EFFECT OF IRON DEFICIENCY ON ROOT FERRIC CHELATE REDUCTASE,PROTON EXTRUSION,BIOMASS PRODUCTION AND MINERAL ABSORPTION OF CITRUS ROOT STOCK ORANGE JASMINE (MURRAYA EXOTICA L.)

Three-week iron (Fe) deficiency stress experiments were conducted using two citrus root stocks, Fe-deficiency tolerant Orange Jasmine (OJ, Murraya exotica L.) and the sensitive Flying Dragon [FD, Poncirus trifoliata var. monstrosa (T. Ito) Swingle]. Root ferric chelate reductase activity and proton extrusion increased in OJ between 12 and 18 d of stress, whereas there was no change in FD. Dry weight of OJ roots increased in contrast to FD which decreased. The Mn content in OJ remained the same even under Fe stress. Zn content in OJ roots doubled while that of FD increased 4-folds. The shoot/root Fe accumulation ratio increased in OJ while it decreased in FD. OJ apparently has mechanisms for increasing root biomass, controlling Fe reutilization and regulating manganese (Mn) and zinc (Zn) absorption in response to Fe deficiency. These mechanisms could help maintain homeostasis under heavy metal stress, which would be useful for improved growth of economically important citrus species.     

A scientific alternative to moratoria for rebuilding depleted international tuna stocks

There is considerable international concern and scientific debate about the current state and future of tuna stocks worldwide and the capacity of Regional Fisheries Management Organisations to manage the associated fisheries effectively. In some cases, this concern has extended to predictions of imminent collapse with minimal chances of recovery, even under a commercial catch moratorium. As a viable alternative to a full fishery closure, the Commission for the Conservation of Southern Bluefin Tuna (CCSBT) has adopted a scientifically tested, adaptive rebuilding strategy for the depleted southern bluefin tuna (Thunnus maccoyii) stock. The management procedure (MP) adopted involves a harvest control rule that fully specifies the total allowable catch as a function of key indicators of stock status, adjusting future harvest levels every three years so as to meet the rebuilding targets agreed by CCSBT. It was chosen from a subset of candidate MPs selected following extensive simulation testing. This involved first selecting a wide range of plausible scenarios for stock status and input data, ranging from pessimistic to optimistic, against which the alternative candidate MPs were tested to ensure that they were robust to important uncertainties. This is the first time that a comprehensively evaluated MP has been adopted for an internationally managed tuna stock. Both the process and the outcomes have broad applicability to other internationally managed stocks.     

Spatial and temporal variation in the distribution of juvenile southern bluefin tuna Thunnus maccoyii: implication for precise estimation of recruitment abundance indices

Acoustic tags were used to examine the spatial and temporal distribution of southern bluefin tuna (SBT) in southern Western Australia, which is in a region where fishery-independent acoustic surveys of the recruitment abundance index of SBT have been historically undertaken. We investigated patterns of SBT distribution within and inshore of the acoustic survey area during three summer seasons. Annual differences in distribution patterns were characterized by two distinctive migration pathways. An inshore-migrating pathway was observed in two seasons (2004/2005 and 2006/2007), with a relatively high proportion of tagged SBT (84.5, 65.0%) migrating inshore of the acoustic survey area. The other pathway was concentrated along the shelf (2005/2006 season), with an estimated 63.3% of tagged SBT moving within the survey area. These variable migration patterns may bias the interannual fluctuations in abundance indices. Current survey methods can be modified to include both inshore and continental shelf areas. This contribution shows that the accuracy of acoustic surveys can be improved by including ecological patterns.     

Molecular cloning of a cDNA encoding vitellogenesis-inhibiting hormone in the whiteleg shrimp Litopenaeus vannamei and preparation of its recombinant peptide using an E. coli expression system

The cDNA encoding a precursor of Liv-SGP-G, the most abundant crustacean hyperglycemic hormone-family peptide in the sinus gland of the whiteleg shrimp Litopenaeus vannamei, was cloned by RT-PCR coupled with 5′- and 3′-RACE. The determined cDNA sequence consisted of 621 nucleotides comprising a 69-bp 5′-untranslated region, a 357-bp open reading frame, and a 195-bp 3′-untranslated region. The deduced sequence of 72 amino acid residues corresponding to mature Liv-SGP-G was completely identical to that of natural Liv-SGP-G, determined in our previous study. The recombinant Liv-SGP-G was thereafter heterologously expressed in Escherichia coli, and its vitellogenesis-inhibiting activity in ex vivo cultured ovarian fragments was examined. The recombinant peptides inhibited vitellogenin gene expression with almost the same efficacy as that of natural Liv-SGP-G purified from sinus glands.     

Molecular phylogenetic analysis of bovine papular stomatitis viruses detected in Saga,Japan

In this study, we performed a molecular phylogenetic analysis of six bovine papular stomatitis virus (BPSV) field strains detected from Japanese beef calves kept on a farm in Saga prefecture, a southwest part of Japan, from 2017 to 2020. The phylogenetic analysis based on a partial B2L gene (554-nt) showed that these field strains were divided into two lineages, a lineage (A-lineage) constructed by a Saga strain and strains obtained from various regions of Japan and the world, and other lineage (B-lineage) constructed by five Saga strains and strains obtained from France, USA and Iwate prefecture (a north part of Japan). Furthermore, a Saga field strain named BPSV_SAGAbv2 and strains obtained from USA and Iwate prefecture belonged to a sub-lineage blanched from B-lineage. This is the first report elucidating molecular epidemiological characters of field BPSVs obtained from Saga prefecture. The existence of the multiple lineages was thought to be related to a history of calf introduction from various regions of Japan into Saga prefecture.     

Immunohistochemical and ultrastructural identification of Fusobacterium necrophorum subsp. necrophorum in bovine fatal necrotizing glossitis

A 37-day-old male Japanese black calf showing marked salivation and leucocytosis died and was examined the tissues histologically. Histological lesions were characterized by severe focal necrotic glossitis on the ventral side of the root of the tongue. Immunohistochemically, Fusobacterium necrophorum subsp. necrophorum antigen was detected in the necrotic tissues and its distribution corresponded to that of the gram-negative, nonsporeforming, long filamentous organisms. Ultrastructural similarities between the organism and F. necrophorum subsp. necrophorum, but not subsp. funduliforme were observed. These findings clearly demonstrated that the fatal necrotic glossitis was caused by F. necrophorum subsp. necrophorum. This is the first report of bovine fatal necrotizing glossitis with leucocytosis caused by F. necrophorum subsp. necrophorum infection, and this organism may be an important fatal pathogen in calves with glossal lesions.     

Gastroduodenal adenocarcinomas and rectal adenoma in a cougar (Felis concolor) infected with Helicobacter-like organisms and spirochetes

A 14-year-old female cougar died from gastroduodenal adenocarcinomas and rectal adenoma. At necropsy, polypoid tumor masses of various sizes were scattered on the mucosal surfaces of the stomach, duodenum, and rectum. Histologically, the gastric tumor was diagnosed as an intestinal type adenocarcinoma and the tumor cells metastasized to the mesenteric lymph nodes, spleen, and lung. Helicobacter-like organisms were detected in the lumina lined by foveolar epithelium. In the duodenum, the carcinoma cells were localized in the limina propria and many of them were intensely positive for proliferating cell nuclear antigen (PCNA). In contrast, the rectal adenoma had a lower number of PCNA-positive cells. In the rectum, chronic inflammation with numerous spirochetes was also noted. These results indicated that the occurrence of the gastrointestinal tumors might be associated with the bacterial infection described above.     

Bacteriological evaluation of composted manure solids prepared from anaerobic digested slurry for hygienic recycled bedding materials for dairy cows

Changes in mastitis‐causing pathogens, pH and water content in composted manure solids (CMS) prepared from digested slurry were evaluated during turning at 2‐day intervals for 8 days (C1–C4). The numbers of streptococci, coagulase‐negative staphylococci and coliforms were 2.6 × 10¹, 1.7 × 10² and 1.0 × 10¹ colony‐forming units (cfu)/g in CMS (C4) (summer), and these counts were markedly lower (P < 0.05) than those in CMS (C0 and C1). The bacterial counts ranged from 10¹ to 1.7 × 10² cfu/g in CMS (C4) (summer) and were within approved levels, <1 × 10⁶ cfu/g, indicating a minimal mastitis risk. The temperatures in CMS (C1–C4) increased to 63°C–74°C in summer and 67°C–70°C in winter. The mean pH values in CMS (C0–C4) were 9.2 in summer and 8.7 in winter, and water contents ranged from 61.7% to 69.6% in summer and 73.2% to 66.2% in winter. The significant decrease of pathogenic bacteria in CMS appears to be closely related to temperature >63°C for 8 days, pH 8.7–9.2, and water content 62% to 73%. This study demonstrates that prepared CMS has value as a recycled material with the potential to alleviate udder health issues in dairy cows.     

Brewer's yeast efficiently degrades phytate phosphorus in a corn-soybean meal diet during soaking treatment

Microbes such as yeast and Aspergillus are known to produce phytase, and Aspergillus phytase has been used as a feed additive for improving phytate-phosphorus bioavailability in monogastric animals. We measured phytase activity in some by-products from fermented food and beverage productions by yeast and Aspergillus . The phytase activity was as high as 3577 and 2225 PU/kg DM in raw and dried brewer's yeasts, respectively. On the other hand, the phytase activity was approximately 400 PU/kg DM in white-wine yeast and red-wine yeast. The phytase activity was further low in natto (fermented soybean) residue, soy sauce cake, rice brewer's grain and the activity was not detected in dried corn-barley distiller's grain with soluble and sweet-potato distiller's residue. The stability of phytase against pepsin was much lower in the brewer's yeast than in an Aspergillus phytase preparation. On the other hand, the addition of raw brewer's yeast effectively degraded phytate phosphorus in a corn-soybean meal diet during soaking. These results suggest that phytase in the examined by-products is not suitable for the phytase source of conventional diets, but that the soaking treatment with a raw brewer's yeast is an alternative method for improving phytate-phosphorus bioavailability in corn-soybean meal diets for pigs.     

An outbreak of teat papillomatosis in cattle caused by bovine papilloma virus (BPV) type 6 and unclassified BPVs

Out of 700 heifers at a local farm in Hokkaido, the Northern island of Japan, 560 (80%) were found to have benign teat tumors. All of the analyzed tumors were macroscopically of the flat-and-round type, and no other types such as rice-grain or frond epithelial type were found. The lesions were characterized by epithelial hyperplasia, acanthosis and hyperkeratosis. Unlike in typical fibropapilloma, fibroplasia of the underlying dermis was not observed. Bovine papilloma virus (BPV) capsid antigen and virus particles were found in basophilic intranuclear inclusions of the stratum granulosum of the epidermis by immunohistochemistry and electron microscopy, respectively. BPV-specific DNA was also detected in the lesions. By means of the polymerase chain reaction (PCR) and DNA sequencing of the PCR products, the viruses causing this outbreak were identified mainly as BPV-6 (64%), partly as unclassified BPVs (14%) and their co-infections (21%). Our findings suggest that this outbreak of benign teat tumors was associated with several BPV types.