Characterization of Mendelian and Non-Mendelian Mutant Strains by Micronuclear Transplantation in Paramecium tetraurelia

ABSTRACT. Mutant strain d48 and d12 cannot express serotype A. In d48, the A i-antigen gene is present in the micronucleus, but not in the macronucleus. It has recently been shown that d12 contains the A gene in its micronucleus, but its macronucleus lacks the gene. Micronuclear transplantations into enucleated cells were performed to analyze those mutants. Reciprocal transplantation between wild type and d48 confirmed that d48 contains the A gene in the micronucleus and its cytoplasm is defective. Wild type 51 enucleated cells into which were transplanted d12 micronuclei could not express A. Amiccronucleate d12 cells into which were transplanted normal micronuclei from 51 or d48 showed no expression of A. These results show that even if the micronucleus of d12 contains the A gene, it must be abnormal, and its cytoplasm is also defective the same as d48. Genetic analysis showed that heterozygote of d12 and wild type 51 or d48 caused a cure of the cytoplasmic defect of d48 and d12 during the development of macronuclei.     

The effect of chlorophyll content on changes of photochemical reactions in intact kidney bean leaves

Abstract. Activation spectra of photochemical reactions were measured by a flash spectrophotometer in leaves having varying chlorophyll contents at different stages of greening. The increase of chlorophyll concentration up to 30 nmol cm^-2 elevated the rates of photochemical reactions at all wavelengths of light used, and was found to be produced by an increase in the amounts of reaction centres. Further accumulation of chlorophyll up to 40 nmol cm^-2 was associated with an increase in light-harvesting chlorophyll, an improved rate of photochemical reactions around 600 nm and at 700 nm, and self-absorption and screening effects where chlorophyll absorbed maximally (400–450 nm and around 680 nm).     

Fourteen polymorphic microsatellite loci in the field gudgeon,Gnathopogon elongatus elongatus

We isolated and characterized 14 polymorphic microsatellite loci for the field gudgeon, Gnathopogon elongatus elongatus, a popular freshwater species in streams including agricultural canals in Japan. The number of observed alleles for each locus ranged from 9 to 24, and the values of observed and expected heterozygosities ranged from 0.750 to 1.000 and from 0.832 to 0.953, respectively. These microsatellite markers will be useful for studies of population genetic structure and genetic variability of the field gudgeon.     

Isolation and characterization of polymorphic microsatellite DNA markers in the Japanese eight‐barbel loach,Lefua echigonia

We isolated and characterized 17 polymorphic microsatellite loci for the Japanese eight‐barbel loach, Lefua echigonia, an endangered freshwater species in streams including agricultural canals in Japan. The number of observed alleles for each locus ranged from two to nine, and the values of observed and expected heterozygosities ranged from 0.125 to 0.844 and from 0.148 to 0.876, respectively. All loci conformed to Hardy–Weinberg equilibrium. Genetic linkage disequilibrium analysis between all pairs of the loci showed no significant departure from the null hypothesis between any of the loci.     

Growth allocation between height and stem diameter in nonsuppressed reproducing Abies mariesii trees

To understand the growth patterns with respect to competition and leaf‐mass increase in reproducing trees, growth allocation between height and stem diameter was examined for nonsuppressed reproducing Abies mariesii trees in a subalpine forest in northern Honshu, Japan. The growth allocation was analyzed by dividing the relative growth rate of the stem volume into the relative contributions of height and stem‐diameter growth. During a 9‐yr period, height growth and seed‐cone production showed obvious annual variation, while stem‐diameter growth recorded moderate variation. For two of three years of seed‐cone production during the 9‐yr period, trees with larger seed‐cone production were associated with less height growth in the following year of seed‐cone production; however, there was no trend of height growth in the year of seed‐cone production. In the following year of mast seeding, trees with larger stem‐volume growth were associated with less height growth. This trend was also shown for the relationship between the cumulative stem‐volume growth during the 9‐yr period and growth allocation to height, suggesting that trees with a larger biomass increase depress the allocation of photosynthate to competition with a large expenditure for reproduction. In contrast to this, trees with a smaller biomass increase might allocate photosynthate to competition with surrounding trees. The results of this study suggest that an increase in reproductive organs during life history and annual variation in reproduction are closely associated with the growth patterns of the stem in A. mariesii trees.     

Location of sugars in barley seeds during germination by NMR microscopy

The distribution and fluctuation of sugars in germinating barley seeds were examined by ¹³C nuclear magnetic resonance (NMR) spectroscopy, ¹H-NMR imaging and ¹H-NMR localized spectroscopy in relation to morphology. Maltose, sucrose, fructose and oils were detected in intact imbibed seeds by ¹³C-NMR spectra. During the first 6 d of germination, the maltose content increased and the oil content gradually decreased, whilst the levels of sucrose and fructose remained constant. Sugars were located by ¹H-NMR images and ¹H-NMR localized spectra in the vascular bundle of the seeds as well as in the solubilized endosperm. They were also detected in the shoots. The sugars detected in an 80% ethanol shoot extract were sucrose and glucose, which were located in the vascular bundles but not in the mesophyll cells of the coleoptile. They were also located in the basal part of the shoot, but not above 7 mm from the scutellum. The data suggest that the sugars are primarily transported through the vascular bundles and, at the same time, rapidly incorporated into mesophyll cells in the leaves.     

Isolation and characterization of polymorphic microsatellite DNA markers in the Omono type of ninespine stickleback,genus Pungitius

We isolated and characterized 25 polymorphic microsatellite loci for the Omono type of ninespine stickleback, genus Pungitius, an endangered species in streams including agricultural canals in Japan. The number of observed alleles per locus ranged from two to 15 within 32 individuals each collected from three populations in the Omono River, and the values of observed and expected heterozygosities ranged from 0.031 to 0.906 and from 0.031 to 0.856, respectively. All loci conformed to the Hardy–Weinberg equilibrium. Genetic linkage disequilibrium analysis between all pairs of the loci showed no significant departure from the null hypothesis between any of the loci.