Chimeric heterosis in mandibular size in mice

Morphometrical observations were carried out on the mandibles of chimeras made from the embryos of C57BL/6 and BALB/c mice to compare with the two strains and their reciprocal F1 crosses. The results of the principal component analysis indicate that the first principal component (PC1) and the second principal component (PC2) extracted might be acceptable as size and shape factors, respectively. Variations of both PC1 and PC2 were generally larger in the chimeras than in the two component strains and their F1 crosses. The mean PC1 value of the chimeras was larger than that of the two component inbred strains, and it was similar to that of F1 crosses, or slightly larger. The overall size of the mandible represented by PC1 tended to be larger in the chimeras consisting of two component cells that were approximately equivalent than in those that shifted to either cell population. The above trend was observed in both sexes. These results indicate that chimeric heterosis due to the interaction between genetically different cells (C57BL/6 and BALB/c) has some relation to mandible size. The mean PC2 value, which was accepted as shape factor, was intermediate between the two inbred strains. The mandible size (PC1) and shape (PC2) were bilaterally symmetrical, except for the shape in the female chimeras and in (C57BL/6 x BALB/c)F1.     

Isolation and Sequencing of a Genomic Clone for Mouse Brain Specific Small RNA

We isolated a mouse genomic clone that hybridized with small RNA present in the cytoplasm of the brain. The RNA was about 150 nucleotides long. This RNA seemed to be specific to the brain, since it was not found in the liver or kidney. The clone DNA contained a sequence homologous to 82-nucleotide "identifier" core sequence of cDNA clones of rat. The sequence contained a split promoter for RNA polymerase III and was flanked by a 12-nucleotide direct repeat (ATAAATAATTTA).     

Nalidixic acid-resistant mutations of the gyrB gene of Escherichia coli

Summary DNA fragments of 3.4 kb containing the gyrB gene were cloned from Escherichia coli KL-16 and from spontaneous nalidixic acid-resistant mutants. The mutations (nal-24 and nal-31) had been determined to be in the gyrB gene by transduction analysis. Nucleotide sequence analysis of the cloned DNA fragments revealed that nal-24 was a G to A transition at the first base of the 426th codon of the gyrB gene, resulting in an amino acid change from aspartic acid to asparagine, and nal-31 was an A to G transition at the first base of the 447th codon, resulting in an amino acid change from lysine to glutamic acid. This indicates that mutations in the gyrB gene are responsible for nalidixic acid resistance.     

Preparation and characterization of two major isotypes of parvalbumins from skeletal muscle of bullfrog (Rana catesbeiana)

Two major isotypes of parvalbumins (PA1 and PA2) have been isolated from the skeletal muscle of bullfrog, Rana catesbeiana. The Mr values were estimated to be 10,100 (PA1) and 11,800 (PA2) by SDS/polyacrylamide gel electrophoresis, and the isoelectric points were determined to be 4.78 (PA1) and 4.97 (PA2) by polyacrylamide gel isoelectric focusing. The amino acid compositions and isoelectric points indicate that PA1 corresponds to Rana esculenta pI 4.50 and Rana temporaria pI 4.75 parvalbumins and PA2 to Rana esculenta pI 4.88 and Rana temporaria pI 4.97 parvalbumins, showing that PA1 is genetically a beta-parvalbumin and PA2 an alpha-parvalbumin. However, in terms of the amino acid compositions, PA1 and PA2 are distinctly different from the corresponding parvalbumins of Rana esculenta or Rana temporaria. The ultraviolet spectra of PA1 and PA2 are consistent with their amino acid compositions. An ultraviolet difference spectrum of the Ca2+-loaded form vs. metal-free form indicates that a Tyr and some Phe residues in PA1 are affected by a conformational change associated with the binding of Ca2+. On electrophoresis in polyacrylamide gel in 14 mM Tris and 90 mM glycine, the Ca2+-loaded form of PA1 migrated twice as fast as the Mg2+-loaded form. Both PA1 and PA2 show increased mobility in the Ca2+-loaded forms, like troponin C but different from calmodulin.     

Bimodal length frequency distribution in 0+aged masu salmon,Oncorhynchus masou,in a natural stream of southern Hokkaido

The frequency distribution of the fork length of 0⁺ aged masu salmon,Oncorhynchus masou, changed from unimodal to bimodal distribution in autumn of the years from 1982 to 1984 in the Mogusa River of southern Hokkaido, Japan. The bimodal distribution consists of two (upper and lower) modal groups. These two groups resulted from a difference in growth rate of 0⁺ aged individuals in autumn. Fish belonging to the upper modal group are assumed to be potential 1⁺ smolts. Whether 0⁺ aged parr transform into smolt or remain as parr in the following spring may be related to the growth rate of fish in the first autumn.     

Promotion of Rooting in Azukia Cuttings by Possible Glycoproteins Extracted from Lentinus edodes Culture

Macromolecules purified from Lentinus edodes mycelia cultureenhanced adventitious root formation in Azukia epicotyl cuttings.Partial purification by sequential column chromatographies gavematerial composed of 71% polysaccharides and 29% proteins. Thesugar moiety consisted of mainly xylose, glucose and arabinose,the sum of their contents being more than 76% of the total carbohydrates.The protein moiety consisted of mainly glycine and serine, whichaccounted for more than 40% of the total amino acid residues. (Received June 9, 1984; Accepted November 12, 1984)     

Water-soluble glucans from the seed of Coix lacryma-jobi var. ma-yuen

The water-soluble major polysaccharides from the seed of Coix lacryma-jobi var. ma-yuen eluted as a broad peak by gel filtration on Sepharose CL-2B. The mixture (CS-Glucan) was resolved into 7 glucans by HPLC on the column of Asahi-Pak GS-510 + GS-320. Similarities were observed between M, shown in the gel filtration profile and the elution volume in HPLC. Methylation analysis indicated that the ethanol-fractionated CS-glucan contained 4-O- and 4,6-di-O-substituted glucosyl residues. ¹H and ¹³C NMR data accorded with the results of methylation analysis, and the glycosidic linkages were shown to have an α-configuration. Thus, CS-glucan contained (1 → 4) linked α-d-glucans to which are attached glucosyl side chains at O-6 of the main chain in a similar way to amylopectin. Each purified glucan was shown to have different absorption maxima ( > 550 nm or 530 nm) in the iodine reaction. The results of the methylation analysis and of the pullulanase digestion suggest that the 550 nm-glucan has a lower branching frequency and shorter side chains than the 530 nm-glucan. Although CS-glucan was found to have weak anti-complementary activity, HPLC-purified > 550 nm-glucan was found to be more potent than the 530 nm-glucan. Thus CS-glucan is highly heterogeneous, and the glucans which form a tight complex when tested with iodine, generally tend to have considerable anti-complementary activity.     

Nitrate and Other Anions in the Rice Phloem Sap

The anionic composition was determined for pure rice phloemsap which had been collected from brown planthopper styletsby cutting them with a YAG laser beam. The most abundant inorganicanion was Cl^– at 52.1 mM. PO₄^3– and SO₄^2–were found at 8.1 mM and 1.8 mM, respectively. NO₃^– waspresent at 1.9 mM when the rice had been grown with nutrientsolution containing 0.35 m of NO₃^– The phloem sap alsocontained malic, succinic and citric acid at 7.3, 3.0 and 3.2mM respectively. Small amounts of other organic acids were alsofound. (Received October 4, 1984; Accepted December 14, 1984)     

A Study on Erythrocyte Membrane Plasmalogen in Myotonic Dystrophy

Phospholipid classes that included plasmalogens of erythrocyte membranes in seven myotonic dystrophy (MyD) patients and seven normal controls were analyzed by HPLC. No significant difference in phospholipid classes was found between patients with MyD and normal controls, but there was a visible difference in peak profiles of compounds of the phosphatidylethanolamine class. In the study of plasmalogens, we used two preparation methods: exposure to HCl and deacylation with mild alkaline. The area ratio of the plasmalogen form to the diacyl form in the phosphatidylethanolamine class of MyD erythrocyte membranes was significantly lower than that of normal controls. Fatty acid analyses showed that fatty acids of both phosphatidylethanolamine subclasses have less unsaturation in MyD.