Den distribution and den use by the red foxVulpes vulpes japonica in Kyushu

The distribution of dens and den use by the red fox was studied in Kumamoto Prefecture between 1968 and 1982. A total of 80 dens were classified into natal, residential, and temporarily-visited dens. Natal dens comprised 12.4% of all dens. Relative proportions were quite stable for a long period. This indicates a constant number of reproducing females in the area for a considerable length of time. Seasonally the utilization of den showed three peaks in February, May and October. The peaks coincided well with the peaks of reproductive activity of female foxes. The results of multiple regression analysis of distribution of dens with respect to selected environmental parameters around densites indicated that the fox selectively utilize open land, rather than densely vegetated areas. The persistence of dens, the selective utilization by foxes of open land and the sizes of dens were all related to the breeding activities of female foxes inhabiting the area. Reproductive females usually used plural dens (“den group”) in one reproductive season. The numbers of those females occuring in the area were maintained at a steady level for fairy long periods. These indicate that the existence of a stable social relationship between females mediated through occupancy of “den groups.”     

Genome type analysis of adenovirus type 4 isolates, recently obtained from clinically different syndromes in some areas in Japan

DNA cleavage analyses with EcoRI, HindIII and BamHI were carried out to investigate genome types of recent Ad 4 isolates obtained from acute respiratory disease (8 strains), and ocular disease (11 strains) in Japan. DNA cleavage patterns of all 19 isolates studied were identical regardless of whether they were recovered from respiratory tract or conjunctiva, but were distinct from that of the prototype strain.     

Molecular epidemiology of adenovirus type 8 (Ad 8) in Taiwan: four subtypes recovered during the period of 1980-1981 from patients with epidemic keratoconjunctivitis

Adenovirus type 8 (Ad 8) has been the major and important causative agent of epidemic keratoconjunctivitis (EKC). By enzymatic cleavage analysis with five endonucleases, PstI, HindIII, BamHI, SalI and SstI, 27 out of 149 Ad 8 isolates recovered from patients with EKC during the period from July, 1980 to July, 1981 in Kaohsiung, Taiwan, were studied. By cleavage patterns, 27 Ad 8 isolates in Kaohsiung were classified into four subtypes which were found to be different from the subtypes (Ad 8A, Ad 8B) prevalent in Sapporo (1).     

In vivo and in vitro synergistic antitumor effect of interleukin-2-cultured tumor-bearer spleen cells and immune fresh spleen cells

Summary The synergistic antitumor effect of interleukin-2(IL-2)-cultured tumor-bearer spleen cells (cultured lymphocytes) and immune fresh spleen cells was examined. Tumor-bearer cultured lymphocytes were obtained by culturing BALB/c spleen cells from syngeneic MOPC104E-tumor-bearing mice for 11 days with crude IL-2 and a soluble tumor extract. These cultured lymphocytes had weak antitumor activity when transferred i.p. into tumor-bearing mice that had been inoculated i.p. with 10⁵ tumor cells 5 days previously. Immune fresh spleen cells, obtained from mice in complete remission after the treatment with cyclophosphamide, also had weak antitumor activity when transferred at the same schedule. The cultured cells and the fresh cells, mixed together before transfer, significantly augmented the therapeutic effect. At least 1×10⁷ tumor-bearer cultured lymphocytes and 4×10⁷ immune cells were needed for the synergistic effect. A tumor-specific combination was needed for both cultured and fresh cells. The effective subpopulation of tumor-bearer cultured lymphocytes was a cytotoxic one from an Lyt2⁺ precursor, and that of the immune fresh spleen cells was noncytotoxic, Lytl⁺ and Lyt2⁺ T-cells.A similar synergistic effect was also observed during in vitro coculture of tumor-bearer and immune cells. Cytotoxicity, as assessed by the ⁵¹Cr-release test, of tumor-bearer IL-2-cultured lymphocytes was maintained most effectively after 3 or 4 days of culture without IL-2 when the lymphocytes were cocultured with immune fresh spleen cells and tumor cells.     

Interconversion of polyamines in wild-type strains and mutants of yeasts and the effects of polyamines on their growth

Yeasts of wild-type strains, such as Saccharomyces cerevisiae, Schizosaccharomyces pombe and Candida albicans were shown to have the ability to form aminopropylcadaverine and aminopropylhomospermidine from cadaverine and homospermidine, respectively. A polyamine autotroph S. cerevisiae 179-5, which lacks ornithine decarboxylase, produced both aminopropylcadaverine and aminopropylhomospermidine, while another mutant S. cerevisiae Y 260 A, which lacks spermine synthase, formed only aminopropylcadaverine. Naturally-occurring triamines and tetraamines except norspermidine and norspermine stimulated the growth of S. cerevisiae 179-5. All the six aliphatic diamines with carbon chain length ranging from one to six were effective in activating the growth of S. cerevisiae 179-5, though all of them were not converted to either triamines or tetraamines.     

Hormonal induction of all stages of spermatogenesis in germ-somatic cell coculture from immature Japanese eel testis

In cultivated male eel, spermatogonia are the only germ cells present in testis. Our previous studies using an organ culture system have shown that gonadotropin and 11-ketotestosterone (11-KT, a potent androgen in teleost fishes) can induce all stages of spermatogenesis in vitro. for detailed investigation of the control mechanisms of spermatogenesis, especially of the interaction between germ cells and testicular somatic cells during 11-KT-induced spermatogenesis in vitro, we have established a new culture system in which germ cells and somatic cells are cocultured after they are aggregated into pellets by centrifugation. Germ cells (spermatogonia) and somatic cells (mainly Sertoli cells) were isolated from immature eel testis. Coculture of the isolated germ cells and somatic cells without forming aggregation did not induce spermatogenesis, even in the presence of 11-KT. In contrast, when isolated germ cells and somatic cells were formed into pellets by centrifugation and were then cultured with 11-KT for 30 days, the entire process of spermatogenesis from premitotic spermatogonia to spermatozoa was induced. However, in the absence of 11-KT in the culture medium spermatogenesis was not induced, even when germ cell and somatic cells were aggregated. These results demonstrate that physical contact of germ cells to Sertoli cells is required for inducing spermatogenesis in response to 11-KT.     

In situ hybridization to metaphase chromosomes in six species ofPhaseolus andVigna using ribosomal DNA as the probe

In situ hybridization with a biotin-labeled rice ribosomal DNA (rDNA) probe to the somatic metaphase chromosomes of six species ofPhaseolus andVigna (P. angularis, P. calcaratus, P. coccineus, P. vulgaris, V. sesquipedalis andV. sinensis) was done to determine the sites of rDNA. Hybridization signals were present in the terminal and subterminal chromosome regions of each of the six species. The number of rDNA sites was two inP. angularis andP. calcaratus, four inP. coccineus andP. vulgaris, and six inV. sesquipedalis andV. sinensis.     

W-heterochromatin of chicken; its unusual DNA components,late replication,and chromatin structure

About 65% of DNA in the chicken W chromosome has been shown to consist ofXhoI andEcoRI family repetitive sequences. These sequences showed remarkable delay in the electrophoretic mobility at low temperature on a polyacrylamide gel. Three dimensional structures of the 0.7-kbXhoI and the 1.2-kbEcoRI family repeating units were estimated to be irregular solenoids using a computer program based on wedge angles of all the 16 dinucleotide steps. Fluorescencein situ hybridization demonstrated that these two family sequences were localized in a major heterochromatic body in an interphase nucleus. Incorporation of bromodeoxyuridine into the W chromosome in the synchronous culture of MSB-1 cells occurred about 1 h later than the peak of S phase. The chromatin structure formed alongXhoI andEcoRI family sequences was suggested to be different from the total chromatin or chromatin containing the β-actin gene sequence in that the linker DNA lengths of the former were significantly longer. Fractionation of theHaeIII-digested MSB-1 nuclei yielded a chromatin fraction in whichXhoI family sequences were partially enriched. Several DNA-binding proteins showing higher affinity for theXhoI family sequence were present in this fraction.     

Stable transformation of cultured cells of the liverwortMarchantia polymorpha by particle bombardment

Suspension-cultured cells (A-18 line) of the liverwortMarchanta polymorpha were bombarded by a pneumatic particle gun with plasmid pCH harbouring the hygromycin phosphotransferase (HPT) gene (hpt) under the control of the cauliflower mosaic virus (CaMV) 35 S promoter and the nopaline synthase polyadenylation region. Nine weeks after bombardments, 128 hygromycin-resistant calluses were obtained from an approximate total of 7×10⁶ cells. Ten cell lines chosen randomly were analysed further. Southern blot analysis showed that all of the ten lines contain thehpt gene in the genome, demonstrating that these lines are transformants. An HPT enzyme activity assay confirmed the expression of the gene in all of the transformant lines.