Growth regulator induced movement of photosynthetic products into fruits of ;black corinth' grapes

The effect of exogenous growth regulators on movement of assimilates into flowers and young fruits of `Black Corinth' grapes was studied. Clusters were treated with growth regulator and after 0.5 hr to 5 days the leaves above the clusters were exposed to ¹⁴CO₂. Control shoots received ¹⁴CO₂ but no growth regulator. At harvest, counting and radioautographic techniques were used to ascertain amount and distribution of activity in clusters. Clusters were dipped in 4-CPA (4-chlorophenoxyacetic acid), GA₃ (gibberellic acid), or BA (benzyladenine). All berries were heavier than controls within 3 days. Total counts in the fruits were increased by 4-CPA, and the distribution of radioactivity among the sugar, organic acid, and amino acid fractions was usually altered by all treatments. In a time series experiment, within 6 hr after treatment of fruits with GA₃ there was almost an 8-fold increase in total counts relative to the control. After 12 hr there was about a 9-fold and 6-fold increase in counts in tartaric and malic acids, respectively, and in γ-aminobutyric acid, pipecolic acid, and valine increases of 56, 150, and 330%. Radioactivity in fructose was increased 70% in gibberellin-treated clusters over the controls. After 96 hr there were only about 1000 cmp per g fr wt in controls, but there were about 31,000 cpm counts in treated clusters. Treatment of clusters with gibberellin attracted less assimilates into the fruits when shoots had also been sprayed with gibberellin. Dipping portions of clusters in gibberellin increased the movement of ¹⁴C assimilates into the treated portions. Hormonal control of mobilization is discussed.     

Anonymous nuclear DNA markers in the American oyster and their implications for the heterozygote deficiency phenomenon in marine bivalves

A puzzling population-genetic phenomenon widely reported in allozyme surveys of marine bivalves is the occurrence of heterozygote deficits relative to Hardy-Weinberg expectations. Possible explanations for this pattern are categorized with respect to whether the effects should be confined to protein-level assays or are genomically pervasive and expected to be registered in both protein- and DNA-level assays. Anonymous nuclear DNA markers from the American oyster were employed to reexamine the phenomenon. In assays based on the polymerase chain reaction (PCR), two DNA-level processes were encountered that can lead to artifactual genotypic scorings: (a) differential amplification of alleles at a target locus and (b) amplification from multiple paralogous loci. We describe symptoms of these complications and prescribe methods that should generally help to ameliorate them. When artifactual scorings at two anonymous DNA loci in the American oyster were corrected, Hardy-Weinberg deviations registered in preliminary population assays decreased to nonsignificant values. Implications of these findings for the heterozygote-deficit phenomenon in marine bivalves, and for the general development and use of PCR-based assays, are discussed.      

Basolateral plasma membrane localization of ouabain-sensitive sodium transport sites in the secretory epithelium of the avian salt gland

The distribution of Na+ pump sites (Na+-K+-ATPase) in the secretory epithelium of the avian salt gland was demonstrated by freeze-dry autoradiographic analysis of [(3)H] ouabain binding sites. Kinetic studies indicated that near saturation of tissue binding sites occurred when slices of salt glands from salt-stressed ducks were exposed to 2.2 μM ouabain (containing 5 μCi/ml [(3)H]ouabain) for 90 min. Washing with label-free Ringer's solution for 90 min extracted only 10% of the inhibitor, an amount which corresponded to ouabain present in the tissue spaces labeled by [(14)C]insulin. Increasing the KCl concentration of the incubation medium reduced the rate of ouabain binding but not the maximal amount bound. In contrast to the low level of ouabain binding to salt glands of ducks maintained on a freshwater regimen, exposure to a salt water diet led to a more than threefold increase in binding within 9-11 days. This increase paralleled the similar increment in Na+-K+-ATPase activity described previously. [(3)H]ouabain binding sites were localized autoradiographically to the folded basolateral plasma membrane of the principal secretory cells. The luminal surfaces of these cells were unlabeled. Mitotically active peripheral cells were also unlabeled. The cell-specific pattern of [(3)H]ouabain binding to principal secretory cells and the membrane-specific localization of binding sites to the nonluminal surfaces of these cells were identical to the distribution of Na+-K+-ATPase as reflected by the cytochemical localization of ouabain-sensitive and K+-dependent nitrophenyl phosphatase activity. The relationship between the nonluminal localization of Na+-K+-ATPase and the possible role of the enzyme n NaCl secretion is considered in the light of physiological data on electrolyte transport in salt glands and other secretory epithelia.     

Enzymes of Krebs-Henseleit Cycle in Vitis vinifera L: III. In Vivo and In Vitro Studies of Arginase

Ornithine carbamoyltransferase (OCT) activity was detected in extracts from mature leaves, fruit, germinating seeds, and seedlings of Vitis vinifera L. Michaelis-Menten constants for OCT were 3.5 millimolar for carbamyl phosphate and 5.5 millimolar for l-ornithine. Concentrations of l-ornithine greater than 10 millimolar slightly inhibited the enzyme, whereas carbamyl phosphate at concentrations greater than the optimal (about 10 millimolar) did not affect OCT activity. l-Citrulline formation was linear with incubation period for the first 25 minutes and with increasing amounts of enzyme up to an equivalent of about 200 milligrams of fresh tissue. The optimum pH for in vitro OCT activity was between 8.4 and 8.8, and the optimum incubation temperature was 38 C.     

The early life history of two sympatric New Zealand octopuses: eggs and paralarvae of Octopus huttoni and Pinnoctopus cordiformis

This study combined morphological and morphometric information on egg clutches, egg capsules and paralarvae of two sympatric coastal octopuses from New Zealand waters, Octopus huttoni and Pinnoctopus cordiformis, to provide species-specific traits to identify their early life stages obtained from field surveys. Eggs of O. huttoni (2.5 mm length; 1 mm width) were entwined with one another forming strings that ranged from 11 to 25.8 mm in length. Eggs of P. cordiformis (6.4 mm length; 1.5 mm width) were significantly bigger than those of O. huttoni and were grouped in small clusters of about seven eggs. Paralarvae O. huttoni and P. cordiformis differed in hatching size (1.4 mm versus 3.1 mm mantle length), number of suckers per arm (four versus eight), number of lamellae per outer demibranch (five versus ten) and arrangements of chromatophores in the body surface (29 to 59 versus 91 to 179), respectively. The morphological traits described in hatchlings from the laboratory allowed comparisons with field-collected paralarvae, suggesting that such characters were reliable species-specific patterns to enable a consistent differentiation between the early life stages of these two sympatric species, even in the absence of the brooding female.     

Production of endothelial progenitor cells obtained from human Wharton's jelly using different culture conditions

Endothelial progenitor cells (EPC) participate in revascularization and angiogenesis. EPC can be cultured in vitro from mononuclear cells of peripheral blood, umbilical cord blood or bone marrow; they also can be transdifferentiated from mesenchymal stem cells (MSC). We isolated EPCs from Wharton's jelly (WJ) using two methods. The first method was by obtaining MSC from WJ and characterizing them by flow cytometry and their adipogenic and osteogenic differentiation, then applying endothelial growth differentiating media. The second method was by direct culture of cells derived from WJ into endothelial differentiating media. EPCs were characterized by morphology, Dil-LDL uptake/UEA-1 immunostaining and testing the expression of endothelial markers by flow cytometry and RT-PCR. We found that MSC derived from WJ differentiated into endothelial-like cells using simple culture conditions with endothelium induction agents in the medium.