Secondary erythrocytosis associated with schwannoma in a dog

An 11-year-old, spayed female mixed-breed dog showed clinical signs of right forelimb lameness and pain by palpation around the neck. Radiography and computed tomography (CT) revealed an extradural mass at the 6th and 7th cervical vertebrae, which compressed the spinal cord. The mass was surgically removed and histopathologically diagnosed as schwannoma. The dog recovered her normal gait after hemilaminectomy and removal of the mass. Ten months after the surgery, the tumor recurred with absolute erythrocytosis and was surgically removed again. This removal temporarily resolved the erythrocytosis with a decrease in plasma erythropoietin (EPO) concentration. EPO protein was detected immunohistochemically in the tumor cells. Erythrocytosis in this dog may be caused by ectopic EPO produced in the schwannoma tissues.     

High genetic stability of TM1 and TM2 strains of subtype B feline immunodeficiency virus in long-term infection

To know the genetic changes of feline immunodeficiency virus (FIV) in long-term infection in cats, we inoculated three specific pathogen-free cats with FIV isolates and determined a partial env sequence covering the V3-V5 region. In 2 cats infected with subtype B strains TM1 and TM2, only one amino acid change in region V3 was observed at 9 years post infection (y.p.i.), and no nucleotide substitutions were observed between 9 and 10 y.p.i., indicating that these strains are genetically stable. On the other hand, in a cat infected with subtype A strain Petaluma at 8.7 y.p.i., 3 nucleotide insertions (one amino acid insertion) in region V5, and 1 synonymous nucleotide substitution and 2 non-synonymous nucleotide substitutions in region V5, were observed.     

Synthesis, processing, and subcellular localization of mouse ADAM3 during spermatogenesis and epididymal sperm transport

To elucidate synthesis, processing, and subcellular localization of mouse ADAM3 (cyritestin) during spermatogenesis and epididymal sperm transport, we carried out immunoblotting and immunohistochemical analysis of testicular germ cells, and epididymal and vas deferens sperm, using affinity-purified anti-ADAM3 antibody. ADAM3 was initially synthesized as a 110-kDa precursor in round spermatids, and the precursor was then processed into a 42-kDa mature protein during the sperm transport into and/or once in the epididymis. The mature ADAM3 was localized on the anterior part of capacitated sperm heads and was rapidly removed from the head region during the calcium ionophore A23187-induced acrosome reaction. These results demonstrate that the mature form of ADAM3 is involved in the binding of sperm to the egg zona pellucida, not in the membrane fusion between sperm and egg.     

Genetic profile and serosurvey for virus infections of Japanese wild boars in Shikoku Island

To estimate the genetic background of Japanese wild boars inhibiting the 4 prefectures of Shikoku Island (Kagawa, Tokushima, Kouchi and Ehime), we examined haplotypes of mitochondrial DNA (mtDNA) and genotypes of the nuclear glucosephosphate isomerase-processed pseudogene (GPIP) in 189 wild boars. Of the 8 different mtDNA haplotypes (J5, J10, J12, J13, J15, J19, J20 and E33) detected in Shikoku Island, the first to be identified were J19 and J20 (of Japanese wild boar lineage) and E33 (of European domestic pig lineage). The presence of haplotype E33 indicates local crossbreeding between wild boar and escaped domestic pigs and/or crossbred Inobuta. Four kinds of the GPIP genotypes were detected from 189 wild baors in Shikoku Island, but no European GPIP alleles were found. In 113 wild boars, no antibodies against Classical Swine Fever or Aujeszky's disease were detected, suggesting that they had not been exposed to those pathogens.     

Expression levels of taste‐related genes in palate and tongue tip,and involvement of transient receptor potential subfamily M member 5 (TRPM5) in taste sense in chickens

The elucidation of the mechanisms underlying the taste sense of chickens will contribute to improvements in poultry feeding, because the molecular mechanism of chickens’ taste sense defines the feeding behavior of chickens. Here we focused on the gene expressions in two different oral tissues of chickens – the palate, which contains many taste buds, and the tongue tip, which contains few taste buds. Using the quantitative real‐time polymerase chain reaction method, we found that the molecular markers for taste buds of chickens, that is α‐gustducin and vimentin, were expressed significantly highly in the palate compared to the tongue tip. Our analyses also revealed that transient receptor potential subfamily M member 5 (TRPM5), a cation channel involved in taste transduction in mammals, was also highly expressed in the palate compared to the tongue tip. Our findings demonstrated that the expression patterns of these genes were significantly correlated. We showed that the aversion to bitter solution was alleviated by a TRPM5 inhibitor in behavior of chickens. Taken together, our findings enabled us to develop a simple method for screening taste‐related genes in chickens. The use of this method demonstrated that TRPM5 was involved in chickens’ taste transduction, and that a TRPM5 inhibitor can alleviate chickens’ bitter taste perception of feed ingredients.     

Soil respiration, N2O, and CH4 emissions from an Andisol under conventional-tillage and no-tillage cultivation for 4 years

No-tillage (NT) management is a promising method to sequester soil C and mitigate global warming caused by agricultural activities. Here, we report 4 years of continuous soil respiration rates and weekly nitrous oxide (N₂O) and methane (CH₄) emissions in NT and conventional-tillage (CT) plots in a typical Japanese volcanic soil. Overall, the soil respiration, N₂O emission, and CH₄ uptake decreased significantly in the NT plot. A difference in soil respiration and N₂O emission between the two plots began after the tillage treatment and the incorporation of crop residues and fertilizers, whereas the CH₄ uptake did not vary significantly during the fallow period after the treatments. The N₂O emission was higher from the CT than from the NT plot during the fall. The overall lower CH₄ uptake in the NT than in the CT plot likely resulted from a combination of decreased soil gas diffusivity and higher mineral N content at the soil surface. Higher soil respiration and N₂O emission occurred in the NT plot in the summer of 2003 and were plausibly caused by an increase in the soil moisture content that resulted from lower temperatures during July and August; the higher soil moisture must have accelerated the decomposition of organic matter accumulated in the topsoil. These results indicate that NT management is generally effective for the mitigation of the total GWP by reducing soil respiration and N₂O emission in temperate regions; however, NT management may increase rather than decrease these emissions when fields experience cool summers with frequent rainfall.     

Renal Tubular Cyst Formation in Newborn Rats Treated with p-Cumylphenol

In this study, we investigated the sequential changes in the development of renal tubular cysts in newborn rats treated with p-cumylphenol (PCP). Fifteen animals per sex were treated orally with 300 mg/kg/day of PCP for up to 18 days from postnatal day (PND) 4 and were sacrificed on PNDs 8, 12, 19 and 22 and after a 7 day recovery period. On PNDs 8 and 12, slight dilatation of the collecting ducts was frequently observed in the medulla and slight papillary necrosis was also noted in some cases. These dilated collecting ducts were lined with slightly hyperplastic epithelial cells. On PNDs 19 and 22, multiple large cystic changes arising from the collecting ducts in the outer medulla were seen. These cystically dilated ducts were also lined with hyperplastic epithelial cells. During the dosing period, the labeling index of proliferating cell nuclear antigen in the collecting duct epithelium was higher in the PCP-treated group than in the control group at all time points. After a 7 day recovery period, the cystic change still remained, although the cell density was decreased and the epithelial cells became flattened. On the other hand, basophilic tubules with peritubular lymphoid cell infiltration were multifocally observed in the cortex. In conclusion, PCP induced multiple renal cysts that developed in the collecting ducts of the outer medulla in neonatal rats, and it is suggested that epithelial cell proliferation may play some roles in the induction of cystic lesions.