SALT EFFECTS ON SWARMERS OF DUNALIELLA VIRIDIS TEOD

1. Dunaliella viridis Teodoresco thrives equally well in solutions of NaCl 1 to 4 mol and pH 6 to 9. 2. The organism is sensitive to calcium and magnesium, especially in acid medium. 3. Calcium and magnesium are antagonistic. In a molar solution of NaCl the antagonistic relation Mg:Ca is 4 to 5. In a 4 molar solution of NaCl the proportion becomes many times as great (20:1). 4. Although the strains used in this investigation did not occur in sea water concentrates, the increase in the antagonistic ratio Mg:Ca in which they can live closely paralleled the changes in this ratio which take place when sea water evaporates. 5. The other organisms which occurred in the cultures each show a specific relation to Ca and Mg. 6. The size of the cells of Dunaliella does not decrease with increasing NaCl content.     

EFFECTS OF COLCEMID ON HYDRA VIRIDIS WITH MULTIPLE-PEDUNCLE GRAFTS

The effect of Colcemid on multiple-graft Hydra viridis containing three peduncles (3p) grafted in tandem is reported. At grafting, the apical member of a 3p animal is a foot-less host, the middle member, an isolated peduncle, and the proximal member, a foot-bearing peduncle. In different experimental situations all three members are treated with Colcemid, the host member alone is treated, or the host member is not treated but the others are. Control animals have only non-treated members. Head and foot regeneration on graft pieces and the formation of waists and separations at the borders between these pieces are monitored and the significance of differences between frequencies tested by Chi square. Head formation on the middle and proximal peduncles is promoted by Colcemid when all pieces are treated, but animals with treated host pieces have significantly higher frequencies of heads on their non-treated proximal pieces than other experimental and control animals. Animals with Colcemid-treated proximal peduncles do not have significantly more heads on the most proximal peduncle compared to controls. Colcemid does not alter the frequency of foot formation significantly on the host peduncles of animals in the different categories, but foot formation is increased on the middle pieces of animals with three treated pieces and on animals with middle and proximal treated pieces. The rate of waist formation and graft separation is retarded when all three or just the host piece is treated, but not when only the middle and proximal pieces are treated. The direct action of Colcemid on nerves and on dividing cells may be responsible for these effects.     

STRUCTURE AND REPRODUCTION OF THE ALGAL SYMBIONTS OF HYDRA VIRIDIS1

The algal symbionts of Hydra viridis are found within vacuoles of the gastrodermal digestive cells of the host. Electron microscopy reveals that the symbionts possess cell walls, and that their reproductive cycle follows the general pattern of free-living Chlorella. Nuclear and chloroplast divisions arc followed by formation of new cell walls, the Golgi apparatus being quite active during cell wall synthesis. Autospores are released when the parent wall ruptures. The autospores are then usually segregated into separate animal vacuoles. Remnants of the ruptured parent wall persist in the vacuoles for an indefinite period. The ruptured parent walls curl at the breakage clefts, forming double-layered scroll-like structures. The fate of these wall remnants has not been firmly established. Long-term starvation of the animals does not result in a detectable change in the structure of the symbionts, and they continue to divide and to store carbohydrate as starch grains.     

贻贝（Perna viridis）超氧化物歧化酶的纯化及部分性质研究

采用５５－６０℃热处理,硫酸铵分级深沉和ＤＥＡＥ－ＳｅｐｈａｒｏｓｅＦＦ柱层析将贻贝Ｃｕ,Ｚｎ－ＳＯＤ纯化到均一程度。每１００ｇ鲜贻贝肉可得到ＳＯＤ制品,总活力３６８９ｕ,比活力７８２ｕ／ｍｇ,回收率为２１％。测得该酶分子量为３２ｋＤ,亚基分子量约为１６．４ｋＤ,最大紫外吸收波长为２６８ｎｍ,,贻贝Ｃｕ,Ｚｎ－ＳＯＤ具有一定的耐热性,较强的抗酸、抗碱及抗脲性。     

Inflammation-induced miR-802 promotes cell proliferation in cholesteatoma

Cholesteatoma is a destructive and abnormal skin growth consisting of keratinizing squamous epithelium in the middle ear. Its molecular mechanisms remain poorly understood. Here, we found that the NF-κB inflammatory signaling pathway was highly activated in cholesteatoma. NF-κB activation increased the expression of microRNA-802 (miR-802) and chromatin immunoprecipitation assays showed that P65 could uniquely bind to miR-802 promoter. miR-802 overexpression promoted keratinocyte cell proliferation and cell cycle progression, while inhibition of miR-802 decreased these effects. From computational analysis and luciferase report assays, miR-802 directly repressed PTEN expression by targeting its 3′-UTR. Our results demonstrate that the NF-κb/miR-802/PTEN signaling pathway plays an important role in the development of cholesteatoma.     

QUANTITATIVE STUDIES OF PINNULE DEVELOPMENT IN THE FERNS ADIANTUM RADDIANUM AND CHEILANTHES VIRIDIS

Pinnule development was investigated in two fern species, Adiantum raddianum Presl cv. Decorum and Cheilanthes viridis (Forsk.) Swartz, by using clearings to facilitate the recording of mitotic divisions. Both species were found to possess a marginal meristem. This meristem consists of both a marginal row of large initials and a submarginal meristematic zone. The marginal meristem in these ferns is responsible for establishing the layers of the lamina, providing new cells which by enlargement will expand the pinnule, establishing general pinnule form, initiating the procambial stands, and forming the false indusia. The cells of the submarginal meristem were found to divide parallel to the pinnule margin more frequently if they were to become ground tissue, while dividing perpendicular to the margin more frequently if they were to become procambial. Details of vein dichotomies were also studied. Perimeter expansion was found to be associated with dichotomy of the veins, and venation pattern was found to be correlated with leaf form. The marginal meristem is active from the time of pinnule initiation until the pinnule reaches about 50% of its final length or width. Leaf development in leptosporangiate ferns resembles the traditional concept of development in angiosperms somewhat more than it does the more recent concepts. It is clear, though, that there is not a high degree of convergence in the marginal growth of fern and angiosperm leaves.     

NOTES ON THE BREEDING BEHAVIOUR OF THE PARADISE FLYCATCHER (TERPSIPHONE VIRIDIS PLUMBEICEPS)

Milewski, A. V. 1978. Diet of Serinus species in the southwestern Cape, with special reference to the Protea Seedeater. Ostrich 49:174-184.

The diet of the Protea Seedeater Serinus leucopterus was assessed by opportunistic observation of feeding occasions throughout the distribution of the bird. The Protea Seedeater feeds mainly on seed of a wide range of plant species. It takes the large seed of Proteo more frequently than it does any other food item. The diet of the Protea Seedeater consists essentially of food items and types similar to those taken by six sympatric and partly sympatric congeners, which are also mainly dating. However, its diet differs quantitatively, each species taking different food types, such as achenes and seed kernels, with different frequency.     

LEARNING AS A FACTOR IN DIET SELECTION BY ELYSIA VIRIDIS (MONTAGU) (OPISTHOBRANCHIA).

Elysia viridis (Montagu) occurs naturally in populations feedingon the fleshy, siphonalean green alga Codium or on the coarse,filamentous green alga Chaetomorpha. Only about half of theE. viridis transferred from Codium to Chaetomorpha in the laboratorywere able to learn to feed on this alga. Handling time decreasedsignificantly during the learning-period. All E. viridis transferredfrom Chaetomorpha to Codium in the laboratory were able to learnto feed on the latter alga. Handling time also decreased withexperience in these animals. Ingestive conditioning occurredin animals transferred from Chaetomorpha to Codium. These animalshad to go through a learning-period again when they were offeredChaetomorpha after 6–9 weeks with Codium Ingestive conditioningwas also evident from preference experiments; animals preferredthe food they had been kept on prior to the experiments. Thesefindings are discussed in relation to optimal diet theory. (Received 14 December 1987; accepted 22 March 1988)     

STRONG PROBABILITY OF LETHAL TOXICITY IN THE BLUE-GREEN ALGA MICROCYSTIS VIRIDIS LEMMERMANN1

Lethal toxicity (intraperitoneal, mouse) was examined in relation to Species composition of samples containing bloom-forming Microcystis populations from natural waters and correlated with toxicity of laboratory strains of four Microcystis formas and species. Toxicity was not always associated with the presence of M. aeruginosa f . aeruginosa Elenkin. A sample with almost all cells of M. aeruginosa f . aeruginosa showed no toxicity, However samples comprised of a high percentage of M. viridis Lemmermann often showed lethal toxicity. Toxicity tests were done on culture strains M. aeruginosa f aeruginosa, M. aeruginosa f flos-aquae Elenkin , M. viridis and M. wesenbergii Kamárek. All five cultured strains of M. viridis were found to be toxic, while only one out of nine strains of M. aeruginosa f . aeruginosa was toxic. Six strains of M. wesenbergii showed no toxicity, It is recommended that attention should be paid to the occurrences and possibility of toxic bloom of M. viridis from the standpoint of water management and public health .     

SOUND PRODUCTION IN THE BLUE-GREEN DAMSELFISH,CHROMIS VIRIDIS (CUVIER, 1830) (POMACENTRIDAE)

ABSTRACT

Sound production is widespread in coral reef fish of the family Pomacentridae. As commonly found in other teleosts, damselfish emit calls in agonistic and courtship contexts. In this paper, evidence of sound production by the blue-green damselfish Chromis viridis is presented for the first time. The recorded sounds consisted of clicks produced during agonistic interactions.