The telocentric tandem repeat at the p-arm is not conserved in Mus musculus subspecies

Mouse chromosomes, with the exception of the Y chromosome, are telocentric. The telomere at the p-arm is separated from the centromere by the tL1 sequence and TLC tandem repeats. A previous report showed that the TLC array was also conserved in other strains of the subgenus Mus. These results suggest that the TLC arrays promote the stable evolutionary maintenance of a telocentric karyotype in the subgenus Mus. In this study, we investigated the degree of conservation of TLC arrays among a variety of wild-derived inbred strains, all of which are descendants of wild mice captured in several areas of the world. Genomic PCR analysis indicates that the sequential order of telomere-tL1 is highly conserved in all strains, whereas tL1-TLC is not. Next, Southern blot analysis of DNAs isolated from a panel of mouse subspecies showed both Mus musculus domesticus and Mus musculus castaneus subspecies possess TLC arrays. Unexpectedly, this repeat appears to be lost in almost all Mus musculus musculus and Mus musculus molossinus subspecies, which show a clear geographic divide. These results indicate that either other unknown sequences were replaced by the TLC repeat or almost all M. m. musculus and M. m. molossinus subspecies do not have any sequence between the telomere and minor satellites. Our observation suggests that the TLC array might be evolutionarily unstable and not essential for murine chromosomal conformation. This is the first example of the subspecies-specific large genome alterations in mice.     

Glutathione S‐transferase π complexes with and stimulates Na+,K+‐ATPase

Glutathione S‐transferase (GST) was found to complex with the Na⁺,K⁺‐ATPase as shown by binding assay using quartz crystal microbalance. The complexation was obstructed by the addition of antiserum to the α‐subunit of the Na⁺,K⁺‐ATPase, suggesting the specificity of complexation between GST and the Na⁺,K⁺‐ATPase. Co‐immunoprecipitation experiments, using the anti‐α‐subunit antiserum to precipitate the GST‐Na⁺,K⁺‐ATPase complex and then using antibodies specific to an isoform of GST to identify the co‐precipitated proteins, revealed that GSTπ was complexed with the Na⁺,K⁺‐ATPase. GST stimulated the Na⁺,K⁺‐ATPase activity up to 1.4‐fold. The level of stimulation exhibited a saturable dose–response relationship with the amount of GST added, although the level of stimulation varied depending on the content of GSTπ in the lots of GST received from supplier. The stimulation was also obtained when recombinant GSTπ was used, confirming the results. When GST was treated with reduced glutathione, GST activity was greatly stimulated, whereas the level of stimulation of the Na⁺,K⁺‐ATPase activity was similar to that when untreated GST was added. When GST was treated with H₂O₂, GST activity was greatly diminished while the stimulation of the Na⁺,K⁺‐ATPase activity was preserved. The results suggest that GSTπ complexes with the Na⁺,K⁺‐ATPase and stimulates the latter independent of its GST activity. Copyright © 2012 John Wiley & Sons, Ltd.     

Inhibition of Sporulation of Genus Bacillus by Various Microbial Protease Inhibitors

Several analogs modifying the 6-methoxy-2-methoxymethyl-3-(3,4-methyienedioxyphenyl)-1,4-benzodioxan-7-yl group of haedoxans were synthesized and their insecticidal activity was examined. 2-(2,6-Dimethoxyphenoxy)-1-hydroxy-6-(2-methoxy-5-methoxyethoxyphenyl)-3,7-dioxabicyclo-[3.3.0]octane, which lacked the 3-(3,4-methylenedioxybenzyloxy) moiety of the benzodioxanyl group, was not insecticidal, but caused prolonged paralysis of the housefly. A compound replacing the 6-(2-methoxy-5-methoxyethoxyphenyl) by 6-(5-butoxy-2-methoxyphenyl) exhibited insecticidal activity comparable to one thirty-thousandth of that of haedosan A. It became evident that the 1,4-benzodioxane framework charging the 3-(3,4-methylenedioxy)phenyl group is important for the insecticidal activity of haedoxans.     

Cell-Bound Serine Proteinase of Sporulating Cells of Bacillus subtilis

2-Deuterio-2-cyclohexen-l-one, 3-deuterio-2-cyclohexen-l-one and 2-methyl-2-cyclohexen-1-one were reduced by Clostridium La 1 giving a single bioconversion product resulting from reduction of the carbon-carbon double bond. Stereochemistry of the reaction was studied.     

Studies on Oxalacetate Carboxylyase of Pig Heart Muscle

Oxalacetate carboxylyase was extracted from pig heart muscle and purified about 40 fold by means of acid and heat treatments, salting out and three steps of column chromatography. Some properties of the enzyme were studied by manometric and spectrophotometric measurements. The enzyme activity was optimal at pH 7. Km for oxalacetate was 4.3 × 10^?3 m/liter and the activation energy of the enzyme reaction was 15 kcal/m. The enzyme was activated by certain bivalent cations, among which Mn²⁺ was the most effective. Cu²⁺, Hg²⁺, some metal chelating reagents (EDTA, citrate and Oxalate) and pCMB strongly inhibited the enzyme activity. Inhibition by avidin was not observed, suggesting that biotin was not involved in the reaction as the prosthetic group of the enzyme.     

Camellidins,Antifungal Saponins Isolated from Camellia japonica

Two triterpenoid saponins were isolated from an aqueous or a methanolic extract of camellia (Camellia japonica) leaf. They had an antifungal activity characterized by abnormal germination of conidia. These saponins were composed of 3βhydroxy-18β-acetoxy-28-norolean-12-en-16-one or 3β, 8β-dihydroxy-28-norolean-12-en-16-one as aglycon, and d-glucuronic acid, dglucose and two moles of dgalactose as the sugar moiety. The authors have named these new saponins “Camellidin,” which might have value for studies in the fields of phytopathology and biochemistry.     

Efficient and Reproducible Myogenic Differentiation from Human iPS Cells: Prospects for Modeling Miyoshi Myopathy In Vitro

The establishment of human induced pluripotent stem cells (hiPSCs) has enabled the production of in vitro, patient-specific cell models of human disease. In vitro recreation of disease pathology from patient-derived hiPSCs depends on efficient differentiation protocols producing relevant adult cell types. However, myogenic differentiation of hiPSCs has faced obstacles, namely, low efficiency and/or poor reproducibility. Here, we report the rapid, efficient, and reproducible differentiation of hiPSCs into mature myocytes. We demonstrated that inducible expression of myogenic differentiation1 (MYOD1) in immature hiPSCs for at least 5 days drives cells along the myogenic lineage, with efficiencies reaching 70–90%. Myogenic differentiation driven by MYOD1 occurred even in immature, almost completely undifferentiated hiPSCs, without mesodermal transition. Myocytes induced in this manner reach maturity within 2 weeks of differentiation as assessed by marker gene expression and functional properties, including in vitro and in vivo cell fusion and twitching in response to electrical stimulation. Miyoshi Myopathy (MM) is a congenital distal myopathy caused by defective muscle membrane repair due to mutations in DYSFERLIN. Using our induced differentiation technique, we successfully recreated the pathological condition of MM in vitro, demonstrating defective membrane repair in hiPSC-derived myotubes from an MM patient and phenotypic rescue by expression of full-length DYSFERLIN (DYSF). These findings not only facilitate the pathological investigation of MM, but could potentially be applied in modeling of other human muscular diseases by using patient-derived hiPSCs.     

CYP26A1 and CYP26C1 cooperatively regulate anterior-posterior patterning of the developing brain and the production of migratory cranial neural crest cells in the mouse

The appropriate regulation of retinoic acid signaling is indispensable for patterning of the vertebrate central nervous system along the anteroposterior (A-P) axis. Although both CYP26A1 and CYP26C1, retinoic acid-degrading enzymes that are expressed at the anterior end of the gastrulating mouse embryo, have been thought to play an important role in central nervous system patterning, the detailed mechanism of their contribution has remained largely unknown. We have now analyzed CYP26A1 and CYP26C1 function by generating knockout mice. Loss of CYP26C1 did not appear to affect embryonic development, suggesting that CYP26A1 and CYP26C1 are functionally redundant. In contrast, mice lacking both CYP26A1 and CYP26C1 were found to manifest a pronounced anterior truncation of the brain associated with A-P patterning defects that reflect expansion of posterior identity at the expense of anterior identity. Furthermore, Cyp26a1-/-Cyp26c1-/- mice fail to produce migratory cranial neural crest cells in the forebrain and midbrain. These observations, together with a reevaluation of Cyp26a1 mutant mice, suggest that the activity of CYP26A1 and CYP26C1 is required for correct A-P patterning and production of migratory cranial neural crest cells in the developing mammalian brain.