Allelopathy of pinecone in Japanese red pine tree (Pinus densiflora Sieb. et Zucc.)

There are fewer weeds in the ground covered with pinecones of Japanese red pine trees ( Pinus densiflora Sieb. et Zucc.) than in the ground without pinecones. When six species of seeds were cultured with Japanese red pinecones on agar, the growth of cress, lettuce and cat's eye were inhibited. Pinecones had a plant species-selective influence on their growth. Exudates of the pinecones showed high biological activity and also plant species-selective activity. Some species-selective allelopathic substances may be released from the pinecones. One of the inhibiting allelopathic substances was isolated from the exudates of the pinecones using a bioassay of cat's eye. The substance was identified as phenylacetic acid from an ESI-MS and ¹H NMR spectra. It inhibited shoot and radicle elongation of cat's eye at concentrations of 30–100 p.p.m. The substance was also isolated from an agar medium after removal of the pinecones. These results suggest that pinecones may inhibit some weeds that grow around pine trees. There are many reports of the allelopathic effect of leaves, bark and roots of many plants, however, this is the first report that reveals the cone also affects the allelopathy phenomenon in Japanese red pine trees.     

Functional Analysis of an ATP-Binding Cassette Transporter Gene in Botrytis cinerea by Gene Disruption

The BMR1 gene encoding an ABC transporter was cloned from Botrytis cinerea. To examine the function of BMR1 in B. cinerea, we isolated BMR1-deficient mutants after gene disruption. Disruption vector pBcDF4 was constructed by replacing the BMR1-coding region with a hygromycin B phosphotransferase gene (hph) cassette. The BMR1 disruptants had an increased sensitivity to polyoxin and iprobenfos. Polyoxin and iprobenfos, structurally unrelated compounds, may therefore be substrates of BMR1. Received 18 December 2000/ Accepted in revised form 18 April 2001     

Basic characterization of 90 kDa heat shock protein genes HSP90AA1, HSP90AB1, HSP90B1 and TRAP1 expressed in Japanese quail (Coturnix japonica)

In the current study, we describe four novel members of the 90 kDa heat shock protein (HSP90) family expressed in Japanese quail, Coturnix japonica. The coding regions of the genes, CjHSP90AA1, CjHSP90AB1, CjHSP90B1 and CjTRAP1, exhibited more than 94% similarity to their related genes in chicken. The putative proteins encoded by these quail genes contained motifs considered essential for HSP90 gene function. In addition, the predicted proteins were more similar to HSP90AA1, HSP90AB1, HSP90B1 and TRAP1 proteins expressed in vertebrates than they were to other members of the HSP90 family. Exon numbers of CjHSP90AA1 (11), CjHSP90AB1 (12) or CjTRAP1 (18) are the same as the chicken and mammalian orthologs. Furthermore, gene order in the regions surrounding CjHSP90AB1 and CjTRAP1 has been preserved, providing evidence that the genomic regions were orthologous to HSP90‐containing regions in the chicken genome. The promoter regions of the genes also contained conserved motifs identified in related genes of chicken. However, the nucleotide sequences of the 5′‐flanking region of these genes were highly polymorphic. We also found that CjHSP90AA1 exhibited a robust response to heat shock treatment. Taken together, the data suggest that CjHSP90AA1, CjHSP90AB1, CjHSP90B1 and CjTRAP1 encode orthologs of HSP90AA1, HSP90AB1, HSP90B1 and TRAP1, respectively.     

Characteristics of Biceps femoris and Longissimus thoracis muscles of five cattle breeds grown in a feedlot system

Our experiment was conducted to study physical quality and chemical composition of meat of Angus (A), Hereford (H), Friesian Holstein (FH), Australian Commercial Cross (ACC) and Murray Grey (MG) cattle breeds grown in a feedlot system. Significant differences were observed among five cattle breeds for cooking loss, tenderness, fatty acid composition, collagen and cholesterol content of meat. However, pH, water‐holding capacity, water, ash, fat and crude protein contents were not different. Cholesterol content of meat of A and FH was lower (P < 0.01) than that of H, ACC and MG. Acidity (pH), cooking loss, shear force, water, ash, crude protein, collagen and cholesterol content of Biceps femoris muscle were higher than those of Longissimus thoracis muscle, but water‐holding capacity and fat content were lower. Unsaturated fatty acid content of Biceps femoris muscle was higher (P < 0.01) than that of Longissimus thoracis. In conclusion, the differences among cattle breeds had a great effect on cooking loss, shear force, collagen, fatty acid composition and cholesterol of meat, but had little effect on water‐holding capacity, pH and proximate composition of meat. The meat of Hereford cattle was the best quality, because of the lowest shear force, cooking loss and collagen. Longissimus thoracis muscle was relatively better in cooking loss, tenderness and collagen content than Biceps femoris muscle.     

Identification and morphological characteristics of dental neonatal line in sika deer (Cervus nippon)

The dental neonatal line of the sika deer (Cervus nippon) was identified experimentally using chronological labeling methods. In the enamel, prominent dark lines were observed under transmitted light, and the number of increments between the dark line and labeling line was almost consistent with the day-age at the time of labeling injection. Therefore, we identified the dark line as the enamel neonatal line. In the dentin, the bright line was observed under polarized light. Since the bright line corresponded to the enamel neonatal line, we recognized the bright line as the dentin neonatal line. Neonatal lines intersected with the enamel-dentin junction at approximately one-third cervical in the first molar. Using these features, it would make possible to distinguish the neonatal line in wild sika deer.     

Serological evidence of influenza A virus infection in Kuril harbor seals (Phoca vitulina stejnegeri) of Hokkaido, Japan

For proper management and conservation of the Kuril harbor seal (Phoca vitulina stejnegeri) through disease control, serological analysis was performed for influenza A virus infection in free-ranging seals in Hokkaido, Japan. Serum samples were collected from seals at Nosappu (231 seals), Akkeshi (16) and Erimo (75), between 1998 and 2005, and were analyzed by ELISA. Antibodies to the influenza A virus were detected only in seals from Nosappu. The incidences were 11% (1/9), 3% (2/66), 12% (7/59) and 6% (5/77) in 1998, 2003, 2004 and 2005, respectively. These suggest sporadic infection. Because antibody-positive seals included juvenile seals in each year, the infections were considered to have been circulated since no later than the late 1990s until recent years. ELISA-positive sera were analyzed by hemagglutination inhibition (HI) tests to determine the subtypes. Antibodies to the H3 and H6 subtypes were detected in 10 and 2 sera, respectively. Two of the sera that had antibodies to the H6 subtype also had antibodies to the H3 subtype. These two seals were considered to have been infected with both the H3 and H6 subtypes. This is the first investigation to find antibodies to the H6 subtype in seals. Although the H6 subtype had been isolated only from avians, genetic analysis had suggested that the H6 subtype could become a novel mammalian pathogen. For definitive diagnosis, detection of the virus from the tissue or mucus of seals is required.