos exposed to ¹⁴C-proline at 20°C for 3 hr at the gastrula, prism or pluteus stage, ¹⁴C-radioactivity was found in hot acid-extractable proteins, in which more than 4% of the radioactivity was detectable in hydroxyproline residues. In these embryos, ¹⁴C-radioactivity in collagen-like proteins was found in the archenteron, spicule and embryo-wall cells. The rate of synthesis of collagen-like proteins was highest in the archenteron in the mid-gastrula stage, in the embryo-wall cells in the prism stage and in the spicule in the pluteus stage. The rate of synthesis decreased in the archenteron and increased in embryo-wall cells in the period between the mid- and late-gastrula stages, when the rate of synthesis in the spicule was quite low. Thereafter, the rate decreased slightly in the embryo-wall cells, was maintained in archenteron and increased markedly in the spicule. The rates of synthesis of collagen-like proteins are high in these embryonic organs at stages at which development and growth respectively, occur in embryos. Therefore, synthesis of collagen-like proteins probably supports morphogenesis in these embryonic organs.     

Structure of cDNA clones for the small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase from a fern (Asplenium cataractarum rosenstock,aspleniaceae), and its comparison with those of various seed plants

We isolated the small subunit of ribulose-1, 5-bisphosphate carboxylase/oxygenase (RuBisCO SSu) from a fern,Asplenium cataractarum and determined its 34 N-terminal amino acid sequence. We obtained a cDNA clone that contains the entire coding region of the SSu from the same fern species, using synthetic oligonucleotide probes derived from the above amino acid sequence. It contains a 525 bp open reading frame capable of coding for a polypeptide with 174 amino acids, 31 bp 5′-and 206 bp 3′-noncoding regions. It was also elucidated that the precursor to the SSu contains a transit peptide of 53 amino acid residues and a mature protein of 121 residues. We compared the deduced amino acid sequence of the fern SSu with those of 11 other vascular plant species (including gymnosperms, monocots and dicots). As low as 55% homology was observed between those of a fern and seed plants. Constancy of the amino acid substitution rate in RuBisCO SSu was supported by our relative rate test. Amino acid substitution rate per year per site for RuBisCO SSu was calculated to be 0.81×10⁻⁹ assuming that the separation between pteridophytes and seed plants arose 380 million years ago.     

A single amino acid substitution converts cytochrome P450(14DM) to an inactive form, cytochrome P450SG1: complete primary structures deduced from cloned DNAS

Genes for lanosterol 14-demethylase, cytochrome P450(14DM), and a mutated inactive cytochrome P450SG1 were cloned from S. cerevisiae strains D587 and SG1, respectively. A single nucleotide change resulting in substitution of Asp for Gly-310 of cytochrome P450(14DM) was found to have occurred in cytochrome P450SG1. In this protein the 6th ligand to heme iron is a histidine residue instead of a water molecule, which may be the ligand for the active cytochrome P450(14DM). Molecular models of the active sites of the cytochrome P450(14DM) and cytochrome P450SG1 were built by computer modeling on the basis of the known structure of that of cytochrome P450CAM whose crystallographic data are available. The mechanisms which may cause a histidine residue to gain access to the heme iron are discussed.