Growth of Glucose-uptake-deficient Mutant of Xanthomonas oryzae pv. oryzae in Rice Leaves

We isolated Xanthomonas oryzae pv. oryzae mutants deficient in the phosphoenolpyruvate : carbohydrate phos-photransferase system, a major glucose transport system in bacteria, using the glucose analogue 3-deoxy-3-fluoro-d-glucose (3FG). Glucose uptake by the mutants was decreased to 15–35% of the parental strain, and growth greatly decreased in synthetic media containing glucose as a sole sugar source. Growth of the mutants in rice leaves was, however, similar to the wild type. These findings suggest that glucose is not necessarily a major carbohydrate source for X. o. pv. oryzae in rice leaves. Received 11 August 2000/ Accepted in revised form 15 December 2000     

Change in intrarenal Ghrelin expression in immune complex-mediated glomerular disease in dogs

Ghrelin is a peptide hormone that is mainly produced by the stomach. The kidney is a major source of local ghrelin, and maintaining body fluid balance is considered a critical role of renal ghrelin. However, there are no reports on renal ghrelin in small animal medicine. The present study investigated the intrarenal localization of and change in ghrelin expression in dogs with immune complex-mediated glomerulonephritis (ICGN). Ghrelin immunoreactivity (IR) was observed in the distal tubules of normal kidneys. Ghrelin IR was weak in ICGN kidneys, and the quantitative ghrelin IR score was significantly lower in ICGN kidneys than in normal kidneys. In cases of ICGN, plasma creatinine concentrations showed a positive correlation with the ghrelin IR score.     

Genetic evaluation of the longevity of the Holstein population in Japan using a Weibull proportional hazard model

The objective of this study was to confirm the stability of the genetic estimation of longevity of the Holstein population in Japan. Data on the first 10 lactation periods were obtained from the Livestock Improvement Association of Japan. Longevity was defined as the number of days from first calving until culling or censoring. DATA1 and DATA2 included the survival records for the periods 1991–2003 and 1991–2005, respectively. The proportional hazard model included the effects of the region-parity-lactation stage-milk yield class, age at first calving, the herd–year–season, and sire. The heritabilities on an original scale of DATA1 and DATA2 were 0.119 and 0.123, respectively. The estimated transmitting abilities (ETAs) of young sires in DATA1 may have been underestimated, but coefficient δ, which indicated the bias of genetic trend between DATA1 and DATA2, was not significant. The regression coefficient of ETAs between DATA1 and DATA2 was very close to 1. The proportional hazard model could steadily estimate the ETA for longevity of the sires in Japan.     

The original papers appeared in the Journal of Japanese Forestry Society vol. 86, no. 3 in Japanese with English abstracts

Abstracts from the Journal of Japanese Forestry Society

The original papers appeared in the Journal of Japanese Forestry Society vol. 86, no. 3 in Japanese with English abstracts     

Nitrification Inhibitors from the root tissues of Brachiaria humidicola, a tropical grass

Nitrification inhibitory activity was found in root tissue extracts of Brachiaria humidicola, a tropical pasture grass. Two active inhibitory compounds were isolated by activity-guided fractionation, using recombinant Nitrosomonas europaea containing luxAB genes derived from the bioluminescent marine gram-negative bacterium Vibrio harveyi. The compounds were identified as methyl-p-coumarate and methyl ferulate, respectively. Their nitrification inhibitory properties were confirmed in chemically synthesized preparations of each. The IC50 values of chemically synthesized preparations were 19.5 and 4.4 microM, respectively. The ethyl, propyl, and butyl esters of p-coumaric and ferulic acids inhibited nitrification, whereas the free acid forms did not show inhibitory activity.     

Characterization of the reproductive cycle in female bharals (Pseudois nayaur) based on the changes in serum progesterone concentrations and parturition season

The purpose of present study was to determine annual changes in serum progesterone (P(4)) concentrations and to clarify basic reproductive characteristics, such as breeding season, estrous cycle, and puberty in female bharals (Pseudois nayaur). Blood was collected from 9 female bharals once or twice weekly for approximately one year. Serum P(4) concentrations were determined by radioimmunoassay. Serum P(4) concentrations showed remarkable and cyclic changes between November/December (winter) and May/June (late spring). The mean estrous cycle was 24.9 +/- 0.5 days. Chasing insistently to other females and discharge of mucus from the vulva were observed around the time when the serum P(4) concentrations began to increase. The chasing behavior and discharge of mucus were considered to be external indicators of estrus in female bharals. Serum P(4) concentrations of a pregnant female had non-cyclic changes, and the values remained high. In this study, all 37 deliveries were between April and September, and about 70% of these were concentrated in May and June. The conception month determined on the day of birth was between October and April for all animals, and the most common month was in December (54%). This month corresponded to an early stage of the period when the serum P(4) concentrations changed cyclically. These results indicate that many female bharals become pregnant at the beginning of the breeding seasons and, if they do not become pregnant, the estrous cycle, about 25 days in length, is repeated.     

Effects of feeding calves genetically modified corn bt11: a clinico-biochemical study

Genetically modified corn Bt11 is insect-resistant and expresses Cry1Ab toxin, an insecticidal protein, in kernels. Although Bt11 corn is considered safe based on animal performance, there are no reports available on the clinico-biochemical effects of feeding it to cattle. In this study, we evaluated the effects of feeding Bt11 to calves, using blood and ruminal clinico-biochemical parameters. Our three-month-long feeding experiment demonstrated that calves (n=6), fed with a ration containing 43.3% of Bt11 corn kernels as dry matter, did not develop any discernible clinical, hematological, biochemical, or ruminal abnormalities as compared with control calves (n=6) fed non-Bt11 corn. The results suggest that the transgenic Bt11 has no negative clinico-biochemical effects on calves.     

Fine mapping of foxglove aphid (Aulacorthum solani) resistance gene Raso1 in soybean and its effect on tolerance to Soybean dwarf virus transmitted by foxglove aphid

Soybean dwarf virus (SbDV) causes serious dwarfing, yellowing and sterility in soybean (Glycine max). The soybean cv. Adams is tolerant to SbDV infection in the field and exhibits antibiosis to foxglove aphid (Aulacorthum solani), which transmits SbDV. This antibiosis (termed “aphid resistance”) is required for tolerance to SbDV in the field in segregated progenies of Adams. A major quantitative trait locus, Raso1, is reported for foxglove aphid resistance. Our objectives were to fine map Raso1 and to reveal whether Raso1 alone is sufficient to confer both aphid resistance and SbDV tolerance. We introduced Raso1 into cv. Toyomusume by backcrossing and investigated the degree of aphid antibiosis to foxglove aphid and the degree of tolerance to SbDV in the field. All Raso1-introduced backcross lines showed aphid resistance. Interestingly, only one Raso1-introduced backcross line (TM-1386) showed tolerance to SbDV in the field. The results demonstrated Raso1 alone is sufficient to confer aphid resistance but insufficient for SbDV tolerance. Tolerance to SbDV was indicated to require additional gene(s) to Raso1. Additionally, Raso1 was mapped to a 63-kb interval on chromosome 3 of the Williams 82 sequence assembly (Glyma1). This interval includes a nucleotide-binding site–leucine-rich repeat encoding gene and two other genes in the Williams 82 soybean genome sequence.     

Agronomic traits and gene containment capability of cleistogamous rice lines with the superwoman1-cleistogamy mutation

Pollen-mediated transgene flow is a major concern for the production of genetically modified (GM) rice. Cleistogamy is a useful tool for preventing this form of gene flow. We previously identified the cleistogamous rice mutant superwoman1-cleistogamy (spw1-cls) and determined its molecular genetic mechanism. In the present study, we cultivated spw1-cls over five years to examine effects of cleistogamy on agronomic traits. Simultaneously, we cultivated cleistogamous backcross lines created by continuous backcrossing with “Yumeaoba” (a japonica cultivar) as the recurrent parent and by application of a DNA marker. In these experimental cultivations, spw1-cls and its backcross lines showed almost equal or slightly lower, but acceptable, agronomic traits compared with each control line. We also conducted natural crossing tests in paddy fields to assess the gene containment capability of spw1-cls. In a series of field experiments, there was no natural crossing between spw1-cls (pollen donor) and pollen recipient lines, but the wild-type donor and recipient lines were crossed. Thus, the cleistogamy of the spw1-cls mutation is able to inhibit natural crossing effectively, without significant loss of commercial benefits, such as yield. We conclude that spw1-cls cleistogamy is a practical tool for gene containment in GM rice cultivation.