The effect of fat body on the differentiation in vitro of wing imaginal discs ofDrosophila melanogaster

Summary The effect of suboptimal levels of -ecdysone on the differentiation in vitro ofDrosophila melanogaster wing discs was enhanced by the addition of larval fat body to the cultures. However, similar experiments with -ecdysome showed no enhancement. It is suggested that a partial conversion of -ecdysone to -ecdysone by the fat body may well account for these results.     

Stress-induced peptide release from rat intermediate pituitary

Summary We tested the hypothesis that acute restraint stress results in ultrastructural evidence for enhanced release of alpha-melanocyte-stimulating hormone (-MSH) and -endorphin from the intermediate lobe (IL) of the rat pituitary. Measurements of plasma -MSH-and -endorphin-immunoreactivity (ir) were used to confirm ultrastructural findings. Plasma -MSH-ir was elevated after 20 and 30 min of restraint while plasma -endorphin-ir peaked 10 min after the onset of restraint. Ultrastructural analysis revealed a decrease in the content of secretory granules within IL cells of stressed rats. Analysis of Golgi-related immature secretory granules in IL cells indicated that new peptide synthesis was not enhanced after 30 min of restraint. These results confirm previous studies showing and elevation of plasma -endorphin and -MSH-ir during acute restraint. Furthermore, these results indicate that quantitative analysis at the ultrastructural level can be used to assess peptide release from IL secretory cells during stress.     

Elucidation of Structure of Lipid A from the Marine Gram-Negative Bacterium Pseudoalteromonas haloplanktis ATCC 14393T

The chemical structure of lipid A, from the marine -proteobacterium Pseudoalteromonas haloplanktis 14393, a main product of lipopolysaccharide hydrolysis (1% AcOH), was determined using chemical methods and NMR spectroscopy. The lipid A was shown to be -1,6-glucosaminobiose 1,4-diphosphate acylated with two (R)-3-hydroxyalkanoic acid residues at C3 and C3 and amidated with one (R)-3-hydroxydodecanoyl and one (R)-3-dodecanoyloxydodecanoyl residue at N2 and N2, respectively.     

Mast cells in rat dermis and jejunal lamina propria show a five-fold difference in unit granule volume

Summary The cytoplasmic granules of mast cells have a periodic multimodal size distribution in which the volumes of individual granules are integral multiples of the intermodal distance, a volume defined as the unit granule or ₁. In this study, we used two 3-month-old male rats to analyze two classical mast cell subpopulations, dermal connective tissue-type mast cells and jejunal lamina propria mucosal mast cells, for the morphometric characteristics of their cytoplasmic granules. Both and the mean volume of individual cytoplasmic granules were much smaller in dermal than in jejunal mast cells (ratios of 1:5.5 and 1:4.2, respectively), but dermal mast cells contained 150% more granules per cell than did jejunal mast cells. The two types of mast cells did not differ significantly in total cell volume, nucleus volume, aggregate volume of cytoplasmic granules per cell or numbers of unit granules comprising a granule of mean volume. These findings add unit granule volume to the list of phenotypic characteristics which express significant variation in anatomically distinct populations of mast cells.     

Chromosomal location of the active NORs in theSteropleurus martorelli complex

The chromosomal location of the active NORs has been analyzed by a silver impregnation procedure in theSteropleurus martorelli complex. A primary NOR, which is always present at the first meiotic prophase, has been found in each of the four described races. In addition to this, all races possess one or two secondary NORs which are less active than the former and can be occasionally shown. Usually only one of the two homologous chromosomes has been found to be involved with nucleolus organisation.These results are discussed in relation to hypotheses on the chromosome differentiation of this species complex.     

Neural crest cells and skeletogenesis in vertebrate embryos

Conclusions Evidently it is the circumstances of tissue association which are important with regard to the differentiation of NC-derived cells into primary cartilage and membrane bone. Tissue interactions of this sort apparently do not play a role in the differentiation of secondary cartilage, where simply theposition of NC-derived cells and their progeny within the early membrane bone primordium determines whether or not those cells will subsequently express a secondary chondrogenic potential.Whether we are considering the type of tissue association generated or the specification of cell positioning, both are controlled by the parameter of NC cell migration. Thus disturbances in the conditions of migration, for instance retarded migration or incorrect timing, will generate anomalies of cranio-facial morphogenesis and of skull development, (Johnstonet al., 1977; Morriss & Thorogood, 1978). Furthermore, as phylogenetic differences in (skull) form are generated by changes in developmental mechanisms, simple quantitative changes in such parameters as NC migration and proliferation will have profound evolutionary consequences (see, for example, Kollar & Fisher, 1980).This review started by asking the question How, in a developmental sense, does one build a skull? That question has not been answered but a few suggestions have been provided as to the rules of the developmental programme whereby the various skeletal tissues are laid down in a skull-specific pattern. It seems that these rules can be defined in terms of timing, circumstances of tissue association and spatial positioning of cells. A comprehensive identification and fuller recognition of rules such as these is, I propose, a pre-requisite to understanding this particular developmental programme.     

Efficiency of doxorubicin handling by isolated hepatocytes is a valuable indicator for restored cell function

Pig liver is a possible source of hepatocytes for extracorporeal bio-artificial liver devices. In order to evaluate recovered hepatocyte function following enzymatic isolation, we developed a cytochemical method that is based on the capacity of hepatocytes to sequester the anthracycline antitumour drug doxorubicin within intracellular acidic compartments. Doxorubicin is a naturally fluorescent molecule. Thus, the process of drug concentration within hepatocytes can be visualized in living conditions by fluorescence microscopy. Porcine hepatocytes harvested from heart-beating donors were grown either as isolated cell suspensions or as tissue monolayers. Immediately after isolation and at fixed culture times, cells were incubated with 0.1mM doxorubicin in Hanks' balanced salt solution for 10min at 37°C in 5% CO₂-humidified atmosphere and observed by fluorescence microscopy. Parallel electron microscopy was performed to compare fluorescence data with general cell morphology. To monitor lysosomal acidification capacity, the fluorescent pH-sensitive vital dye LysoSensor-Blue was used. Doxorubicin fluorescence showed different patterns of nuclear and cytoplasmic staining, according to the time allowed for cell recovery and the culture method. In particular, cytoplasmic fluorescence changed from a diffuse staining, that could be observed after cell isolation and in hepatocyte suspensions, to a punctate perinuclear and pericanalicular fluorescence detectable in fully recovered hepatocyte monolayers. This study indicates that the doxorubicin-fluorescence test may be considered a simple and rapid procedure for assessing hepatocyte functional condition. It may provide valuable and real time guidelines for judging the correct way these cells are to be collected, preserved and utilized for clinical purposes.     

The ultrastructure of the accessory sex organs of the male rat

Summary The fine structure of the nuclei of epithelial cells of the dorsal lobe of the rat prostate were studied after administration of three different antiandrogenic compounds.The nucleolus appears to undergo a progressive disorganisation with partial fragmentation and dispersion of its normal components. Different types of intranuclear inclusions were found.The various alterations observed were often encountered within the same section. This may indicate that the nuclear alterations occur in the same compartment of the cell, and represent a dysfunction of integrated biochemical events occurring within this compartment.The findings support a view that the stimulatory secretory effect of androgens is mediated via a secretory center, located within the nucleolusassociated chromatin. Within this secretory center, the initial steps of the secretory process, the binding of the DHT receptor complex to DNA is assumed to occur.     

The transport of class I major histocompatibility complex antigens is determined by sequences in the α1 and α2 protein domains

The transport of human-mouse hybrid class I histocompatibility antigens has been studied in a mutant human cell line, 174 × CEM.T2 (T2). T2, a somatic cell hybrid of human B- and T-lymphoblastoid cell lines (B-LCL and T-LCL, respectively), synthesizes HLA-A2 and HLA-B5 glycoproteins, but expresses only low levels of A2 and undetectable levels of B5 at the cell surface. We have previously shown that the products of human class I genes introduced into T2 by transfection behave like the endogenous HLA-B5 glycoproteins, while the products of mouse class I alleles similarly introduced are transported normally to the cell surface. We have now determined that the surface expression of class I glycoproteins in T2 depends on the origin of the ₁ and ₂ domains. Human (HLA-B7) and mouse (H-2D ^p ) hybrid class I genes, encoding the leader, ₁, and ₂ sequences of one species fused to the ₃, transmembrane, and cytoplasmic domains of the other, were transfected into T2. Normal surface expression of the hybrid class I molecule was observed in T2 only when the leader, ₁, and ₂-encoding exons were derived from the mouse gene. The reciprocal construct, encoding human leader, ₁, and ₂ domains fused to the mouse ₃, transmembrane, and cytoplasmic regions, resulted in biosynthesis of a hybrid glycoprotein which was not transported to the cell surface. The products of both constructs were expressed normally in control cells. The effects of glycosylation on class I antigen transport were also studied using mutant class I constructs with altered glycosylation sites. Two mutant B7 genes encoding either an extra glycosylation site at position 176 or no glycosylation sites were transfected into T2. These mutant products were expressed at the cell surface in control cells, but were synthesized and not surface-expressed in T2. These data demonstrate that the HLA/H-2 transport dichotomy in T2 is a function of the origin of the ₁ and/or ₂ domains of the class I glycoprotein, and is not a reflection of glycosylation differences between the human and mouse molecules. Offprint requests to: P. Cresswell.     

Differential location of regulatory and nonregulatory trehalases inCandida utilis cells

The isolation of vacuoles by density gradient centrifugation of protoplast lysates fromCandida utilis cells showed a high specific activity for nonregulatory trehalase in vacuoles whereas the regulatory trehalase activatable by phosphorylation behaves as a cytoplasmic enzyme. The vacuolar trehalase is a glycoprotein that can be precipitated by Con A-Sepharose. Treatment of this enzyme with endo H reduced its reactivity with the lectin without loss of enzyme activity and decreased its apparent molecular weight by gel filtration.Abbreviations cAMP adenosine 3, 5-cyclic monophosphate - Con A Concanavalin A - CP buffer 10mM sodium citrate-phosphate pH 6.8 - endo H endo--N-acetyl glucosaminidase H - PMSF phenyl-methyl-sulphonylfluoride - PNPG p-nitrophenyl--glucoside - PNPP p-nitrophenyl-phosphate     

α-tocopherol inhibits oxidative stress induced by cholestanetriol and 25-hydroxycholesterol in porcine ovarian granulosa cells

The cytotoxicity of oxysterols including 7-ketocholesterol, -epoxide, cholestanetriol and 25-hydroxycholesterol and the possible protecting effect of -tocopherol on cholestanetriol and 25-hydroxycholesterol-induced cytotoxicity were investigated in primary cultures of porcine ovarian granulosa cells. Cell viability as determined by % trypan blue staining and mitochondrial function as determined using 3-[4,5-dimethylthiazol-2-yl]-2,5- diphenyltetrazolium bromide (MTT) reduction were decreased significantly after 24 h exposure to 2.5 M -epoxide, cholestanetriol and 25-hydroxycholesterol. 7-ketocholesterol (2.5 M) did not affect cell viability or mitochondrial function under the same culture conditions. The specific activities of catalase and superoxide dismutase, two antioxidant defense enzymes were increased significantly (p < 0.01) following 24 h exposure to 2.5 M concentrations of cholestanetriol while only superoxide dismutase was increased in 25-hydroxycholesterol-treated cells (p < 0.001). Specific activity of glutathione peroxidase was unchanged relative to control cells. Levels of thiobarbituric acid reactive substances remained unchanged after exposure to 7-ketocholesterol, -epoxide, cholestanetriol, 25-hydroxycholesterol and cholesterol. Administration of 1 M -tocopherol to the culture medium significantly improved cell viability and restored both superoxide dismutase and catalase activities to control levels in cholestanetriol -treated cells and only superoxide dismutase in 25-hydroxycholesterol-treated cells. These studies suggest that the cytotoxic nature of physiologically relevant concentrations of cholestanetriol and 25-hydroxycholesterol in granulosa cells is in part due to oxidative stress, but it may be reduced in the presence of a-tocopherol.     

Genetic analysis of certain in vitro and in vivo parameters in pigeonpea (Cajanus cajan L.)

Summary Studies on callus growth and shoots/cotyledon, using seven different genotypes of pigeonpea and their hybrid progenies, revealed continuous variation for these traits. Hence, the type of gene action influencing in vitro cell proliferation and differentiation has been investigated in a diallel analysis of seven pigeonpea genotypes. Highly significant average heterosis was recorded for callus growth and seed yield/plant. In general, the F₁ hybrids which showed heterosis for callus growth also exceeded their better parent for yield/ plant. Combining ability analysis revealed both additive and non-additive gene effects for callus growth, while number of shoots/cotyledon was mostly governed by non-additive gene effects. The genotype, ICP 7035, was the best general combiner for callus growth and shoot forming capacity of cotyledons. Two cross combinations, 7186×6974 and 7035×T-21, showed maximum SCA effects for callus growth and shoots/cotyledon. Callus dry weight was positively correlated with seed yield/plant and seedling weight. The strong positive association of callus growth with seed yield indicates the possibility of using this system for mass screening and selection of superior hybrids.     

Distribution of land snails (Mollusca, Gastropoda, Pulmonata) on the island of Gran Canaria (Canary Islands) in relation to protected natural areas

The oceanic island of Gran Canaria, part of the Macaronesian Archipelagos, is highly deteriorated, a situation which has had negative repercussions for endemic species. A recent law, however, established 32 Protected Natural Areas in an attempt to remedy the problem. In the present work we show the distribution of common (non-endemic) land snails on the island. The snails were largely introduced by man over the past five centuries. A comparison between the distribution of the endemic land snails and the protected areas shows the latter to be generally adequate. We also suggest some modifications to the law in two Areas and the addition to the list of two further Areas so as to guarantee protection of several endemic species currently under threat (according to the criteria of the IUCN): 2 critically endangered, Hemicycla saulcyi saulcyi and Napaeus isletae, 2 vulnerable, Theba arinagae and Obelus despreauxii, and 1 lower risk, Hemicycla berkeleyi.     

Evolutionary Morphology, Innovation, and the Synthesis of Evolutionary and Developmental Biology

One foundational question in contemporarybiology is how to `rejoin evolution anddevelopment. The emerging research program(evolutionary developmental biology or`evo-devo) requires a meshing of disciplines,concepts, and explanations that have beendeveloped largely in independence over the pastcentury. In the attempt to comprehend thepresent separation between evolution anddevelopment much attention has been paid to thesplit between genetics and embryology in theearly part of the 20th century with itscodification in the exclusion of embryologyfrom the Modern Synthesis. This encourages acharacterization of evolutionary developmentalbiology as the marriage of evolutionary theoryand embryology via developmental genetics. Butthere remains a largely untold story about thesignificance of morphology and comparativeanatomy (also minimized in the ModernSynthesis). Functional and evolutionarymorphology are critical for understanding thedevelopment of a concept central toevolutionary developmental biology,evolutionary innovation. Highlighting thediscipline of morphology and the concepts ofinnovation and novelty provides an alternativeway of conceptualizing the `evo and the `devoto be synthesized.     

Supramolecular Structure Formed from H-Bonding of Ferrocenyl Carbonyl Propanoic Acid and 4,4'-Bipyridine

Selective recognition in the title compound, (C₁₄H₁₄FeO₃)₂ (C₁₀H₈N₂), between ferrocenyl carbonyl propanoic acid and 4,4'-bipyridine through strong O–-HN intermolecular hydrogen bonds results in a novel supramolecular architecture. Its crystal structure has been solved by single-crystal X-ray diffraction methods while its characterization has been studied by IR and DSC.     

Implications of sea mining for the Red Sea environment

Populations of Pistia stratiotes L., a pleustonic macrophyte, have been surveyed in two ponds of different hydrochemical nature. Based on the rosette form, two biotypes were distinguished. They are provisionally designated as Compact and loose varieties. They occur as sympatric populations in the ponds. A comparison of the diameter of the rosette, root length, 5th leaf length & breadth and length & number of inflorescences, followed by tests of significance, confirm their distinctiveness. In vegetative propagation, they propagate true. The comparison of the biotypes is extended to biomass, productivity allocation, pH of the cell saps, chlorophyll, nucleic acids, total free amino acid (TNPS) content of the leaves and total nitrogen, crude protein and phosphorous in whole plants.     

Ultrastructure of the protonephridial system of regenerating Stenostomum sp. (Plathelminthes,Catenulida)

Summary The ultrastructure of the flame bulbs, protonephridial capillaries and duct of fully developed and regenerating Stenostomum sp. is described. Flame bulbs are formed by a single cell whose nucleus is located basally or laterally to the weir. The weir is formed by a single row of transverse ribs connected by a thin membrane, apparently of extracellular matrix. Internal leptotriches arise from the proximal cytoplasm and extend in a (usually) single row along the weir and into the lumen of the distal cytoplasmic tube. Many or all leptotriches do not fuse with the distal cytoplasm. Two cilia are each anchored in the proximal cytoplasm by a cross-striated vertical and lateral rootlet, the latter bent forward and extending for some distance into one of the two cytoplasmic cords along the weir. Each cord contains the lateral rootlet in its proximal part, as well as many microtubules. The distal cytoplasmic tube contains two (longitudinal) junctions, i.e. lines of contact between cell processes of the same, terminal cell. Occasionally, more than two junctions were seen, apparently due to branches of the terminal cell in contact with each other. Flame bulbs join capillaries lined by several canal cells type I, containing few or no microvilli but lateral flames. Such capillaries join a duct (or ducts?) lined by canal cells type II with many long microvilli. The large protonephridial duct is lined by numerous cells with lateral flames and many long microvilli. In regenerating tissue (10.5 hours after cutting) some flame bulbs were free, i.e. not connected to capillaries, and some capillaries openly communicated with the surrounding intercellular space. In the presence of a single row of ribs in the weir, of internal leptotriches, and of vertical and lateral ciliary rootlets, the flame bulb of Stenostomum sp. resembles that of other Plathelminthes much more closely than hitherto thought. The species differs from non-catenulid plathelminths mainly in the large number of glandular cells lining the large protonephridial ducts, in the transverse orientation of the ribs in the weir and in the presence of only two cilia in the flame.     

N-glycan structures of murine hippocampus serine protease, neuropsin, produced in Trichoplusia ni cells

N-glycans of neuropsin (serine protease in the murine hippocampus) expressed in Trichoplusia ni cells were released from the glycopeptides by digestion with glycoamidase A (from sweet almond), and the reducing ends of the oligosaccharides were reductively aminated with 2-aminopyridine. The derivatized N-glycans were separated and structurally identified by a two dimensional high-performance liquid chromatography (HPLC) mapping technique on two kinds of HPLC columns. Fourteen different major N-glycan structures were identified, of which 6 were high-mannose type (9.1%), and the remaining 8 were paucimannosidic type. The presence of insect specific N-glycan structures containing both 1,3- and 1,6- di-fucosylated innermost N-acetylglucosamine residue (23.3%), as below, was also confirmed by 600 MHz ¹H-NMR spectroscopy.     

Reproduction of the calanoid copepod Calanus propinquus in the southern Weddell Sea,Antarctica: observations in laboratory

Reproduction of the dominant Antarctic copepod Calanus propinquus was studied in February–April, 1989 aboard the R.V Dmitry Mendeleev during cruise N° 43 to the Weddell Sea. Single females were kept at 0 °C in the laboratory for 56 days with abundant food concentration (above 300 µg C l^–1 of Platymonas viridis). Females released clutches at night at 2–3 day intervals. Most clutches contained from 10 to 40 eggs, mean 37.3 eggs female^–1. Average carbon content of an egg was 0.37 ± 0.05 µg C. The maximum daily egg production rate of 30–50 eggs female^–1 d^–1 was observed for the first 3 days of the laboratory incubation, corresponding to 3.7–6.2% body C. The state of gonadal development of females showed the decline of the reproductive season in late February. The data suggest that egg laying in the region under study starts in December and lasts until March. The state of ovarian maturation, changes in vertical distribution and biochemical body composition of females suggest the possibility of two-year life cycle in C. propinquus in the southern Weddell Sea.     

Topography of the subunits of Micrococcus lysodeikticus F1-ATPase

Summary The combined use of proteolytic digestion and lactoperoxidase catalyzed labelling with [¹²⁵I] applied to membrane-bound or soluble pure F₁-ATPase from Micrococcus lysodeikticus has allowed us to establish the topography of its , , and subunits within the protein molecule and with respect to the plane of the membrane.The subunit is most externally located to the membrane bilayer looking towards the cytoplasmic face, a position consistent with its proposed catalytic role. The and subunits lie in an intermediate layer between the subunits and the membrane, in which the subunit occupies a central position within the F₁-ATPase molecule in contact with the subunit. The subunit appears to be tightly bound to the F₀ component of the ATPase complex, probably buried in the membrane bilayer. A molecular arrangement of M. lysodeikticus ATPase is proposed that, taking into account the subunit stoichiometry _{3 3 2 2} (MW 420 000), accommodates the role assigned to each subunit and most, if not all, the known properties of this bacterial energy-transducing protein.