Random Amplified Polymorphic DNA Variation among and within Selected Ixora (Rubiaceae) Populations and Mutants

Random amplified polymorphic DNA (RAPD) analysis was used tostudy variation among and within selectedIxora (Rubiaceae) populationsand mutants. Six populations of I. congesta yielded identicalbanding patterns suggesting genetic uniformity of this species.However, six populations of I. coccinea varieties (three red-flowered,two yellow-flowered and one red-flowered wild-type) exhibitedinfraspecific differences in RAPD profiles. Small and largeleaves of an atavistic mutant cultivar of I. coccinea were alsosubjected to RAPD analysis. An extra band was amplified in thelarge leaves that was absent in small leaves, suggesting thatthe phenotypic alteration in this taxon is due to genetic mutationrather than epigenetic changes. Similarly, an extra band wasdetected in the white sectors of I. Variegated compared to thegreen sectors, suggesting that the shoot apical meristems ofthis cultivar exist as a genetic chimera. DNA gel blot hybridizationwas performed to confirm the specificities of selected bands.Our study indicates that differences among individuals of variouspopulations and mutants may be detected using RAPD markers.Copyright 1999 Annals of Botany Company Ixora L., variegated variety, RAPD fingerprinting, DNA gel blot, intraspecific genetic similarity, atavistic mutant.     

Reconstitution of Embryo-Like Structures from Sea Urchin Embryo Cells: Distinction Between Cell-Cell and Cell-Substrate Associations

Sea urchin embryos can be dissociated into a suspension of single cells that reconstitute embryo-like structures. When reconstitution is conducted in stationary cultures the first step is attachment of the cells to the culture plate, which requires calcium and metabolic energy but not protein synthesis. We have found that protease treated cells form cell-cell associations in stationary cultures without attaching to the culture plates, and that cell-plate attachments are unaffected by inhibition of protein synthesis. These data suggest that cell surface proteins are needed for cell-plate attachment and that these proteins are present on freshly dissociated cells. We also demonstrated that butanol extracted cells attach to the plates, but do not form functional cell-cell associations unless the butanol extracted material is restored to them. We conclude that sea urchin embryo cells contain two classes of attachment components. The first class functions in the cell-plate attachments, is protease sensitive, and not extracted by butanol; the second class is necessary for cell-cell associations, is protease insensitive, and extracted by butanol. Since protease treated cells reconstitute embryo-like structures without attaching to the culture plates, only the second class of attachment components is necessary for embryo reconstitution.     

EFFECTS OF RESIDUAL TOOTHPASTE FLAVOR ON FLAVOR PROFILES OF COMMON FOODS AND BEVERAGES

Because toothpaste and other menthol/surfactant‐containing products have residual effects, researchers should ensure that enough time has elapsed between use of toothpaste and evaluation of food products. In this study, orange juice, coffee, sausage and processed cheese were profiled under controlled conditions and at 4, 12, 30 and 60 min after panelists brushed with a strongly mentholated toothpaste. Residual effects of the toothpaste at 4 min reduced several aromatic attributes, but did not affect most fundamental taste or texture attributes. A mint aromatic was observed in some food products after toothpaste use, even after 12 min. Chemesthetic attributes were diminished when a product was presented within 12 min of brushing. Results suggested that the amount of time needed between brushing and tasting depended on the food product. Orange juice, an acidic beverage, required at least an hour's delay; fatty, solid foods could be tasted almost immediately after toothbrushing if provided a warm‐up sample first.     

The Role of Maturation Drying in the Transition from Seed Development to Germination: IV. PROTEIN SYNTHESIS AND ENZYME ACTIVITY CHANGES WITHIN THE COTYLEDONS OF RICINUS COMMUNIS L. SEEDS

Drying of immature seeds of Ricinus communis L. cv. Hale (castorbean) during the desiccation-tolerant phase of development causesthem to germinate upon subsequent rehydration. This desiccation-inducedswitch from development to germination is also mirrored by achange in the pattern of soluble and insoluble protein synthesiswithin the cotyledons of the castor bean. Following rehydrationof seeds prematurely dried at 40 d after pollination (DAP),cotyledonary proteins characteristic of development (e.g. storageproteins) are no longer synthesized; hydrolytic processes resultingin their degradation commence (after 12 h) in a manner similarto that observed following imbibition of the mature seed. Apattern of protein synthesis recognizable as germination/growth-associatedoccurs; premature drying has elicited a redirection in metabolismfrom a developmental to a germinative mode. Desiccation is alsorequired for the induction (within cotyledons of 35 DAP seeds)of enzymes involved in protein reserve breakdown (leucyl ß-naphthylamidase;LeuNAase) and lipid utilization (isocitrate lyase; ICL), anevent intimately associated with the post-germinative (growth)phase of seedling development. Thus, at a desiccation-tolerantstage of development, premature drying results in the suppressionof the developmental metabolic programme and a permanent switching-onof the germination/growth metabolic programme. Key words: Desiccation, metabolism, seed development, seed germination, castor bean, cotyledons     

Some early works on heliconiine butterflies and their biology (Lepidoptera, Nymphalidae)

In the course of a survey of the history of the study of Heliconiinae, particularly their biology, in the eighteenth and nineteenth centuries it is shown that Heliconius nigromarginatus (Goeze) and H. pallescens (Goeze) are nomina oblita , and that H. cinereofuscus (Goeze) is not, as always supposed, a species in its own right. A new name is proposed for H. melpomene cybele (Cramer). The origin and application of some of Linnaeus' names is discussed.
Illustrations of Heliconius by Seba, Clerck, Petiver and Cramer show that three species, melpomene, erato and doris have been polymorphic at least since the middle of the eighteenth century.
The Indo-Australian genus Cethosia should probably be included in the Heliconiinae.