Effect of Benzyladenine on DNA, RNA, Protein, and Chlorophyll Contents in Intact Bean Leaves: Differential Responses to Benzyladenine According to Leaf Age

Benzyladenine (BA) was applied to intact bean (Phaseolus vulgaris) leaves at different stages of their growth. Changes in the amounts of cellular constituents resulting from the different treatments were followed and compared. RNA, protein, and chlorophyll contents, dry weight, fresh weight, and leaf area per single leaf continued increasing when leaves were treated with BA from an early stage, whereas in untreated leaves all these values levelled off or declined with advancing age. Besides these changes, BA treatment induced an increase in the DNA content. Changes in RNA content was more remarkable in response to application or deprival of BA treatment than the corresponding ones in protein and chlorophyll contents. The pattern of response to BA varied greatly according to the age at which the leaf received the treatment. As leaves aged, they lost the ability to increase their area and fresh weight in response to BA. However, continuous treatment with BA from an early stage kept the leaves young and able to respond.     

Heterogeneous Distribution of Membrane Cholesterol at the Attachment Site of Cryptosporidium muris to Host Cells

ABSTRACT. Distribution of membrane cholesterol at the attachment site of Cryptosporidium muris was investigated by freeze-fracture cytochemistry using a polyene antibiotic filipin. Since the host plasma membrane enveloped C. muris , the inner and outer membranes were continuous with the parasite plasma membrane at the annular ring and with host membrane at the dense band, respectively. Although many filipin-cholesterol complexes were observed on the plasma membrane of host cells and parasites, a line showing no complexes was evident at the above two membrane junctures. These observations indicate that parasitic infection of C. muris altered the organization of membrane cholesterol.     

The Arctic Warbler Phylloscopus borealis– three anciently separated cryptic species revealed

The Arctic Warbler Phylloscopus borealis breeds across the northern Palaearctic and northwestern‐most Nearctic, from northern Scandinavia to Alaska, extending south to southern Japan, and winters in Southeast Asia, the Philippines and Indonesia. Several subspecies have been described based on subtle morphological characteristics, although the taxonomy varies considerably among different authors. A recent study (T. Saitoh et al. (2010) BMC Evol. Biol. 10 : 35) identified three main mitochondrial DNA clades, corresponding to: (1) continental Eurasia and Alaska, (2) south Kamchatka, Sakhalin and northeast Hokkaido, and (3) most of Japan (Honshu, Shikoku, Kyushu). These three clades were estimated to have diverged during the late Pliocene to early Pleistocene (border at c. 2.6 million years ago). Differences in morphometrics have also been reported among members of the three clades (T. Saitoh et al. (2008) Ornithol. Sci. 7 : 135–142). Here we analyse songs and calls from throughout the range of the Arctic Warbler, and conclude that these differ markedly and consistently among the populations representing the three mitochondrial clades. Kurile populations, for which no sequence data are available, are shown to belong to the second clade. To determine the correct application of available scientific names, mitochondrial DNA was sequenced from three name‐bearing type specimens collected on migration or in the winter quarters. Based on the congruent variation in mitochondrial DNA, morphology and vocalizations, we propose that three species be recognized: Arctic Warbler Phylloscopus borealis (sensu stricto) (continental Eurasia and Alaska), Kamchatka Leaf Warbler Phylloscopus examinandus (Kamchatka (at least the southern part), Sakhalin, Hokkaido and Kurile Islands), and Japanese Leaf Warbler Phylloscopus xanthodryas (Japan except Hokkaido).     

Studies on Unequal Cleavage in Sea Urchins II. Surface Differentiation and the Direction of Nuclear Migration

Cortical features of the meso- and macromeres differ from those of the micromeres in sea urchins. At the end of the 8-cell stage, the four animal cells have a continuous row of vesicles lining the free surface of the cell by transmission electron microscopy (TEM) and the nuclei and the resulting mitotic apparatuses (MA) remain at the cell centers and eventually divide equally into eight mesomeres. In the four vegetal cells, narrow gaps can be seen in the vesicular rows near the vegetal pole. The resting nuclei migrate to these gaps and on forming the spindles, they point directly to the gaps. The result is formation of vesicle-free micromeres and vesicle-covered macromeres by unequal divisions.     

Ovarian development and vitellogenesis in the sawfly,Athalia rosae ruficornis Jakovlev (Hymenoptera,Tenthredinidae)

Summary

Ovarian development in Athalia rosae ruficornis Jakovlev (Hymenoptera: Tenthredinidae) is described. Number of nurse cells per egg chamber is most often around 60 (close to 63 according to the 2ⁿ–1 rule), but in many cases it deviates from this number significantly. Two major yolk proteins [vitellins: large (apparent molecular weight 160–170 kD) and small (48–50 kD] were identified by SDS-PAGE. Western blotting and immunochemical detection using polyclonal antibodies prepared against each of the vitellins revealed that adult female but not male (both haploid and diploid) hemolymph contains vitellogenins corresponding to these vitellins. Vitellogenins become detectable in the hemolymph of late pupae, and vitellins one day later in the oocytes of adults. Transplantation of immature ovaries into the adult male abdomen caused not only significant accumulation of vitellins in the oocyte but also appearance of small amounts of hemolymph vitellogenins in host males. Injection of homogenate of immature ovaries also caused appearance of small amounts of hemolymph vitellogenins in host males.     

Isolation and characterization of microsatellite DNA loci for endangered fish,Japanese huchen (Hucho perryi)

Japanese huchen, Hucho perryi, is an endangered fish in Japan. In order to promote a conservation program for this species, it is necessary to evaluate its genetic diversity and population genetics. For this purpose, we designed 15 primers containing dinucleotide microsatellite regions and examined their allelic variation using a total of 23 wild individuals collected from two different localities. Eight loci showed moderate allelic variation ranging from two to four alleles, with expected heterozygosities from 0.043 to 0.548. These markers will be useful for the assessment of genetic variation for this species.     

Citrus limonoid by-products as insect control agents

Limonoids are a group of chemically related bitter tetranortriterpene derivatives found predominantly in Rutaceae and Meliaceae plants (Ourison et al., 1964). Interest in the Rutaceae limonoids has centered around limonoid removal from consumable citrus products. For example, bitterness in citrus juices (as well as in other citrus products) due to limonoids has become an increasingly serious economic problem (Wilson & Crutchfield, 1968; Sinclair, 1972). Interest in the Meliaceae limonoids, on the other hand, has centered on their efficacy as pest control and/or antitumor agents (Kubo & Klocke, 1981, 1982; Nakanishi, 1977, 1980). For example, azadirachtin, isolated from several Meliaceae trees, has proven to be a potent natural product against a myriad of insect and nematode pests (Warthen, 1979). In fact, we have isolated azadirachtin from the fresh fruit of Azadirachta indica as a potent insect ecdysis inhibitor against four agricultural pest insects with artificial diet feeding assay (Kubo & Klocke, in litt).     

DEGRADATION AND FORMATION OF SULFOLIPID OCCURRING CONCURRENTLY WITH DE- AND RE-GENERATION OF CHLOROPLASTS IN THE CELLS OF CHLORELLA PROTOTHECOIDES

1. It has been demonstrated that when the cells of Chlorella protothecoidesare grown mixotrophically under illumination in a medium richin nitrogen source (urea) and poor in glucose, the normal greencells are obtained, while in a medium rich in glucose and poorin the nitrogen source, entirely chlorophyll-less cells withprofoundly degenerated plastids ("glucose-bleached" cells) areproduced, irrespective of whether in the light or in darkness.The "glucose-bleached" cells turn green with regeneration offully organized chloroplasts when incubated in a nitrogen-enrichedmedium in the light ("light-greening"), while in the dark theybecome pale green with formation of only partially organizedchloroplasts ("dark-greening"). When, on the other hand, thegreen cells are transferred into a medium enriched with glucose,they are bleached fairly rapidly with degeneration of chloro-plastsin the light as well as in darkness ("bleaching"). Using ³⁵Sas a tracer, investigations were made on the changes of contentsof the algal cells in sulfolipid and other sulfur compoundsduring the processes of the greening and bleaching.
2. By determiningthe radioactivities of chromatographically separatedsulfur-containingcompounds of the uniformly ³⁵S-labeled green("G") and "glucose-bleached"("W") cells, it was found thatthe concentration of a speciesof sulfolipid (discovered byBENSON et al.) as well as thoseof glutathione, sulfotriosesand most of the other sulfur-containingcompounds were at least5 times higher in the "G" cells thanin the "W" cells, whilesulfoquinovosyl glycerol was presentin approximately equalamounts in the two types of cells.
3. Phospholipidcontents and compositions in the two types of algalcells werefound to be practically identical.
4. The sulfolipid contentof algal cells increased and decreasedalmost in parallel withthe processes of greening and bleaching,respectively.
5. Studyingthe mode of incorporation of radiosulfate into varioussulfurcompounds of algal cells during the processes of "light-anddark-greening" and "bleaching" (lasting about 70 hr), itwasfound that active ³⁵S-incorporation into sulfolipid occurredthroughout the process of "light-greening," while in the "dark-greening"and "bleaching" the active incorporation abruptly ceased afterthe initial 24 hr period of experiments. It was suggested thatthe biosynthesis of the sulfolipid is closely related to theformation of photosynthetic apparatus in chloroplast.
6. Whenthe ³⁵S-labeled green cells were bleached in a medium containingno radiosulfate, the ³⁵S-sulfolipid and most of other ³⁵S-sulfurcompounds decreased markedly but the ³⁵S-sulfoquinovosyl glycerolincreased considerably. It was inferred that the deacylationof the sulfolipid, a surfactant lipid, with formation of watersoluble sulfoquinovosyl glycerol may be a cardinal event ofbleaching process, causing a disintegration of the intact architechtureof photosynthetic apparatus.
7. Based on these observations itwas concluded that the sulfolipidis an integral component ofphotosynthetic structure.

¹This work was partly reported at the Symposium on Biochemistryof Lipids, sponsored by the Agricultural Chemical Society ofJapan, Sapporo, July, 1964.