LIGHT-INDUCED HIGH-AMPLITUDE SWELLING AND SHRINKING IN ISOLATED SPINACH CHLOROPLASTS

It was found that light accelerates the swelling of spinachchloroplasts suspended in a solution containing NaCl and Tris-HCl,and that, in about 60 min, the swollen chloroplasts begin toshrink rapidly. The volume of chloroplasts reached, on swelling,270 per cent of the original volume on the average and thenshrank to 17 per cent. The rate of swelling and the maximumvolume were affected markedly by the tonicity of NaCl. NH₄Cldid not affect the volume changes, while phenazine methosulfateaccelerated the swelling remarkably. The relationship betweenphotoshrinkage and this light-induced high-amplitude swellingwas discussed. (Received April 2, 1966; )     

Development of microsatellite markers for the crown‐of‐thorns starfish Acanthaster planci

We isolated nine polymorphic microsatellites from the crown‐of‐thorns starfish, Acanthaster planci. These loci provide one class of highly variable genetic marker as the number of alleles ranged from three to 12 and the observed and expected heterozygosities ranged from 0.130 to 0.783 and from 0.163 to 0.862, respectively. We consider that these loci are potentially useful for detailing the genetic structure and gene flow among A. planci populations.     

Gene flow of Acanthaster planci (L.) in relation to ocean currents revealed by microsatellite analysis

Population outbreaks of the coral-eating starfish, Acanthaster planci , are hypothesized to spread to many localities in the Indo-Pacific Ocean through dispersal of planktonic larvae. To elucidate the gene flow of A. planci across the Indo-Pacific in relation to ocean currents and to test the larval dispersal hypothesis, the genetic structure among 23 samples over the Indo-Pacific was analysed using seven highly polymorphic microsatellite loci. The F -statistics and genetic admixture analysis detected genetically distinct groups in accordance with ocean current systems, that is, the Southeast African group (Kenya and Mayotte), the Northwestern Pacific group (the Philippines and Japan), Palau, the North Central Pacific group (Majuro and Pohnpei), the Great Barrier Reef, Fiji, and French Polynesia, with a large genetic break between the Indian and Pacific Oceans. A pattern of significant isolation by distance was observed among all samples ( P =  0.001, r  = 0.88, n  = 253, Mantel test), indicating restricted gene flow among the samples in accordance with geographical distances. The data also indicated strong gene flow within the Southeast African, Northwestern Pacific, and Great Barrier Reef groups. These results suggest that the western boundary currents have strong influence on gene flow of this species and may trigger secondary outbreaks.     

Pigments and a UV-absorbing substance in corals and a blue-green alga living in the Great Barrier Reef

Pigments and UV-absorbing substances in several species of coralsand a blue-green alga harvested in the environs of the GreatBarrier Reef were studied by measuring the in vivo reflectionspectra of intact samples and absorption spectra of their waterextracts with a recording spectrophotometer set on a biologicalresearch vessel. Red, pink, mauve and violet colors of fourspecies of Acropora were thus found to be due to differencesin the relative content of two pigments designated as P(pigment)-560and P-590, according to the maximum wavelength in mµ oftheir major absorption peaks. A yellow species of Acropora anda red species of Pocillopora contained different pigments, P-500and P-480, respectively. All these five species of corals contained,in addition to the above pigments, a UV-absorbing substancehaving an absorption peak near 320 mµ. The contents ofthis substance in the organisms seemed to be very high as judgedfrom its band height relative to band heights of the visiblepigment bands. Blue-green algal cells harvested near the sameenvirons contained a similar UV-absorbing substance in additionto phycobilin pigments. The spectral characteristics of thepigments and the UV-absorbing substance found in the coralsand alga are presented in this paper. ¹The present study was carried out in cooperation with Drs.F. T. HAXO, P. HALLDAL and S. W. JEFFREY on the research vessel,R. V. "Alpha Helix", of University of California during the1966 expedition to the Great Barrier Reef, North Queensland,Australia, and was supported by the National Science Foundationof the U. S. A. (Received December 3, 1968; )     

OCCURRENCE OF MUCOPOLYSACCHARIDES IN THE EARLY DEVELOPMENT OF THE SEA URCHIN EMBRYO AND ITS ROLE IN GASTRULATION

The occurrence of acid mucopolysaccharides in the early development of the sea urchin embryo was studied by histochemical stainings as well as by autoradiographic methods. By histochemical methods acid niucopolysacchdride was demonstrated at the vegetal region in the early stage of gastrulation as a globular structure. Experiments with ³⁵S-labeled sulfate which was incorporated into acid mucopolysaccharides confirmed the result obtained by histochemical observation. It was revealed that sulfate polysaccharide in the vegetal region moved toward the blastocoel in parallel with the shedding of the primary mesenchyme cells. When the incorporation of sulfate into the acid mucopolysaccharides was inhibited by selenate, the primitive gut development was remarkably repressed. The substance seems to be indispensable for smooth cell movements essential for the gastrulation of sea urchin embryo.     

VINYL PHEOPORPHYRIN A5 IN THE INNER SEED COATS OF PUMPKINS

The pigments contained in the inner seed coats of Cucurbitapepo, C. maxima and C. moschata were investigated spectroscopicallyusing both intact tissues and their ether extracts. The pigment(s) contained in C. pepo and C. maxima was inferred to be "protochlorophyll"and/or Mg vinyl pheoporphyrin a₅ which are indistinguishablefrom each other by mere spectroscopic observations. The coatsof C. moschata were found to contain Mg-free vinyl pheoporphyrina₅ which has so far been reported to exist only in some Chlorellamutants. The spectra of these pigments in intact tissues wereremarkably different from those of the ether extracts, indicatingthe profound difference in their physical states in vitro andin vivo. It was discussed that the "protochlorophyll b" reportedearlier by SEYBOLD and EGLE might have been vinyl pheoporphyrina₁. (Received July 14, 1960; )     

Ultracytochemical localization of H＋—adenosine triphosphatase activity in autophagic vacuoles induced by vinblastine in rat liver

H^-adenosine triphosphatase (H^ -ATPase) activity was demonstrated cytochemically in autophagic vacuoles(AVs) of rat hepatocytes using a modification of the method for the demonstration of neutral p-nitrophenyl phosphatase(p-NPPase) activity[1].When an inhibitor of H^ -ATPase,N-ethylmaleimide (NEM) or 4,4‘-diisothiocyanostilbene-2,2‘disulfonic acid,disodium salt (DIDS) was included in the incubation medium the enyzme activity was abolished indicating that p-NPPase demonstrated in this study represents H^ -ATPase.Autophagy was induced by a single intraperitoneal injection of vinblastine sulfate(VBL).The number of AVs increased remarkably in hepatocytes from 40 min after VBL treatment.H^ -ATPase activity was observed mainly on the membranes of lysosomes and AVs.However,early forms of AVs containing only incompletely digested material showed no H^ -ATPase activity.Most AVs revealing a positive reaction seemed to be in advanced stages of development.Acid phosphatase acticity was demonstrable in mature but not in early forms of AVs.The present investigation showed that membranes of advanced stage AVs possess an H^ -ATPase which may be derived from lysosomal membranes.