BIOCHEMICAL CHANGES IN YEAST DURING SPORULATION. II. ACETATE METABOLISM

Acetate metabolism was studied with Saccharomyces cerevisiae diploid strain G2-2 in sporulating culture, asporogenic diploid strains 3c × a and 3c × 3a, and respiratory deficient haploid strain 3c (asporogenic). Acetate in a sporulating medium was utilized by sporogenic and asporogenic diploid yeasts linearly with time. Activities of aconitase, NADP-linked isocitrate dehydrogenase, and succinate dehydrogenase initially increased in the cell-free homogenate of either strain. Activity of glucose-6-phosphate dehydrogenase decreased. Isocitrate lyase activity increased remarkably in the sporogenic strain but not in the asporogenic strain. The rate of production of ¹⁴CO₂ from ¹⁴C-1-acetate was accelerated more than from ¹⁴C-2-acetate in intact cells of the sporogenic strain during sporulating culture. Fractionation of radioactive cell substances showed remarkable lipid synthesis. Accumulation and reutilization of cold acid-soluble precursor substances occurred during sporogenesis. The role of glyoxylate and tricarboxylate cycle enzymes in sporulation is discussed.     

One new and one newly recorded species of the genus Amraica Moore, 1888 (Lepidoptera: Geometridae: Ennominae) from China,with diagnoses of the Chinese species

The genus Amraica Moore, 1888 in China is reviewed. In addition to the four species and three subspecies already known, one new species, A. prolata sp. nov. is described and one newly recorded species, A. ferrolavata ( Walker, 1863 (imprint 1862) ) is redescribed. The generic characters, based on all species, are summarized. Illustrations of external features and genitalia are presented.     

A NEW ELASMOSAURID PLESIOSAUR FROM THE UPPER CRETACEOUS OF FUKUSHIMA, JAPAN

Abstract:  A new genus and species of an elasmosaurid plesiosaur, Futabasaurus suzukii , is described based on a partial skeleton from the Inoceramus amakusensis Zone (Lower Santonian, Upper Cretaceous) of the Irimazawa Member of the Tamayama Formation, Futaba Group, in Fukushima Prefecture, Japan. The new taxon is characterized by a number of characters such as the wide space between the orbit and external naris, posterior extension of the interclavicle, relatively long humerus and prominent femoral muscle scar. The holotype includes a partial skull and mandible, posterior cervicals to sacrals, ribs, clavicular arch, pelvic girdle and four limbs. The remains are mostly in articulation, and exhibit evidence of predation/scavenging by sharks. The distribution of elasmosaurid species in the circum-Pacific region remains unclear due to the lack of diagnostic materials. The occurrence of F. suzukii is geographically and stratigraphically significant, because it allows species-level comparison; as a diagnosable elasmosaurid specimen, F. suzukii is the first and the oldest from the northern Pacific.     

Identification of genes regulated by dark adaptation and far‐red light illumination in roots of Arabidopsis thaliana*

Roots in the soil are illuminated by far‐red (FR) light passed through plant tissues in the daytime, and are in complete darkness at night. To evaluate whether gene expression of roots is affected by a dark‐FR light cycle, gene expression profiles were analysed for dark‐adapted versus light‐grown plants and for FR light‐illuminated versus dark‐adapted plants using the RIKEN Arabidopsis full‐length cDNA microarray (containing approximately 7000 independent, full‐length cDNA groups). Among candidate dark‐ and FR‐regulated genes, several were further analysed. Eleven dark‐inducible and five dark‐repressed genes were characterized. Almost all the dark‐inducible and –repressed genes were oppositely regulated by FR light illumination. The functions of dark‐ and FR‐responsive genes and the significance of FR light‐regulated gene expression in roots under ground are discussed.     

Molecular cloning and characterization of the AVR-Pia locus from a Japanese field isolate of Magnaporthe oryzae

In order to clone and analyse the avirulence gene AVR-Pia from Japanese field isolates of Magnaporthe oryzae , a mutant of the M. oryzae strain Ina168 was isolated. This mutant, which was named Ina168m95-1, gained virulence towards the rice cultivar Aichi-asahi, which contains the resistance gene Pia. A DNA fragment (named PM01) that was deleted in the mutant and that co-segregated with avirulence towards Aichi-asahi was isolated. Three cosmid clones that included the regions that flanked PM01 were isolated from a genomic DNA library. One of these clones (46F3) complemented the mutant phenotype, which indicated clearly that this clone contained the avirulence gene AVR-Pia . Clone 46F3 contained insertions of transposable elements. The 46F3 insert was divided into fragments I–VI, and these were cloned individually into a hygromycin-resistant vector for the transformation of the mutant Ina168m95-1. An inoculation assay of the transformants revealed that fragment V (3.5 kb) contained AVR-Pia . By deletion analysis of fragment V, AVR-Pia was localized to an 1199-bp DNA fragment, which included a 255-bp open reading frame with weak homology to a bacterial cytochrome- c -like protein. Restriction fragment length polymorphism analysis of this region revealed that this DNA sequence co-segregated with the AVR-Pia locus in a genetic map that was constructed using Chinese isolates.     

Studies in the Mitosis of Euglena I. On the Chromosome Cycle of Euglena viridis Ehrbg.

The chromosome cycle in the vegetative division of Euglena viridis was investigated. The seeming chromatin granules in the interphase nucleus are in reality thread structures, paired and very loosely twisted. Each component of the paired threads is called a chromatid, and consists of a fine thread of even thickness, the chromonema.
In the prophase, linear contraction and thickening of the chromatids occurs by means of the spiralization of them. In the later prophase, the coiled chromonema splits into two finer strands which show the plectonemic spiral. At the metaphase, the chromosomes are arranged in the form of an equatorial ring, encircling the median portion of the elongated endosome. Nearly all of the chromosomes have a submedian or a sub-terminal and a few of them have a terminal kinetochore. In the early anaphase, separation of the sister chromosomes takes place beginning at the kinetochore. The spindle fibres in the metaphase and anaphase were not observed. The two stranded spiral in the chromosomes is separated into distinct components by the uncoiling in the later telophase, and they are transformed, in the interphase nucleus, into the paired chromatids.