Formation of P1, P2-dinucleoside 5′-pyrophosphates under potentially prebiological conditions

Summary Organic pyrophosphates such as UppA and NAD are formed when a solution containing a nucleotide, a nucleoside 5q1/xxlarge8242.gif" alt="prime" align="BASELINE" BORDER="0">-polyphosphate, Mg²⁺ and imidazole are allowed to dry out. We suggest that this synthesis may have occured concurrently with oligonucleotide formation.Abbreviations Im Imidazole - CDI 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride - EDTA ethylenediaminetetraacetic acid - A adenosine - U uridine - p_nA adenosine 5q1/xxlarge8242.gif" alt="prime" align="BASELINE" BORDER="0">-poly-phosphate containing n phosphate residues - pU uridine 5q1/xxlarge8242.gif" alt="prime" align="BASELINE" BORDER="0">-phosphate - AppA P₁,P₂-diadenosine 5q1/xxlarge8242.gif" alt="prime" align="BASELINE" BORDER="0">-pyrophosphate - UppA P₁-(uridine 5q1/xxlarge8242.gif" alt="prime" align="BASELINE" BORDER="0">)-P₂-(adenosine 5q1/xxlarge8242.gif" alt="prime" align="BASELINE" BORDER="0">)-pyrophosphate - ImpA adenosine 5q1/xxlarge8242.gif" alt="prime" align="BASELINE" BORDER="0">-phosphorimidazolide - NMN nicotinamide mononucleotide - NAD nicotinamide-adenine dinucleotide     

The mass culture of Dunaliella viridis (Volvocales,Chlorophyta) for oxygenated carotenoids : laboratory and pilot plant studies

The biology, and hence the mass culture, of Dunaliella viridis closely follows that of Dunaliella salina, which is successfully mass cultured for the production of q743/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-carotene. Both algae can grow at extremely high salinities and light intensities. They co-exist in the coastal salt lake, Hutt Lagoon, Western Australia. In contrast to D. salina, D. viridis does not accumulate large amounts of q743/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-carotene, producing only up to 0.7% of mixed carotenoids (lutein, zeaxathin, other oxygenated carotenoids and q743/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-carotene), compared to D. salina's ca 10% dry wt of mainly q743/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-carotene. However, in laboratory experiments, D. viridisgrew much faster and to much higher cell densities than D. salina, and attained levels of mixed carotenoids similar to those of D. salina (ca 13 mg L^–1 carotenoid). Preliminary experiments in outdoor ponds were much less promising. Harvesting by chemical flocculation was as effective as with D. salina, but extraction of carotenoids directly into vegetable oil proved inefficient. When incorporated into feed, caretonoids derived from D. viridis pigmented hen eggs acceptably. Extrapolating from laboratory results, and using costing derived from D. salina technology, the cost of production of mixed oxygenated carotenoids from D. viridis was similar to that for the production of q743/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-carotene from D. salina, at ca $A500 kg^–1.     

Dynamics of carbon assimilation by St Lawrence estuary phytoplankton at the end of summer

This study presents data of in situ measurements of inorganic carbon assimilation by phytoplankton communities of the St Lawrence estuary during the end of summer 1982. We used carboxylase activity measurements (ribulose-1,5-bisphosphate carboxylase, q354/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0"> carboxylases) and the ¹³C/¹²C ratio of phytoplankton organic carbon, expressed as q354/xxlarge8706.gif" alt="part" align="MIDDLE" BORDER="0">¹³C, to study patterns of assimilation. Upper estuary phytoplankton communities showed a smaller turn-over rate in carbon assimilation than lower estuary phytoplankton communities. Carbon assimilation was limited by light intensity in the upper estuary and by CO₂ availability in the lower estuary. In the St Lawrence estuary, stable carbon isotope ratios of phytoplankton organic carbon seemed to be controlled by inorganic carbon availability rather than by phytoplankton metabolism.     

Critical,pupal and adult weights in the size related metamorphosis of the black lyre leafroller ‘Cnephasia’ jactatana

Adult reproductive performance is linked to the period of feeding done by the final instar larva after attainment of a larval critical weight (L_CW). The highest weight attained by a final instar larva is referred to as the larval maximum weight (L_MW) and is the onset of the pre-pupal period. The relationships between L_CW, pupal weight (P_W) and adult weight (A_W) are described as functions of the L_MW. In the leafroller q9632054852gw/xxlarge8216.gif" alt="lsquo" align="BASELINE" BORDER="0">Cnephasiaq9632054852gw/xxlarge8217.gif" alt="rsquo" align="BASELINE" BORDER="0"> jactatana (Walker) (Lepidoptera: Tortricidae) L_CW was dependent on larval size and was approximately 75% of the mean L_MW. L_CW was about 29 mg and 36 mg for male and female larvae of 1.18 mm and 1.20 mm head-capsule width, respectively. Over three successive generations of laboratory rearing, P_W was approximately 30% and 25% lower than the L_MW for males and females, respectively. A_W was consistently about 50% and 40% lower than the P_W for males and females, respectively. The decrease in weight from L_MW to P_W was named as the constant D_P and found to be 0.3 for males and 0.25 for females. The total decrease from L_MW to A_W was the constant D_A and was 0.6 for males and 0.5 for females. The duration of the latent feeding period was positively correlated to P_W and A_W. L_CW may be used to derive quality indices that describe and predict pupal and adult performance.

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quote>Résumé Les performances reproductives sont liées à la période d'alimentation du dernier stade larvaire après l'obtention d'un poids critique (L_CW). Le poids maximal atteint au dernier stade larvaire est défini comme le poids larvaire maximal (L_MW), il correspond au début de la période prénymphale. Les relations entre poids de la chrysalide (P_W) et poids de l'audulte A_W) sont présentées comme des fonctions de L_MW). Chez q9632054852gw/xxlarge8216.gif" alt="lsquo" align="BASELINE" BORDER="0">Cnephasiaq9632054852gw/xxlarge8217.gif" alt="rsquo" align="BASELINE" BORDER="0"> jactatana Walker (Lep. Tortricidae), L_CW dépend de la taille de la chenille et correspond à environ 75% de la valeur moyenne de L_MW. L_CW est respectivement de 29 mg et 36 mg pour les chenilles mâles et femelles dont les capsules céphaliques ont 1,18 et 1,20 mm. Pour 3 générations successives, P_W est environ 30% et 25% inférieur à L_MW des mâles et des femelles. La régression du poids de L_MW à P_W est désignée comme la constante D_P et vaut 0,3 pour les mâles et 0,25 pour les femelles. La régression de L_MW à A_W est désignée comme la régression D_M et vaut 0,6 pour les mâles et 0,5 pour les femelles. La durée de la période d'alimentation latente est liée positivement à P_W et A_W. L_CW peut être utilisé comme indice dérivé décrivant et prédisant les potentialités nymphales et imaginales.quote>     

Hair morphology and the relationships of species inSolanum sect.Basarthrum

The usefulness of features of leaf hairs in distinguishing subgenera and sections is well documented in bothRhododendron andSolanum. In this analysis of the taxa ofSolanum sect.Basarthrum (23 species), and of a sample of closely related taxa from sect.Petota (22 species), it is shown that such features serve to delineate subsectional groups such as series and some species as well. SectionBasarthrum has an unexpected diversity of hair types. Although this group has been characterized by 2-celled q84984316wxv4/xxlarge8220.gif" alt="ldquo" align="MIDDLE" BORDER="0">bayonet hairsq84984316wxv4/xxlarge8221.gif" alt="rdquo" align="MIDDLE" BORDER="0">, more than one half of the taxa in the section bear multicellular q84984316wxv4/xxlarge8220.gif" alt="ldquo" align="MIDDLE" BORDER="0">finger hairsq84984316wxv4/xxlarge8221.gif" alt="rdquo" align="MIDDLE" BORDER="0">, and 3 species also possess branched hairs. Thus, major rearrangements of the species previously assigned to sect.Basarthrum are indicated or supported by pubescence features. The taxa studied from seriesEtuberosa andJuglandifolia (both of sect.Petota) show hair types that a) are relatively primitive for the section, and b) show linkage between sects.Petota andBasarthrum.     

The inheritance of node number and rate of node production in Brussels sprouts

Summary The total vegetative node number, rate of node production and number of sprouts over 13 mm diameter were recorded for 10 F₁ Brussels sprout cultivars and 45 progenies derived by intercrossing and selfing them. Significant differences, resulting from additive gene action, were found between the 10 cultivars and between their progenies for both characters. For total node number there was also evidence of dominant gene action. Total node number and rate of node production were closely correlated as were total node number and the number of harvested sprouts. The factors causing differences in rate of node production are indicated and the relationship of this character to other Brussels sprout yield components is outlined.     

Degradation of pyrimidine bases in Clostridium sticklandii

Resting cells of Clostridium sticklandii took up thymine or uracil, when grown in a medium containing 40 mM serine and 20 mM thymine or uracil. The uptake was much lower, when the cells had been grown in a complex medium. Cell-free extracts from cells grown in the complex medium reduced the two bases to the dihydro compounds and decomposed dihydrothymine to q871n/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-ureidoisobutyrate, as indicated by thin-layer chromatography. Uptake and degradation were stimulated by both NADH and NADPH. Further breakdown did not occur, as ¹⁴CO₂ was not evolved from C-2-labelled thymine or uracil. The rates of pyrimidine uptake and breakdown of C. sticklandii were lower than those reported for C. sporogenes (Hilton et al., 1975).     

Synthesis of two forms of apolipoprotein B by cultured rat hepatocytes

Cultured rat hepatocytes were used to demonstrate that the liver can synthesize two forms of apolipoprotein B. Separation of apolipoprotein B by disc gel electrophoresis indicated that hepatocyte low density lipoprotein contains predominantly apolipoprotein B with an apparent molecular weight of 345,000 ± 5,055. In contrast, the major apolipoprotein B component of hepatocyte very low density lipoprotein is a variant form with a molecular weight of 242,000 ± 2,720. Hepatocyte high density lipoprotein, unlike plasma HDL, also contains apolipoprotein B with an apparent molecular weight of 244,000 ± 2,742. Incorporation of [³H] leucine into hepatocyte apolipoprotein B components suggested de novo synthesis.     

Extensive variation at the α-glycerophosphate dehydrogenase locus in species of waterstriders (Gerridae: Hemiptera)

Variation at the q/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-glycerophosphate dehydrogenase (q/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-Gpdh; EC 1.1.1.8) locus was surveyed in 11 species of waterstriders (Gerridae: Hemiptera) and five other species of aquatic Hemiptera. Species of waterstriders exhibited considerable inter- and intraspecific variation in degree of winglessness. Average heterozygosity (0.401±0.090) and average number of observed electromorphs (5.36±0.96) for the 11 gerrid species were well above values reported for nearly all other insect species surveyed to date. Wing-monomorphic and wing-polymorphic species did not differ in average q/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-Gpdh heterozygosity. Of the three wing-polymorphic species surveyed geographically, two species exhibited marked variation in wing-morph frequencies but homogeneous q/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-Gpdh allele frequencies. The third species exhibited geographically homogeneous q/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-Gpdh and wing-morph frequencies, but no significant association between q/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-Gpdh phenotype and wing morph was observed in any surveyed population. These results are consistent with hypotheses evoking either relaxed purifying selection at the q/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-Gpdh locus in species of Gerridae due to the apparent reduced importance of flight, or selective maintenance of common q/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-Gpdh electromorphs.This work was supported by NSF Grant DEB 76-20967 to Alan H. Brush, funds from the Research Foundation of the University of Connecticut to Carl W. Schaefer, and USPHS Grant GM 21133 to Richard K. Koehn.     

Exogenous glycosaminoglycans (GAG) differentially modulate GAG synthesis by anchorage-independent cultures of the outer cells from neonatal rat calvaria in the absence and presence of TGF-β

In anchorage-dependent (AD) cultures of the outer cell population (OCP) from neonatal rat calvaria, transforming growth factor-q440xw374410p942/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">₁ (TGF-q440xw374410p942/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">) specifically upregulated the synthesis of chondroitin sulfate (CS) proteoglycan (PG) and uncoupled the inhibitory effect of increasing cell density on CS PG synthesis (reference #30). Utilizing the same cell population, we have further examined the possibility that glycosaminoglycans (GAG) known to be synthesized and secreted by bone cells might exert feedback effects on GAG synthesis and/or its stimulation by TGF-q440xw374410p942/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">. Although addition of TGF-q440xw374410p942/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0"> alone stimulated net synthesis of HA and CS in both AD and anchorage-independent (AI) cultures, significant alterations of basal and TGF-q440xw374410p942/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-stimulated GAG synthesis by exogenous GAGs were observed only in AI cultures. In AI cultures exogenously added hyaluronic acid (HA) markedly enhanced the basal synthesis of HA and CS while heparin (H) suppressed the basal synthesis of HA, CS as well as dermatan sulfate (DS). Also, the addition of HA markedly potentiated the stimulation by TGF-q440xw374410p942/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0"> of HA and CS synthesis as did heparan sulfate (HS) for CS and DS synthesis. H suppressed the stimulation of the synthesis of HA, CS and DS by TGF-q440xw374410p942/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">. Overall, our results indicate specific effects of individual GAGs on basal and TGF-q440xw374410p942/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-stimulated GAG synthesis in OCP cultures. We suggest that some of the GAGs in the OCP microenvironment (which with the exception of HA are covalently linked to protein cores of secreted PGs), acting in concert with TGF-q440xw374410p942/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">, may serve as an amplification system for upregulating GAG synthesis in the rapidly growing neonatal calvarium.