Identification and characterization of Marek's disease virus serotype 1 (MDV1) ICP22 gene product: MDV1 ICP22 transactivates the MDV1 ICP27 promoter synergistically with MDV1 ICP4

A previous report [Virus Genes 6 (1992) 365-378] has shown that the US1 gene of Marek's disease virus serotype 1 (MDV1) encodes a homologue of herpes simplex virus type 1 infected cell protein No. 22 (ICP22). In the present study, we expressed and identified a product of the MDV1 US1 gene in chicken embryo fibroblasts (CEFs) with the aid of a recombinant baculovirus expressing a Flag epitope-tagged MDV1 US1 gene, under control of the SRalpha promoter (composed of the enhancer region of the simian virus 40 early promoter and the R region of the human T-cell leukaemia virus type 1 long terminal repeat). In CEF infected with the recombinant baculovirus, MDV1 ICP22 was specifically and efficiently expressed in the presence of n-butyric acid. The apparent M(r) of the expressed protein was 30,000. Reporter gene assays revealed that MDV1 ICP22 by itself transactivated an MDV1 ICP27 promoter/reporter construct weakly but specifically, and furthermore, worked synergistically with MDV1 ICP4 to efficiently up-regulate the MDV1 ICP27 promoter. MDV1 ICP22 may be a regulatory protein that stimulates viral promoters in co-operation with other viral regulatory proteins such as MDV1 ICP4.     

The dynamic expression of extracellular matrix in the bovine endometrium at implantation

Remodeling of uterine endometrial extracellular matrix (ECM) is pivotal to successful implantation and placentation, and has been well described in the rodents and humans. However, bovine endometrial ECM remodeling is still vaguely defined, especially at the time of implantation. Therefore, this study investigated the distribution of four ECMs namely, types I and IV collagen, laminin and fibronectin, from days 0 to 30 of gestation in bovine endometrium by immunofluorescence microscopy. A change in the distribution pattern of ECMs was evident by day 14 of gestation as features at this stage were clearly different from those of day 14 of the estrous cycle. The immunoreactivity of type I collagen, fibronectin and laminin decreased from day 14 of gestation and was obscured by day 24 of gestation. The type I collagen fibers formed were of thinner consistency than those of the estrous cycle and showed a coarser meshwork within the epithelium sites during the implantation period. In addition, the type IV collagen and laminin immunoreactivities of epithelial basement membrane also remarkably declined at exactly the same time. By day 30 of gestation, the four ECMs had regenerated with the formation of the placentome. In conclusion, this study reveals that remodeling of ECM is essential for the successful establishment of pregnancy in the bovine.     

The inhibitory effect of a combination of imidacloprid and permethrin on blood feeding by mosquitoes in dogs raised under outdoor conditions

Combinations of imidacloprid and permethrin were frequently used to control harmful arthropod of companion animals. The inhibitory effects on blood-feeding activity of mosquitoes in dogs raised under outdoor conditions were evaluated by using combination of 10% (w/v) of imidacloprid and 50% (w/v) of permethrin as spot-on form. Dogs in the treated group received the combination imidacloprid/permethrin spot-on. After treatment, dogs in the control and treated groups were kept separately from the evening (17:00) to the morning of the following day (09:00) in two different kennels installed outdoors to mimic realistic dog-raising conditions. Mosquitoes in the kennels were collected by light traps placed in the kennels and a sweep net to determine evidence of blood feeding, and for species identification. Mosquitoes were collected at Days 5, 3 and 1 before agent treatment, and the Day of treatment, and Days 3, 7, 14, 21, 28, 35 and 42 after treatment. The percentages of blood-fed mosquitoes measured at Days 0, 3, 21, 28 and 42 after treatment were statistically significantly lower (p<0.01) in the treated group than in the control group. The most commonly collected mosquito, Culex tritaeniorhynchus, revealed statistically significant lower percentages (p<0.01) of blood-fed mosquitoes in the treated group than in the control group at the Day of treatment, and Days 3, 7, 21, 28 and 42 after treatment. It appeared that the test agent was effective in inhibiting blood feeding by adult female mosquitoes, and the efficacy lasts for 42 days after treatment under outdoor conditions.     

Cushing's disease complicated with thrombosis in a dog

Thrombosis is a potential complication of hyperadrenocorticism (HAC) in dogs. An 8-year-old male Beagle diagnosed with pituitary-dependent HAC had complicated with thrombosis in the caudal vena cava and abdominal aorta, which was treated by hypophysectomy and antithrombotic therapy. After hypophysectomy, hypercortisolemia disappeared and the general condition was also significantly improved. Ultrasonography after hypophysectomy revealed that the thrombus remained in the abdominal aorta, but the thrombus in the caudal vena cava had disappeared. However 692 days after the hypophysectomy, the dog had an acute onset of dyspnea and died. Postmortem examination revealed the presence of thrombi in the abdominal aorta and the pulmonary artery. Observations from this case show that HAC dogs must be attention to thrombosis.     

Effects of a beta‐adrenergic agonist clenbuterol) on performance,carcase composition,hepatic microsomal mixed function oxidase and antibody production in female broilers treated with or without corticosterone

1. Beta‐adrenergic agonist (Clenbuterol, 0.33 mg/kg) and corticosterone (10 mg/kg) were incorporated into a diet based on maize and soyabean meal. Their effects on performance, carcase composition, hepatic microsomal mixed function oxidase and antibody production were investigated in female broilers.

2. Dietary corticosterone reduced the titre to sheep red blood cells, while it was unchanged by clenbuterol.

3. Clenbuterol exerted a promoting effect on gain‐to‐food ratio, carcase protein and hepatic microsomal cytochrome P‐450 content.

4. Addition of clenbuterol to the corticosterone‐containing diet prevented the increase in abdominal fat weight and uric acid excretion induced by corticosterone, but did not affect total fat mass.

5. The results showed that clenbuterol reduced abdominal rather than carcase fat and prevented protein degradation in the body when chicks were treated with corticosterone. Clenbuterol also influenced the content of cytochrome P‐450, but not the humoral immunity.     

Hydrotropism in pea roots in a porous-tube water delivery system

Orientation of root growth on earth and under microgravity conditions can possibly be controlled by hydrotropism--growth toward a moisture source in the absence of or reduced gravitropism. A porous-tube water delivery system being used for plant growth studies is appropriate for testing this hypothesis since roots can be grown aeroponically in this system. When the roots of the agravitropic mutant pea ageotropum (Pisum sativum L.) were placed vertically in air of 91% relative humidity and 2 to 3 mm from the water-saturated porous tube placed horizontally, the roots responded hydrotropically and grew in a continuous arch along the circular surface of the tube. By contrast, normal gravitropic roots of Alaska' pea initially showed a slight transient curvature toward the tube and then resumed vertical downward growth due to gravitropism. Thus, in microgravity, normal gravitropic roots could respond to a moisture gradient as strongly as the agravitropic roots used in this study. Hydrotropism should be considered a significant factor responsible for orientation of root growth in microgravity.     

Reversal of ethionine intoxication in the domestic fowl with methionine and adenine sulphate

1. When DL‐methionine was administered to young chickens fed on a diet containing DL‐ethionine (2 g/kg) growth recommenced and proceeded linearly for the first 2 d; the rate was dependent on the amount of methio‐nine administered.

2. Adenine sulphate did not stimulate growth but when given with methionine the response was enhanced.     

Significance of CCN2 expression in bovine preimplantation development

In mammalian preimplantation development, the first cell lineage segregation occurs during the blastocyst stage, when the inner cell mass and trophectoderm (TE) differentiate. Species‐specific analyses are essential to elucidate the molecular mechanisms that underlie this process, since they differ between various species. We previously showed that the reciprocal regulation of CCN2 and TEAD4 is required for proper TE differentiation in bovine blastocysts; however, the function of CCN2 during early embryogenesis has remained otherwise elusive. The present study assessed the spatiotemporal expression dynamics of CCN2 in bovine embryos, and evaluated how changes to CCN2 expression (using a CCN2 knockdown (KD) blastocyst model) regulate the expression of pluripotency‐related genes such as OCT4 and NANOG. The conducted quantitative PCR analysis revealed that CCN2 mRNA was expressed in bovine oocytes (at the metaphase stage of their second meiosis) and embryos. Similarly, immunostaining detected both cytoplasmic and nuclear CCN2 at all analyzed oocyte and embryonic stages. Finally, both OCT4 and NANOG expression levels were shown to be significantly reduced in CCN2 KD blastocysts. Together, these results demonstrate that bovine CCN2 exhibits unique expression patterns during preimplantation development, and is required for the proper expression of key regulatory genes in bovine blastocysts.     

Production of lipid mediators in mastitic milk of cow

Bovine mastitis is one of the most prevalent and costly diseases in the dairy industry. Lipid mediators are signaling molecules which coordinately and intricately modulate inflammation. They are produced from polyunsaturated fatty acids (PUFAs) in the cellular membrane via several enzymes including cyclooxygenase (COX) and lipoxygenase (LOX). In the present study, we performed comprehensive analysis of lipid production in milk obtained from clinical or subclinical mastitic cows using liquid chromatography/mass spectrometry. We detected 26, 24, and 40 kinds of lipid constantly in healthy, subclinical, and clinical mastitic milk, respectively. In clinical mastitic milk, the amount of a major n‐6 PUFA, arachidonic acid (AA), tended to increase, whereas amounts of major n‐3 PUFAs, eicosapentaenoic acid and docosahexaenoic acid, tended to decrease. The amounts of several AA‐derived lipids including COX‐catalyzed prostaglandin (PG) D₂ and PGE₂, and LOX‐catalyzed leukotriene (LT) B₄ were increased in clinical mastitic milk. Although subclinical mastitic milk represented similar trend of lipid production to healthy milk, amounts of several lipids such as LTD₄, 14,15‐dihydroxyeicosatrienoic acid, and 14‐epoxyeicosatrienoic acid changed. These findings would be helpful for better understanding of mastitis pathology and give us some insights to develop a new diagnostic and therapeutic strategy.     

Comparative observation on the growth changes of the histochemical properties and collagen architecture of the Musculus puboischiofemoralis pars medialis from Silky, layer-type and meat-type cockerels

Growth‐related changes in the histochemical properties and collagen architecture of the Musculus puboischiofemoralis pars medialis were compared among Silky, layer‐type, and meat‐type cockerels. Histochemical and immunohistochemical methods were employed and collagen architecture was studied using scanning electron microscopy. Total intramuscular collagen was also determined. The myofibers were categorized as type I, type IIA and a transitional form, type I‐tr. The proportion of type I‐tr myofibers diminished and these myofibers were transformed entirely into type I myofibers in meat‐type but incompletely in the others. The largest diameter of type I myofiber was found in layer‐type at 30 weeks of age. At 30 weeks of age, layer‐type birds had attained well‐developed perimysial collagen bundles while meat‐type birds had less developed bundles. The endomysial collagen network had a large mesh size at 1 week and then accumulated many collagen fibrils to form a felt‐like fabric of fibrils by 30 weeks of age. Silky birds developed the thickest endomysial collagen plates of all the breeds. From these results it appears that growth‐related changes in the histological structure of M. puboischiofemoralis pars medialis are not necessarily causally affected by the different growth rates of chicken breeds.