Nitrogen fertilization affects yields and storage compound contents in seeds of field-grown soybeans cv Enrei (Glycine max. L) and its super-nodulating mutant En-b0-1 through changing N2 fixation activity of the plants

ABSTRACT

We compared the protein and oil contents, seed yields, and natural abundance of ¹⁵N (σ¹⁵N) of seeds from the plants of the cultivar Enrei, which has moderate nodulating ability (Enrei) with those of its two near-isogenic lines (NILs), a super-nodulating genotype of Enrei, i.e., En-b0-1, and a non-nodulating genotype of Enrei, i.e., En1282. Plants of these three genotypes were grown on four types of field plots with different types of urea coated slow-release nitrogen (N) fertilizers (CUSLNFs) which delivered N in different manners during plant growth . The seed yield of the En1282 plants was similar to that of the Enrei plants but much greater than that of the En-b0-1 plants when the plants were grown on the field to which a CUSLNF with a long lifespan was applied. The amounts of protein per seed were positively correlated with those of oil per seed in the case of En1282 plants irrespective of the field N conditions. The seed protein contents were proportional to the seed weight in both En1282 and Enrei plants. Such a relationship was not observed in the En-b0-1 plants, and the protein and oil contents in the seeds of En-b0-1 plants were negatively correlated with each other. These observations suggested that the N supply to maturing seeds was a key to the protein contents in the En1282 and Enrei plants and that the C supply to maturing seeds was a key to the protein contents in the En-b0-1 plants. The comparison of the σ¹⁵N values, protein contents, and seed yields of seeds from En1282 plants suggested that the Enrei plants assimilated considerable amounts of N from the soil during the late plant growth. We concluded that high N₂ fixation activity depressed the amounts of oil per seed and changed the protein and oil contents in soybean seeds.     

Cardiovascular effects of medetomidine, detomidine and xylazine in horses

The cardiovascular effects of medetomidine, detomidine, and xylazine in horses were studied. Fifteen horses, whose right carotid arteries had previously been surgically raised to a subcutaneous position during general anesthesia were used. Five horses each were given the following 8 treatments: an intravenous injection of 4 doses of medetomidine (3, 5, 7.5, and 10 microg/kg), 3 doses of detomidine (10, 20, and 40 microg/kg), and one dose of xylazine (1 mg/kg). Heart rate decreased, but not statistically significant. Atrio-ventricular block was observed following all treatments and prolonged with detomidine. Cardiac index (CI) and stroke volume (SV) were decreased with all treatments. The CI decreased to about 50% of baseline values for 5 min after 7.5 and 10 microg/kg medetomidine and 1 mg/kg xylazine, for 20 min after 20 microg/kg detomidine, and for 50 min after 40 microg/kg detomidine. All treatments produced an initial hypertension within 2 min of drug administration followed by a significant decrease in arterial blood pressure (ABP) in horses administered 3 to 7.5 microg/kg medetomidine and 1 mg/kg xylazine. Hypertension was significantly prolonged in 20 and 40 microg/kg detomidine. The hypotensive phase was not observed in 10 microg/kg medetomidine or detomidine. The changes in ABP were associated with an increase in peripheral vascular resistance. Respiratory rate was decreased for 40 to 120 min in 5, 7.5, and 10 microg/kg medetomidine and detomidine. The partial pressure of arterial oxygen decreased significantly in 10 microg/kg medetomidine and detomidine, while the partial pressure of arterial carbon dioxide did not change significantly. Medetomidine induced dose-dependent cardiovascular depression similar to detomidine. The cardiovascular effects of medetomidine and xylazine were not as prolonged as that of detomidine. KEY WORDS: cardiovascular effect, detomidine, equine, medetomidine, xylazine.     

The sex determining gene of medaka: a Y-specific DM domain gene (DMY) is required for male development

Although the sex-determining gene Sry has been identified in mammals, no comparable genes have been found in non-mammalian vertebrates. To clone positionally the sex-determining region of the medaka, Oryzias latipes, we generated a Y congenic strain to highlight the genetic differences between the X and Y chromosomes from inbred strains of medaka. We used recombinant breakpoint analysis and deletion analysis of the Y chromosome of a congenic XY female to restrict the sex-determining region to 250-kb stretch of the Y chromosome. Shotgun sequencing of this region predicted 27 genes. Three of these genes were expressed during sexual differentiation. However, only one gene was Y specific. The full-length cDNA sequence of this gene encodes a putative protein of 267 amino acids, including the highly conserved DM domain. We thus named it DMY. To establish a role for DMY during sexual differentiation, we screened wild medaka populations for naturally occurring DMY mutants. Two XY females with distinct mutations in DMY were found in separate populations. The first heritable mutant – a single insertion in exon 3 and the subsequent truncation of DMY – resulted in all XY female offspring. Similarly, the second XY mutant female showed reduced DMY expression with a high proportion of XY female offspring. Furthermore, during normal development, DMY is expressed only in somatic cells of XY gonads. These findings strongly suggest that the sex-specific DMY is required for normal testicular development and is a prime candidate for the medaka sex-determining gene.     

Influence of zinc deficiency to the mice infected with Babesia microti

Zinc (Zn) is an essential trace element for DNA synthesis and for cell growth and differentiation. The deficiency induces a wide range of disorders including immunodeficiency. In this study, the influence of Zn deficiency to the mice infected with Babesia microti was examined, and was compared with the influence in the rats infected with B. rodhaini previously reported. Experiments of B. microti infection were conducted using Zn-deficient (ZD; allowed to eat ad libitum on the ZD diet), Zn-adequate (ZA; allowed to eat ad libitum on the ZA diet), and diet-restricted (DR; supplied 2 g/day on the ZA diet) mice. It was suggested that the Zn deficiency exacerbated the infection dynamics of the mice with B. microti by the growth retardation, the reduction of immunity and the decrease in PCV. The results in the mice supported the consequences in the rats previously reported.     

Shoot control of nodulation is modified by the root in the supernodulating soybean mutant En6500 and its wild-type parent cultivar Enrei

Abstract

Based on grafting studies, both supernodulating (Carroll et al. 1985a, b) and hypernodulating (Gremaud and Harper 1989) soybean ([itGlycine max} L. Merr.) phenotypes were reported to be under the control of shoot factors (Delves et al. 1986, 1987; Cho and Harper 1991). Recently Akao and Kouchi (1992) have isolated a new supernodulating mutant (En6500) from ethyl methane sulfonate (EMS)-treated Enrei, a cultivar which is widely grown in the central districts of Japan. This mutant has been shown to produce several fold as many nodules as its wild-type parent cultivar when grown at a low concentration (0.5 mol m^-3) of nitrate. Moreover, it exhibited a continuous increase in the nodule number with the increasing nitrate concentration, even at 15 mol m^-3 (Francisco et al. 1992), in contrast to the similar mutant nts382 in which the nodulation decreased even at the relatively low nitrate level of 5.5 mol m^-3 (Carroll et al. 1985a). In this study we conducted grafting experiments to determine which plant part controls the supernodulation of En6500.     

Isolation and characterization of eight microsatellite loci in the Otton frog, Babina subaspera

The Otton frog, Babina subaspera, is an endangered forest frog species with unusual morphological and ecological features compared with other frogs. Eight microsatellite markers were isolated from B. subaspera and characterized with 24 individuals from Amami Islands, Kagoshima prefecture, Japan. The number of alleles observed for each locus ranged from 9 to 19 (average 13.9). The observed heterozygosity (H _O) and the expected heterozygosity (H _E) ranged from 0.71 to 0.92 and 0.83 to 0.92, respectively. These microsatellites will be useful for future genetic studies of B. subaspera, which will be essential in the conservation of this species.     

Ready chemical conversion of acid hydrolysis lignin into water-soluble lignosulfonate III: Successive treatment of acid hydrolysis lignin and a lignin model compound by phenolation and arylsulfonation*

The chemical conversion of red pine sulfuric acid lignin (Klason lignin) (SAL) as an acid hydrolysis lignin sample to water-soluble arylsulfonates of lignin derivation (i.e., phenolized SAL) was investigated. Treatment of phenolized SAL with chlorosulfonic acid followed by alkali hydrolysis gave water-soluble sulfonated products with a sulfonic acid group on their aromatic nuclei quantitatively. The products possess 2.0 SO₃Na/C₉ C₆. In contrast, the content of sulfuric acid group in sulfonated SAL was only 0.33C₉. Chlorosulfonation of 1-guaiacyl-l-p-hydroxyphenylethane as a phenolized guaiacyl lignin model compound revealed that the sulfonyl chloride group was introduced at thepara position of an aromatic methoxyl group, theortho position of a phenolic hydroxyl group, or both.     

Spatial variation of quantitative color traits in green and black types of sea cucumber <Emphasis Type="Italic">Apostichopus japonicus</Emphasis> (Stichopodidae) using image processing

It has been suggested that the Japanese sea cucumber, Apostichopus japonicus, has three color types (red, green, and black), although the qualitative difference between the color types, particularly between the green and black types, is unclear because of continuous color variation among color types. This study elucidated the color variation between green and black types using image processing (RGB, red–green–blue system) and multivariate analysis to demonstrate whether or not the black and green types can be quantitatively classified. Moreover, spatial variation of the RGB value among various local sites was clarified to estimate potential environmental factors that may affect the color variation. The series of analyses revealed that a quantitative boundary between green and black types could be provisionally established, and also that spatial variability in the intermediate (continuous) color trait between green and black types was significant. Potential environmental factors (depth and industrial activity index) were correlated with the color traits in both color types. These results suggest that the green and black types cannot be regarded as independent color traits and that the color variation between green and black types may be influenced by local environmental factors.     

Seagrass habitat reduces vulnerability of red sea bream <Emphasis Type="Italic">Pagrus major</Emphasis> juveniles to piscivorous fish predator

ABSTRACT:   Predation experiments were conducted in mesocosms to test the hypothesis that habitat complexity affects vulnerability of red sea bream Pagrus major juveniles to piscivorous fish predators. Juvenile behavior was video-recorded for 6 h in two structurally different habitats: vegetated with sea grass Zostera marina , and unvegetated 0.5-t tanks. Association behavior with seagrass was observed in the vegetated tank throughout the trials. Predation experiments were conducted with 30 red sea bream juveniles (29.9 mm body length) exposed to two individuals of the piscivorous fish predator Chinese sea bass Lateolabrax sp. (261.6 mm), for 6 h in 1.0-t tanks. Predation rate (no. of fish predated on per predator per h) was significantly lower in the vegetated tank (0.02/predator per h) than in the unvegetated tank (0.27/predator per h). Present experiments indicate that habitat complexity reduces vulnerability of juvenile red sea bream to predation by piscivorous fish by serving as physical and/or visual barriers and limiting the predator's ability to pursue and capture prey. Seagrass beds in the shallow coastal waters around Japan are suggested to be an important nursery for red sea bream since they provide the juveniles with habitat complexity as well as serve as a feeding ground.     

Identification of juvenile abalone <Emphasis Type="Italic">Haliotis diversicolor</Emphasis> based on number of open and sealed respiratory pores

ABSTRACT:   Changes in the number of respiratory pores (open pores) and their imprints (sealed pores) in post-larvae and juveniles were observed and compared for four abalone species Haliotis diversicolor , H. discus discus , H. madaka , and H. gigantea . The first open pore was evident at a shell length (SL) of 1.5 mm in H. diversicolor , 1.9–2.0 mm SL in H. discus discus , and 2.3–2.4 mm SL in H. madaka and H. gigantea . The number of open pores in H. diversicolor gradually increased with growth, with four to five pores at 2.5–18.0 mm SL and five to six pores at 18.0–27.0 mm SL. The other three species maintained four to five open pores after they reached 3.4–4.5 mm SL. The total number of open and sealed pores (TNP) was greater in H. diversicolor than in the other species at the same SL. Juvenile H. diversicolor were identified among field-caught abalone by the difference in the relationship between SL and TNP (SL–TNP relationship) and also by the monoclonal antibody reaction method. The results of the two methods were in perfect agreement, indicating that our method using the SL–TNP relationship is reliable for the identification of H. diversicolor .