Daily incremental lines in sika deer (Cervus nippon) dentine

This work was designed to observe the dentine incremental lines of the sika deer (Cervus nippon) fawns and to investigate their periodicity using the chronological labeling method with fluorochromes. The incremental lines were observed in decalcified specimens stained by Bodian's silver technique, and the fluorescence-labeled lines were observed in undecalcified and ground specimens. In the silver stained specimens, there were two types of lines, deeply stained thick lines and faintly stained minute regular incremental lines. The intervals and staining intensities of the deeply stained thick lines were very similar to those of the fluorescence-labeled lines in the ground specimens obtained from the same tooth, and hence, it appeared that the both lines were identical. The number of minute incremental lines between the deeply stained thick lines was the same as that of days between the time when each fluorescent labeling injection was made. Therefore, it seemed that each minute incremental line was formed each day. The possibility of age estimation in days using diurnal dentine increments was discussed.     

Evaluation of in vitro and in vivo inhibitory effects of fusidic acid on Babesia and Theileria parasites

Fusidic acid known to has antibacterial, antifungal, and antimalarial activities. Fusidic acid blocks translation elongation factor G gene in Plasmodium falciparum. In the present study, the inhibitory effects of fusidic acid on the in vitro growth of bovine and equine Babesia parasites were evaluated. The inhibitory effect of fusidic acid on the in vivo growth of Babesia microti was also assessed. The in vitro growth of four Babesia species that were tested was significantly inhibited (P < 0.05) by micromolar concentrations of fusidic acid (IC₅₀ values = 144.8, 17.3, 33.3, and 56.25 μM for Babesia bovis, Babesia bigemina, Babesia caballi, and Theileria equi, respectively). Combinations of fusidic acid with diminazene aceturate synergistically potentiated its inhibitory effects in vitro on B. bovis and B. caballi. In B. microti-infected mice, fusidic acid caused significant (P < 0.05) inhibition of the growth of B. microti at the dose of 500 mg/kg BW relative to control group. These results indicate that fusidic acid might be incorporated in treatment of babesiosis.     

Frequencies of the M918I mutation in the sodium channel of the diamondback moth in China, Thailand and Japan and its association with pyrethroid resistance

In addition to the allele frequencies of the L1014F and T929I mutations which are involved in nerve-insensitive resistance to a pyrethroid, those of the M918I mutation were examined using field strains obtained in China, Thailand, and Japan during 2009-2011. Results show that the resistance allele frequencies at the L1014F site were 89-100%, 97-100% and 65-85%, respectively, for strains in China, Thailand, and Japan. The respective allele frequencies at the T929I site were 86-100%, 70-97% and 58-84% for Chinese, Thai, and Japanese strains. With low frequencies up to 27%, M918I was found in Japan and China, but not in Thailand. The strain homozygous for the M918I and L1014F mutations was established and its resistance level to a pyrethroid was examined. The strain lacks a portion of the sodium channel gene corresponding to the 3′ portion of exon 18a, intron 18, and the 5′ portion of exon 18b. Nevertheless, the strain showed a similar level of resistance to that which was homozygous for the T929I and L1014F mutations.     

Regression tree analysis of the relationship between the concentrations of antimicrobial components and the microbiota of normal milk from dairy cows

The purpose of this study was to determine the concentrations of antimicrobial components (immunoglobulin A (IgA), lactoferrin (LF), lingual antimicrobial peptide (LAP), and S100A7) in normal milk and their relation to host factors (Age, somatic cell count (SCC), days in milk, richness, and alpha diversity of the milk microbiota) in dairy cows using multivariate regression tree analyses, and to clarify how the milk microbiota is related to the obtained results. Thirty normal milk samples were collected from a commercial dairy farm in June 2020. The thresholds that predicted the concentration of each antimicrobial component in milk were obtained by regression tree analysis, and the beta-diversity of the milk microbiota composition between groups divided according to each threshold was compared by an analysis of similarities test. The IgA and LF concentrations were mainly predicted by the SCC (177,500 and 70,000 cells/ml, respectively), and the LAP and S100A7 concentrations were predicted by Age (29.667 and 40.3 months, respectively). No relationship was observed between the concentration of IgA, LAP, or S100A7 and the milk microbiota composition between the groups divided by the threshold for prediction, but the milk microbiota composition was significantly different between the groups divided by the threshold for predicting the LF concentration. Our results indicated that the LF concentration in normal milk may be associated with the milk microbiota composition.     

Survey on wild rodents for endoparasites in Iwate Prefecture, Japan

Wild rodents (58 Apodemus speciosus, 29 A. argenteus and 7 Microtus montebelli) were surveyed for endoparasites in Iwate Prefecture, Japan, from October to December 1995 and from April to October 1996. Two trematodes (Echinostoma macrorchis, Plagiorchis muris), 4 or more cestodes (Hymenolepis diminuta, Raillietina coreensis, Cladothyridium spp., Cysticercus fasciolaris), 12 nematodes (Carolinensis minutus, Eucoleus sp., Heligmosomoides kurilensis, H. protobullosus, H. speciosus, Heterakis spumosa, Rhabditis (Pelodera) orbitalis, Rictularia cristata, Syphacia emileromani, S. frederici, S. montana, Trichuris sp.) and 3 protozoans (Giardia sp., Trichomonas sp., Trypanosoma sp.) were identified. The two species of Apodemus were similar to each other, but they were extremely different from M. montebelli in parasite fauna.     

剪股颖属植物遗传分化及系统关系的分子标记研究

剪股颖属植物形态变异大、倍性复杂、种间易于杂交,导致异名多、分类混乱。本研究采用4种分子标记技术,对包括匍茎剪股颖、巨序剪股颖及红顶草在内的7种剪股颖,共58个个体的遗传分化和系统关系进行研究。根据谱带清晰程度及多态性,筛选出9个RAPD引物、2个SSR引物、5个ISSR引物及1个SCAR标记,并建立了最适的PCR反应条件。采用最大简约法和距离法对7种剪股颖植物进行系统树分析,并用靴带检验法计算内部分支的支持率。启发式搜索得到的简约树和由UPGMA方法得到的表征树近乎相同,其中,匍茎剪股颖和红顶草构成单系类群并得到100%的置信支持。红顶草显示了匍茎剪股颖特异性特征谱带,但同时具有不同于匍茎剪股颖的遗传分化,支持将红顶草视为匍茎剪股颖一个变种的观点。对匍茎剪股颖与巨序剪股颖间的遗传分化进行了探讨。     

Passive protection of dogs against clinical disease due to Canine parvovirus-2 by specific antibody from chicken egg yolk

The protective effect of immunoglobulins derived from chicken egg yolk (IgY) against infection by Canine parvovirus 2 (CPV-2) was evaluated in 10 beagle dogs orally challenged with a strain of the virus. The 2-mo-old dogs were divided into 3 groups and treated with powders containing CPV-2 IgY or normal egg yolk for 7 d after the challenge. The 4 dogs receiving normal egg yolk (control group) demonstrated mild symptoms typical of CPV-2 infection, such as vomiting, diarrhea, and weight loss. No symptoms were observed by 16 d after challenge in the 3 dogs receiving 2 g of IgY powder. Of the 3 dogs receiving 0.5 g of IgY powder, 2 had clinical CPV-2 disease; however, the manifestations were less severe than in the control group. Furthermore, the IgY-treated groups had significantly greater weight gain and shorter duration of virus shedding than the control group. These results indicate that IgY is useful in protecting dogs from CPV-2-induced clinical disease.     

Estimation of the carcass composition from a cross-section of the rib-loin from crossbred Japanese Black × Limousin F2 cattle by computer image analysis

The carcass composition of crossbred Japanese Black × Limousin F2 cattle was examined in order to find an accurate carcass composition equation. The test animals included 17 steers and 17 heifers. The 28 image measurements from the area encircling the vertical line to the thoracic vertebra and the line from the thoracic vertebra between the sixth and seventh rib‐bones were measured by computer image analysis. The relationships between the 29 parameters that added the carcass left side weight of the animal and the carcass composition were suggested. The carcass composition included muscle weight, muscle ratio, fat weight and fat ratio. The carcass composition from steers was estimated by an equation composed of these three or four parameters (R² = 90.80%, 79.30%, 90.75% and 73.70%, respectively). The selected parameters were measured without cutting the thoracic vertebra. The carcass composition from heifers was estimated by an equation composed of two to four parameters (R² = 96.15%, 90.98%, 93.60% and 88.22%, respectively). The parameters for the estimation of the muscle and fat weight, and muscle and fat ratio are very similar. Furthermore, the equations using the parameters could estimate the carcass composition from the Japanese Black × Limousin cattle resource population.     

Caprine somatic cell nuclear transfer using in vivo matured oocytes collected by laparoscopic follicular aspiration

In vivo matured oocytes collected by laparoscopic follicular aspiration (LFA) from hormone treated female goats were used as recipient ooplasts for somatic cell nuclear transfer (SCNT). Japanese native (Shiba) goats were used as donor females and some donor females were used repeatedly (two or three times) at intervals of a few months. To induce synchronization of estrus, a sponge containing 0.5 g of progesterone was inserted into the vagina of each goat for 14 days. These animals were also treated with follicle stimulating hormone (FSH) in a series of 8 injections over 4 days. The first FSH injection was administered on the morning of day 9 of sponge insertion. On the morning of day 13, 50 µg of gonadotropin‐releasing hormone (GnRH) was injected into each animal. Twenty‐nine hours after GnRH injection, LFA was performed. After removal of cumulus cells, collected oocytes with the first polar body were selected and enucleated for nuclear transfer. Anterior pituitary cells isolated from an adult male Shiba goat were transfected with a DNA fragment containing the enhanced green flourescent protein gene and the puromycin resistance gene. A single donor cell was inserted into the perivitelline space of each enucleated oocyte and fusion was induced with one electric pulse of 20 V for 10 µs. The SCNT goat eggs were cultured in chemically defined medium at 38.5°C in 5% CO₂, 5% O₂, 90% N₂ for 9 days. By LFA, 396 oocytes were collected from a total of 30 females. After removal of cumulus cells, 64% of them extruded the first polar body. The percentage of SCNT goat eggs produced using in vivo matured oocytes which developed to the blastocyst stage (20–21%) was significantly higher (P < 0.05) than that produced with in vitro matured oocytes (3–8%).