DNA transposon fossils present on the conditionally dispensable chromosome controlling AF-toxin biosynthesis and pathogenicity of Alternaria alternata

The strawberry pathotype of Alternaria alternata produces host-specific AF-toxin and causes Alternaria black spot of strawberry. Previously, we isolated cosmid clones pcAFT-1 and pcAFT-2 from strain NAF8 of the strawberry pathotype that contain AF-toxin biosynthetic genes, named AFT genes. In a molecular characterization here of pcAFT-1 and pcAFT-2, 11 AFT genes and five transposon-like sequences, named TLS-S1 to TLS-S5, were detected. The nucleotide sequences of TLS-S1 and TLS-S4 share high homology, and their putative products have similarity to transposases of the hAT family transposons. Thus, TLS-S1 and TLS-S4 were renamed TLS-S1-1 and TLS-S1-2, respectively. Amino acid sequences deduced from TLS-S2, TLS-S3, and TLS-S5 have similarity to transposases of the Fot1/Pogo family transposons, but they are significantly different. All five sequences have incomplete open reading frames (ORFs) for transposases owing to deletions, termination codons, and/or frameshifts, indicating that they are inactivated elements. Analysis of genomic distribution of these sequences revealed that they are specifically distributed on a 1.05-Mb chromosome of NAF8, which has been identified as a conditionally dispensable (CD) chromosome encoding AFT genes. The presence of three, four, and three copies of TLS-S1, TLS-S2, and TLS-S3, respectively, and a single copy of TLS-S5 on the CD chromosome were estimated by DNA gel blot analysis. The remaining copy of TLS-S1 and the three copies of TLS-S2 were isolated and identified to also encode incomplete ORFs. Thus, it appears that all copies of the transposon-like sequences identified are inactivated elements (fossils) unique to the CD chromosome in the genome of the strawberry pathotype. The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under the accession numbers AB236733 (TLS-S1-1), AB236734 (TLS-S1-2), AB236735 (TLS-S1-3), AB236736 (TLS-S2-1), AB236737 (TLS-S2-2), AB236738 (TLS-S3), and AB236739 (TLS-S5)     

Mycoplasma ovis detected in free-living Japanese serows, Capricornis crispus

Nineteen blood samples collected from free-ranging wild Japanese serows, Capricornis crispus, between 2006 and 2008 in Iwate prefecture were examined for the hemoplasma infection by real-time PCR targeting the 16S rRNA gene. Five (26.3%) out of the 19 samples were positive in real-time PCR with an average melting temperature at 85.18 °C. The positive samples in the real-time PCR were reconfirmed by conventional PCR, and one of them was successful for direct DNA sequencing. The nucleotide sequence of the 16S rRNA gene of the representative stain was identical to that of Mycoplasma ovis. This was the first demonstration of hemotropic mycoplasma infections among the free-living Japanese serows in Japan.     

Two genetic clusters in swine hemoplasmas revealed by analyses of the 16S rRNA and RNase P RNA genes

Only two hemoplasma species, Eperythrozoon parvum and Mycoplasma suis, have been recognized in pigs. Here we demonstrate the genetic variations among six hemoplasma strains detected from pigs, by analyzing the 16S rRNA and RNase P RNA (rnpB) genes, and propose a novel hemoplasma taxon that has not been described previously. Phylogenetic trees based on the nucleotide sequence of the 16S rRNA gene indicated that these six hemoplasmas were divided into two clusters representing M. suis and a novel taxon. We further examined the primary and secondary structures of the nucleotide sequences of the rnpB gene of the novel taxon, and found it distinct from that of M. suis. In conclusion, we unveiled a genetic cluster distinct from M. suis, suggesting a new swine hemoplasma species or E. parvum. Our findings also suggest that this novel cluster should be included in the genus Mycoplasma.     

Effect of continuous compost application on water-stable soil macroaggregation in a field subjected to double cropping

The influence of continuous application of compost and fertilizer on soil macroaggregation in a field subjected to long-term (ca. 20 years) double cropping (rice and barley) was investigated. Soil samples were collected from 4 different plots: a) No-NF, fertilizer containing P and K but no N; b) F, fertilizer containing N, P, and K; c) F+ LC, fertilizer plus low rate of compost; and d) F+ HC, fertilizer plus high rate of compost. The application of compost and fertilizer increased the degree of macroaggregation (>0.25 mm), the contents of organic C, total N, hydrolyzable carbohydrates, and dithionitecitrate-bicarbonate (DCB) soluble Al, and the hyphal length in the order of No-NF<F<F+LC<F+HC plots. The degree of macroaggregation showed high correlation coefficients (r ≥ 0.95) with the contents of organic and inorganic components or the hyphal length. Most of these properties were strongly intercorrelated among themselves. The results obtained in this study suggest that organic matter including polysaccharides, active Al, and hyphae play an important role together in soil macro aggregation in the field subjected to double cropping under study.     

Growth characteristics, stress-wave velocity, and Pilodyn penetration of 15 clones of 12-year-old Tectona grandis trees planted at two different sites in Indonesia

Tree improvement programs for teak (Tectona grandis) have mainly focused on breeding of trees with superior growth characteristics. However, improvement in wood quality should be included in breeding programs for high yield and high quality timber. In the present study, growth characteristics [stem diameter (D), tree height (H), and bole volume (V)], stress-wave velocity (SWV), and Pilodyn penetration (Py) were measured for 15 clones of 12-year-old teak trees planted at two different sites in Indonesia to clarify the variations in tree growth characteristics, SWV, and Py among clones, their repeatability, interaction between genotype and environment, and correlations between measured characteristics. Significant differences of all measured characteristics were found among 15 clones at both sites. Their repeatability showed relatively moderate to high values in both sites. These results indicate that these characteristics are closely related to genetic factors. Significant interaction between genotype and environment was found in all measured characteristics. In addition, SWV and Py showed lower interaction between genotype and environment than growth characteristics. No significant correlation was found between growth characteristics and SWV. These results suggest that wood properties and growth characteristics of teak trees can be improved by application of an appropriate tree breeding program.     

Possible Role of ZPAC,Zygote-specific Proteasome Assembly Chaperone,During Spermatogenesis in the Mouse

In the mammalian testis, the ubiquitin-proteasome system plays important roles in the process that promotes the formation of mature sperm. We recently identified zygote-specific proteasome assembly phaperone (ZPAC), which is specifically expressed in the mouse gonads and zygote. ZPAC mediates a unique proteasome assembly pathway in the zygote, but the expression profile and function of ZPAC in the testis is not fully understood. In this study, we investigated the possible role of ZPAC during mouse spermatogenesis. First, we analyzed the expression of ZPAC and 20S proteasome subunit α4/PSMA7 in the adult mouse testis. ZPAC and α4 were expressed in spermatogonia, spermatocytes, and round spermatids. In elongating spermatids, ZPAC was expressed until step 10, whereas expression of α4 persisted until step 12. We then examined the expression profile of ZPAC and α4 in a mouse model of experimental unilateral cryptorchidism. Consistent with appearance of morphologically impaired germ cells following cryptorchidism, the ZPAC protein level was significantly decreased at 4 days post induction of experimental cryptorchidism (D4) compared with the intact testis, although the amount of α4 protein persisted at least until D10. Moreover, intense ZPAC staining was co-localized with staining of annexin V, an early indicator of apoptosis in mammalian cells, in germ cells of cryptorchid testis, but ZPAC was also expressed in germ cells showing no detectable expression of annexin V. These results suggest that ZPAC plays a role during spermatogenesis and raises the possibility that 20S proteasome mediated by ZPAC may be involved in the regulation of germ cell survival during spermatogenesis.     

A case report of RccHanTM: WIST rat with multiple neoplastic and non-neoplastic proliferative lesions

It is extremely rare to have multiple spontaneous proliferative lesions in young adult rats. Here, we report the occurrence of different proliferative lesions in multiple tissues of a 7-week-old female rat in a 1-week repeated toxicity study. Grossly, multiple white patches and nodules in the bilateral kidneys, femoral and subcutaneous masses, and a nodule in the liver were observed. Renal lesions were diagnosed as renal mesenchymal tumors. One of the femoral subcutaneous masses was diagnosed as an adenolipoma consisting of mammary epithelial cells and mature adipocytes. The other femoral and abdominal subcutaneous masses were diagnosed as lipomas consisting of mature adipocytes. The liver nodule was diagnosed as non-regenerative hepatocellular hyperplasia, which was characterized by the proliferation of slightly hypertrophic hepatocytes. In the cauda equina, the growth of enlarged Schwann cells around the axon was observed, and this lesion was diagnosed as a neuroma.     

The effects of antipyretics on influenza virus encephalitis in mice and chicks

To investigate the effect of antipyretics on the murine and poultry models of influenzal encephalitis, we injected large quantities of antipyretics, acetylsalicylic acid (aspirin) and dicrofenac sodium (voltaren). The effect of antipyretic treatment on the murine encephalitis model was unremarkable histologically and immunohistochemically. Whereas in chicks, CNS lesions consisting of perivascular cuffing and gliosis appeared only in those animals treated with the antipyretics and viral antigen was detected mainly in the nuclei of glial cells or vascular endothelia of voltaren-treated animals. We here demonstrate that antipyretic treatment aggravated the hematogenous spread of the influenza virus to the CNS in chicks, but did not affect the transneural infection in mice.