Effect of intraluteal injection of endothelin type A receptor antagonist on PGF2alpha-induced luteolysis in the cow

Endothelin-1 (ET-1) is a luteolytic mediator in the bovine corpus luteum (CL), and its action appears to be via endothelin type A receptor (ETR-A). Thus, the aim of the present study was to determine the effect of ETR-A antagonist on PGF2alpha-induced luteolysis in the cow. Cows on days 10-12 of the estrous cycle were subjected to five intraluteal injections of the ETR-A antagonist LU 135252 in saline or only saline at -0.5, 2, 4, 6, and 8 h after PGF2alpha administration (=0 h). Serial luteal biopsies were conducted to determine the expression of mRNA in the luteal tissue. There were no significant differences in the decrease in plasma progesterone (P) concentrations and the mRNA expressions of steroidogenic acute regulatory protein and 3beta-hydroxysteroid dehydrogenase/Delta5, Delta4-isomerase between the ETR-A antagonist-treated group and the control group. However, the start of the decline in CL volume and blood flow area surrounding the CL was delayed for almost two days in the ETR-A antagonist-treated group compared to the control group. The mRNA expression of preproET-1 and endothelin type B receptor increased in both groups, while the ETR-A mRNA remained unchanged. In addition, caspase-3 mRNA expression increased significantly at 24 h in the control group only and its level was higher than that of the ETR-A antagonist-treated group. Thus, the present study suggests that ET-1 regulates structural luteolysis via ETR-A by controlling blood vessel contraction in the CL of the cow.     

Construction of a linkage map for watermelon (Citrullus lanatus (Thunb.) Matsum & Nakai) using random amplified polymorphic DNA (RAPD)

Summary A linkage map for watermelon (Citrullus lanatus) was constructed on the basis of RADP, ribosomal DNA restriction fragment length polymorphism (RFLP), isozyme, and morphological markers using F₁BC1. A segregating population of 78 individuals was the result of a backcross of a cultivated inbred line (H-7; Citrullus lanatus; 2n=22) and a wild form (SA-1; C. lanatus; 2n=22), in which the latter was the recurrent (male) parent. A total of 69 RAPD, one RFLP, one isozyme, and three morphological markers was found to segregate in the BC1 population. Linkage analysis revealed that 62 loci could be mapped to 11 linkage groups that extended more than 524 centimorgans (cM), while 12 loci segregated independently of all other markers. The locus for exocarp color was linked to two RAPD markers within a region of 5 cM on linkage group 4. The locus for flesh color was linked to a RAPD marker within a region of 30 cM on linkage group 6. The isozyme marker GOT was located on the linkage group 1. Linkage group 2 contained a locus for ribosomal DNA within 5 cM of a RAPD marker. Half of the RAPD markers on the linkage group 7 displayed severely distorted segregation. The construction of linkage map using molecular markers is necessary for the breeding of watermelon to introduce useful gene of wild watermelon efficiently. However the linkage map that was constructed for the most part on the basis of RAPD markers could not cover significant parts of the genome, the linkage map provides breeders of watermelons the possibility of tagging useful agronomic traits, as well as the gene for exocarp color.Abbreviations RAPD random amplified polymorphic DNA - RFLP restriction fragment length polymorphism - GOT glutamate oxaloacetate transaminase - MDH malate dehydrogenase - ACP acid phosphatase - 6PGH 6-phosphogluconate dehydrogenase     

Bolting resistant breeding of Chinese cabbage. 1. Flower induction of late bolting variety without chilling treatment

Summary When a local slow bolting variety Osaka Shirona Bansei (Brassica rapa L. ssp. pekinensis, syn. B. campestris L. ssp. pekinensis) was grown in a phytotron (25°C, 16 hours day length without chilling treatment), one third of the plants bolted and flowered. In order to clarify the different flowering responses in the variety, a progeny line (FNC) of the flowering plants was chilled for 4 different periods (0, 22, 36 and 53 days) in a chamber of 2 7°C, then transplanted to three different conditions, i.e. PHY: 25–20°C day and night temperatures, 16 hours day length, GHL: 10 25°C, 16 hours day length with supplementary light and GHN: 10 25°C, natural day length (10 15 hours). In PHY, FNC bolted and flowered with almost the same leaf numbers in all 4 different chilling treatments. This means that FNC has very low sensitivity and no requirement to low temperature for its reproductive growth. In GHN (short day length), FNC bolted very slowly. Then the bolting and flowering of FNC were promoted by both long day length and high temperature. The newly found bolting characteristics of Osaka Shirona Bansei could be applied to breed unique slow bolting Chinese cabbage (B. rapa L. ssp. pekinensis) which might be non-sensitive to low temperature and its bolting and flowering would be induced with the combination of long day length and high temperature. Using the unique variety, it might be also possible to establish a new cropping type of Chinese cabbage (late autumn sowing, spring harvest).Abbreviations PHY Phytotron, long day and high temperature condition - GHL Greenhouse, long day and medium temperature condition - GHN Greenhouse, natural (short) day and medium temperature condition - FNC A progeny line of Osaka Shirona Bansei which flowered with no chilling treatment - FC A progeny line of Osaka Shirona Bansei which flowered with chilling treatment     

Soil microbial biomass, dehydrogenase activity, bacterial community structure in response to long-term fertilizer management

This study describes the effects of balanced versus nutrient-deficiency fertilization on soil microbial biomass, activity, and bacterial community structure in a long-term (16 years) field experiment. Long-term fertilization greatly increased soil microbial biomass C and dehydrogenase activity, except that the P-deficiency fertilization had no significant effect. Organic manure had a significantly greater (P<0.05) impact on the biomass C and the activity, compared with mineral fertilizers. Microbial metabolic activity (dehydrogenase activity per microbial biomass C) was significantly higher (P<0.05) under balanced fertilization than under nutrient-deficiency fertilization. General bacterial community structure was analyzed by PCR-denaturing gradient gel electrophoresis (DGGE) targeting eubacterial 16S rRNA gene. Mineral fertilization did not affect the DGGE banding pattern, while specific DGGE band was observed in organic manure-fertilized soils. Phylogenetic analysis showed that the change of bacterial community in organic manure-fertilized soil might not be because of the direct influence of the bacteria in the compost, but because of the promoting effect of the compost on the growth of an indigenous Bacillus sp. in the soil. We emphasize the importance of balanced-fertilization, as well as the role of P, in maintaining soil organic matter, and promoting the biomass and activity of microorganisms.     

Characteristics of chemical components in genetic resources of garlic Allium sativum collected from all over the world

The aim of this work was to evaluate garlic diversity based on the production of chemical components in the bulbs and geographical distribution. A total of 103 garlic clones collected from worldwide sources were grown in Yamaguchi, Japan. The chemical contents–S-allyl-l-cysteine sulfoxide (AlCSO), and phenolic content—of garlic collections were determined by HPLC and Folin–Ciocalteu assay, respectively. Quantitative analysis of the chemical content showed wide variations between geographical collection sites. Morphological observation of inflorescence was performed, and clones were divided into four types according to their bolting traits: Type A—bolters, producing mainly florets; Type B—bolters, producing mainly bulbils; Type C—incomplete bolters; and Type D—non-bolters. The appearance frequencies of the bolting types varied depending on the latitude of the collection sites. A comparison of these four different types was carried out based on chemical composition data. Garlic clones that possessed florets showed a tendency for higher amount of AlCSO content than did Type B. Moreover, it was confirmed that as distance increased from high-latitude areas (Central Asia and The Northern Mediterranean), the garlic was more likely to produce bulbils in the inflorescence with lower AlCSO content and higher phenolic content. This research suggested that garlic’s transition of from sexual propagation to asexual (vegetative) propagation and changes in the chemical composition of the bulbs would have occurred in the process of expanding garlic cultivation. In conclusion, garlic seems to have obtained high environmental adaptability with these transitions and changes via artificial selection.     

Cluster analysis to evaluate disease risk in periparturient dairy cattle

Predicting periparturient disease risk is of immense value to the dairy industry. Periparturient diseases are interrelated with each other; however, predicting the onset risk of these diseases has predominantly been based on a single blood parameter for a single disease. This study examined a new diagnostic method to predict the risk of periparturient diseases. We conducted cluster analysis of multiple blood constituents from 20 Holstein cattle at 1 week post‐partum, and the cattle were divided into two groups, A or B. We then compared the periparturient and early‐lactation blood constituents of these groups. Group B had significantly higher 3‐hydroxybutyric acid concentrations and were suspected to have subclinical ketosis. Group B also had significantly lower calcium concentrations, with a tendency for subclinical hypocalcemia. We also performed discriminant analysis using blood parameters at 1 week post‐partum, which grouped the population into the same two groups as the cluster analysis based on three variables: inorganic phosphorus, calcium, and either phospholipids or total cholesterol. We further showed that these discriminant functions could be used to predict the risk of periparturient disease even before parturition. Our results indicate that cluster analysis with multiple blood constituents is useful for predicting periparturient disease risks.     

Effects of fibroblasts derived from the olfactory bulb and nasal olfactory mucosa on proliferation of olfactory ensheathing cells harvested from the olfactory bulb

Olfactory ensheathing cells (OECs) have been reported to promote axonal regeneration when transplanted to rodent spinal cord injury models. OECs are available from the olfactory bulb (OB) and olfactory mucosa (OM). Although harvesting OECs from the OM is less traumatic, OECs originating from the OM are less proliferative than those from the OB (OB-OECs). One possible reason for this difference is coexisting fibroblasts. Here, we examined the effect of coculturing either fibroblasts from the OB (OB-Fibs) or fibroblasts from the OM (OM-Fibs) on the proliferation of OB-OECs. Proliferation of OB-OECs was significantly higher in 5:5 coculture with OB-Fibs and in 7:3 and 5:5 cocultures with OM-Fibs than without fibroblasts. These results indicated that coculture with both OB-Fibs and OM-Fibs promoted the proliferation of OB-OECs.