The seagrass Zostera marina harbors growth-inhibiting bacteria against the toxic dinoflagellate Alexandrium tamarense

Seagrasses are known to have allelopathic activity to reduce growth of phytoplankton. We found growth-inhibiting bacteria (strains E8 and E9) from Zostera marina possessing strong activity against the toxic dinoflagellate Alexandrium tamarense. Strain E9 markedly inhibited growth of A. tamarense even with initial inoculum size as small as 2.9 cells ml^?1. This bacterium also had growth-inhibiting effects on the red-tide raphidophytes Chattonella antiqua and Heterosigma akashiwo, the dinoflagellate Heterocapsa circularisquama, and the diatom Chaetoceros mitra. Small subunit (SSU) ribosomal DNA (rDNA) sequencing analysis demonstrated that the most probable affiliation of these strains was Flavobacteriaceae, and proved that another inhibitory bacterial strain (E8) was the same species as strain E9. Two other bacterial strains (E4-2 and E10), showing different colony color and isolated from the same seagrass sample, revealed no growth-inhibiting activity. Interestingly, strain E4-2 showed the same sequences as E8 and E9 (100 %), and strain E10 matched E8 and E9 with 99.80 % similarity. Growth-inhibiting bacteria against the toxic dinoflagellate Alexandrium tamarense associated with seagrass, such as Flavobacterium spp. E8 and E9, are able to repress shellfish poisoning besides the allelopathic activity of seagrass itself.     

Suppression of feline coronavirus replication in vitro by cyclosporin A

ABSTRACT: The feline infectious peritonitis virus (FIPV) is a member of the feline coronavirus family that causes FIP, which is incurable and fatal in cats. Cyclosporin A (CsA), an immunosuppressive agent that targets the nuclear factor pathway of activated T-cells (NF-AT) to bind cellular cyclophilins (CyP), dose-dependently inhibited FIPV replication in vitro. FK506 (an immunosuppressor of the pathway that binds cellular FK506-binding protein (FKBP) but not CyP) did not affect FIPV replication. Neither cell growth nor viability changed in the presence of either CsA or FK506, and these factors did not affect the NF-AT pathway in fcwf-4 cells. Therefore, CsA does not seem to exert inhibitory effects via the NF-AT pathway. In conclusion, CsA inhibited FIPV replication in vitro and further studies are needed to verify the practical value of CsA as an anti-FIPV treatment in vivo.     

Bromocriptine inhibits salsolinol‐induced prolactin release in male goats

The secretion of prolactin (PRL) is under the dominant and tonic inhibitory control of dopamine (DA); however, we have recently found that salsolinol (SAL), an endogenous DA‐derived compound, strongly stimulated the release of PRL in ruminants. The aim of the present study was to clarify the inhibitory effect of DA on the SAL‐induced release of PRL in ruminants. The experiments were performed from late June to early July. Male goats were given a single intravenous (i.v.) injection of SAL (5 mg/kg body weight (BW)), a DA receptor antagonist (sulpiride, 0.1 mg/kg BW), or thyrotropin‐releasing hormone (TRH, 1 µg/kg BW) before and after treatment with a DA receptor agonist (bromocriptine), and the effect of DA on SAL‐induced PRL release was compared to that on sulpiride‐ or TRH‐induced release. Bromocriptine completely inhibited the SAL‐induced release of PRL (P < 0.05), and the area under the response curve (AUC) for a 120‐min period after the treatment with bromocriptine was 1/28 of that for before the treatment (P < 0.05). Bromocriptine also completely inhibited the sulpiride‐induced release (P < 0.05). The AUC post‐treatment was 1/17 that of pre‐treatment with bromocriptine (P < 0.05). Bromocriptine also inhibited the TRH‐induced release (P < 0.05), though not completely. The AUC post‐treatment was 1/3.8 that of pre‐treatment (P < 0.05). These results indicate that DA inhibits the SAL‐induced release of PRL in male goats, and suggest that SAL and DA are involved in regulating the secretion of PRL. They also suggest that in terms of the regulatory process for the secretion of PRL, SAL resembles sulpiride but differs from TRH.     

Hypoxanthine enhances the cured meat taste

We evaluated the enhancement of cured meat taste during maturation by sensory analysis. We focused on the heat‐stable sarcoplasmic fraction (HSSF) to identify the factors related to cured meat taste. Because the dry matter of HSSF contained more than 30% nitrogen, nitrogen compounds such as free amino acids, small peptides and adenosine triphosphate‐related compounds seemed to be the important components of HSSF. The samples cured with HSSF for 2 h exhibited the same taste profile as ones cured without HSSF for 168 h. Therefore, the changes in the amount and fractions of nitrogen compounds were examined in HSSF during incubation from 0 to 168 h. The concentration of hypoxanthine (Hx) gradually increased, while inosine‐5′‐monophosphate decreased during the incubation. The samples cured with pickles containing various concentrations of Hx were subjected to sensory analysis. The addition of Hx, in a dose‐dependent fashion, enhanced cured meat taste by maturation for 2 h. It was concluded that Hx is essential for the enhancement of cured meat taste.     

Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method for mtDNA typing in hokkaido brown bear (Ursus arctos yesoensis)

To develop an easy method of typing of mitochondrial DNA (mtDNA) in Hokkaido brown bears (Ursus arctos yesoensis), the PCR-RFLP technique was improved using four restriction enzymes: Mbo 1, Cfr 13 I, TspE 1, and Fok 1. This approach identified seven groups of mtDNA haplotypes, HB1/2/5-7, HB 3, HB4, HB8/9, HB10/11, HB12 and HB13 from 102 brown bears of northern, central and eastern Hokkaido.     

Characterization of a monoclonal antibody against desmoplakin 1 for use in dogs

Abstract Skin biopsy specimens from face, axilla, abdomen and thigh, mucocutaneous tissues from anus and vagina, and oral mucosa from six healthy Beagle dogs were examined for desmoplakin (Dsp) immunoreactivity using immunoblotting and immunohistochemical analysis. With immunoblotting using mouse antihuman Dsp 1 monoclonal antibody (DP2.17), a band was detected at 250 kDa in all the extracts as in normal human skin samples, although no band was detected at 210 kDa, suggesting that monoclonal antibody DP2.17 recognizes canine Dsp 1 but not Dsp 2. Moreover, the desmosome regions of all specimens were stained with DP2.17 using immunohistochemical analysis. From these results, DP2.17, developed for the examination of human skin, might be suitable for the investigation of Dsp-related skin disorders in dogs.     

Computed tomography and magnetic resonance imaging of thoracic chordoma in a Bengal tiger (Panthera tigris tigris)

A Bengal tiger was presented for evaluation of weakness, ataxia and inappetance. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a mass extending from the T7-8 vertebral body to the left rib and compressing the spinal cord. On CT, the bone destruction and sequestrum were shown. On MRI, the multilobulated mass appeared hypo- to isointense in T1-weighted and hyperintense in T2-weighted images. The tiger died after imaging, most likely from renal failure. Chordoma without metastasis was diagnosed on necropsy. The imaging characteristics were similar to those found in chordoma in humans. This report describes the use of CT and MRI in an exotic species.     

Relationship between prey utilization and growth variation in hatchery‐reared Pacific bluefin tuna,Thunnus orientalis (Temminck et Schlegel), larvae estimated using nitrogen stable isotope analysis

In mass culture of Pacific bluefin tuna Thunnus orientalis, a marked growth variation is observed after they start feeding at 6–7 mm in body length (BL) on yolk‐sac larvae of other species, and the growth variation in tuna larvae is a factor leading to the prevalence of cannibalism. To examine the relationship between prey utilization and growth variation, nitrogen stable isotope ratios (δ¹⁵N) of individual larvae were analysed. A prey switch experiment was conducted under two different feeding regimes: a group fed rotifers (rotifer fed group), and a group fed yolk‐sac larvae of spangled emperor, Lethrinus nebulosus (fish fed group) from 15 days after hatching (6.87 mm BL). The fish fed group showed significantly higher growth than the rotifer fed group. Changes in the δ¹⁵N of the fish fed group were expressed as an exponential model and showed different patterns from those of the rotifer fed group. The δ¹⁵N of fast‐growing tuna larvae collected in an actual mass culture tank after the feeding of yolk‐sac larvae was significantly higher than those of the slow‐growing larvae, indicating that slow glowing larvae depended largely on rotifers rather than the yolk‐sac larvae.     

Relationships between the first ovulation postpartum and polymorphism in genes relating to function of immunity, metabolism and reproduction in high-producing dairy cows

The decrease in fertility and conception rates of high-producing dairy cows is one of the major negative impacts for today's producers. The recovery of ovarian activity postpartum is affected by the status of immunity, metabolism and reproduction and plays a critical role in subsequent fertility after parturition in the cow. In the present study we investigated the relationships between polymorphisms in genes relating to the above functions and the first postpartum ovulation as a marker of the recovery of ovarian function in the cow. In immune function related-factors, the occurrence of first postpartum ovulation within 3 weeks in the C/C genotypes of tumor necrosis factor α (TNFα) exon (55.4%) and the A/G genotypes of TNFα promoter (55.4%) was significantly higher than that in T/T genotypes of TNFα exon (14.3%) and A/A genotypes of TNFα promoter (14.3%). Moreover, anovulatory cows with the T/T genotype of TNFα exon and the A/A genotype of TNFα promoter tended to have a prolonged days open compared with those of the other genotypes of TNFα polymorphisms. In metabolic function-related factors, ovulatory and anovulatory cows had a different distribution for alleles of the growth hormone receptor, but there were no significant differences in genotype and allele frequency of insulin-like growth factor-I polymorphism. No significant relationships were found between ovarian function after parturition and polymorphisms for reproduction-related genes. In conclusion, polymorphisms of TNFα gene both in exon and promoter regions have a strong association with the early first ovulation within 3 weeks after parturition in the high-producing dairy cow. Taken together, polymorphisms of TNFα gene could be strongly related to early first ovulation after parturition, thus being an effective tool of selection for improving reproductive performance in the high-producing dairy cow.