Relationships between sap flow,hydraulic conductivity,and the anatomical characteristics of stems and roots in apple rootstocks of different vigour

Summary

To find a useful parameter that could be related to the degree of rootstock vigour, for rootstock breeding programmes, sap flow, hydraulic conductivity, and the anatomical characteristics of stems and roots were measured in 1-year-old trees of apple rootstocks of different vigour. Sap flow was less active in dwarfing rootstocks than in invigorating rootstocks, when taking leaf area into account, under a controlled temperature of 20ºC with the root zone at 15ºC. The hydraulic conductivities of stems and roots were not consistent with the degree of dwarfing.The hydraulic conductivity of the stem appeared to be related to the diameter and density of the large vessels in the xylem. On the other hand, the phloem-to-xylem ratio in roots with diameters of 1.5 – 2.0 mm, was closely-related to sap flow and the degree of dwarfing. The phloem-to-xylem ratio decreased as the degree of vigour increased. Moreover, the phloem-to-xylem ratio was considered to be related to the ability of roots to absorb and transport water, which was expressed as the root-specific sap flow. Therefore, the phloem-to-xylem ratio could be a useful index for evaluating the potential of apple trees as dwarfing rootstocks.     

Cloning of porcine interleukin (IL)-12 receptor beta2 (IL-12Rbeta2) gene and its application to a rapid biological assay for human/porcine IL-12

Porcine IL-12Rbeta2 gene was cloned from mRNA preparation of mitogen-activated peripheral blood mononuclear cells (PBMCs), and its complete nucleotide sequence was determined. To confirm the biological function, the entire open reading frame (ORF) was re-cloned into a mammalian expression vector, pcDNA3.1/Zeo(+), at the downstream of CMV promoter, and introduced to a Th1-like human lymphoma cell line, Jurkat E6-1. Antibiotic-resistant cells retaining the expression construct were selected then, isolated by the limiting dilution method. An established clone (10B10) constitutively expressed chimeric IL-12Rs composed of intrinsic (human) beta1 and extrinsic (porcine) beta2 subunits, and produced interferon (IFN)-gamma in response to IL-12 of both species with optimal PHA/PMA stimulation. The production of IFN-gamma was observed as early as 42 h after culture and appeared to be dose-dependent within the range between 20 and 2000 pg/ml. Thus, this clone not only reacts with IL-12 of both species but also provides a useful tool for quick and sensitive detection of IL-12 bioactivity.     

Expression of a testis-specific form of TBP-related factor 2 (TRF2) mRNA during mouse spermatogenesis

The gene encoding TATA-binding protein-related factor 2 (TRF2/TLF/TLP/TRP), essential for the progress of spermiogenesis, is abundantly expressed in mammalian testis. A sequence database search revealed that mouse TRF2 is encoded by two mRNAs containing the same protein-coding region and different 5'-untranslated regions. Northern blot analysis using DNA probes specific for the 5'-untranslated regions demonstrated that these two mRNAs are distinguished from each other by the expression patterns: ubiquitous and testis-specific expression. The ubiquitously expressed form of TRF2 mRNA was present at a very low level throughout testicular development, whereas expression of the testis-specific form was first detectable in the 14-day-old testis, and the mRNA level abundantly increased at the later stages of testicular development. Western blot analysis indicated that the TRF2 level increases during testicular development, which is consistent with the expression pattern of the testicular form of TRF2 mRNA. Thus, the presence of the testis-specific form of TRF2 mRNA may account for overexpression of the TRF2 gene in the testis.     

Increase of antibody titer against Leucocytozoon caulleryi by oral administration of recombinant R7 antigen

In this study, we examined oral administration with recombinant R7 (rR7) antigen expressed in Escherichia coli using chicken leucocytozoonosis subunit vaccine (LV)-vaccinated and unvaccinated chickens. Only LV-vaccinated chickens showed re-induction of anti-second-generation schizont (2GS) antibody. Also, LV-vaccinated chickens whose anti-2GS antibody titer was middle-level showed increases of the antibody titer compared to vaccinated-control chickens (P>0.01, >0.05) after oral administration with rR7 antigen.     

Generation of multinucleated giant cells in vitro from bovine monocytes and macrophages

The generation of multinucleated giant cells (MGC) from cells of the bovine monocyte-macrophage lineage was investigated. Freshly isolated monocytes were incubated with the conditioned medium (CM) of peripheral blood mononuclear cell cultures treated with Concanavalin A for 1-4 days (CM1 to CM4). Only CM1 generated MGC despite similar concentrations of IFNgamma in all CMs. Nevertheless, MGC formation from monocytes was enhanced by adding either macrophage colony-stimulating factor (M-CSF) or granulocyte-macrophage colony-stimulating factor (GM-CSF), MGC formations from macrophages were observed only when macrophages were cultured with GM-CSF plus CM. These results indicate that several mechanisms to generate MGC from bovine monocytes-macrophage lineage cells exist, and that GM-CSF is a major mediator of MGC formation in cattle.     

Interval mapping of growth quantitative trait loci in Japanese Black beef cattle using microsatellite DNA markers and half-sib regression analysis

A confirmatory scan for the regions of bovine chromosome 1 segregating the quantitative trait loci (QTL) influencing birthweight, weaning weight, yearling weight, and preweaning and postweaning average daily gains was performed by genotyping half‐sib progeny of four Japanese Black sires using microsatellite DNA markers. Data were analyzed by generating an F‐statistic every 1 cM on a linkage map by the regression of phenotype on the probabilities of inheriting an allele from the sire after adjusting for the fixed effects of sire, sex, parity and season of birth as well as age as a covariate. Permutation tests at chromosome‐wide significance thresholds were carried out over 10 000 iterations. A significant QTL for birthweight at 114 cM was detected in the sire 2 family. This identification of a birthweight QTL in Japanese Black cattle may be useful for the implementation of marker‐assisted selection.     

Effects of enalapril in cats with pressure overload-induced left ventricular hypertrophy

In order to evaluate the effect of enalapril on haemodynamics and renal function in a pressure overload model, we prepared eight feline models of left ventricular hypertrophy (LVH) by banding of the aortic arch. The LVH cats were assigned to the placebo group or the enalapril group (0.5 mg/kg, PO, sid) 3 months following surgery, and each received its respective drug for 4 weeks. Each week, blood pressure, angiotensin converting enzyme (ACE) activity in blood, and creatinine clearance were measured, and complete blood count (CBC), biochemical examination of the blood, echocardiography, and chest radiography were carried out. The interventricular septum thickness (IVSd, IVSs), fractional shortening (FS), and ejection fraction (EF) increased significantly in the LVH cats following surgery (P<0.05). There was no significant difference between the placebo group and the enalapril group with respect to general physical parameters, CBC, biochemical parameters and renal function. In the enalapril group, systolic arterial pressure, mean arterial pressure, and ACE activity in blood decreased significantly following administration (P<0.05). In addition, the left ventricular free wall thickness in diastole and IVSd decreased significantly following administration (P<0.05). These results suggest that, in a pressure overload model, enalapril (0.5 mg/kg, sid) inhibits cardiac hypertrophy, reduces blood pressure, and does not adversely affect renal function.     

Beating the standard quantum limit with four-entangled photons

Precision measurements are important across all fields of science. In particular, optical phase measurements can be used to measure distance, position, displacement, acceleration, and optical path length. Quantum entanglement enables higher precision than would otherwise be possible. We demonstrated an optical phase measurement with an entangled four-photon interference visibility greater than the threshold to beat the standard quantum limit-the limit attainable without entanglement. These results open the way for new high-precision measurement applications.     

Development of a new selection method and quality improvement of sugary-1 rice mutants

Brown rice of sugary-1 mutants has a wrinkled character because of the presence of phytoglycogen instead of starch in the inner part of the endosperm. Because the wrinkled phenotype was used as a sole selection marker for progeny of the sugary-1 strain, identification of mutant seeds with improved appearance is very difficult. We found that sugary-1 varieties contained not only phytoglycogen but also free glucose in the endosperm, and these were positively correlated. In the segregated F₂ seeds that resulted from crossing Hokurikutou237 (sugary-1) and Koshihikari strains, glucose and phytoglycogen were also significantly correlated. Thus, we identified new sugary types with improved appearance from these progeny using glucose measurements. The F₄ seeds of the improved strain had moderate phytoglycogen contents and seed germination characteristics. Native-PAGE showed that pullulanase activity in the improved strain increased in developing seeds compared with Hokurikutou237, although isoamylase activity was extremely low and similar to that in sugary-1 types. The new selection method in this study efficiently aids the development of improved sugary rice types that lack the wrinkled phenotype.