Bioenergetic considerations in the improvement of oil content and quality in oil-seed crops

Summary Production values (PVs), defined as the weight of the end product/weight of the substrate required for carbon skeletons and energy production, were calculated for plant fatty acids. The PVs varied from 0.361 to 0.300 with linolenic acid having the lowest value. In general, the PVs of unsaturated fatty acids were lower than those of saturated fatty acids of similar chain lengths. Using this basic information, PVs of (A) oils from different oilseed crops, based on their standard fatty acid composition and (B) seed biomass with specified oil content and fatty acid composition were calculated. 1/PV gives the glucose required for the biosynthesis of 1 g end product and thus an estimate of the photosynthate requirement for the desired breeding goal can be estimated. Such calculations show that increasing oil percentage in seeds has a maximum energy cost when the increase in oil is associated with a decrease in the amount of carbohydrates where there is no change in protein concentration. Reduction of erucic acid content in the rapeseed oil did not alter its PV. It is inferred that there are no serious bioenergetic constraints in altering the fatty acid composition.     

Gonadotropin and prostaglandins binding sites in rough endoplasmic reticulum and Golgi fractions of bovine corpora lutea.

Highly purified rough endoplasmic reticulum and three subfractions of golgi were prepared from 105,000g pellet of the homogenate by centrifugation in floatation and sedimentation discontinuous sucrose gradients. Highly purified plasma membranes were also prepared from 9,000g pellet of the same homogenates for assessment under the same experimental conditions. Although 5′-nucleotidase, a marker for plasma membranes, was markedly enriched in plasma membranes, very little or none of this enzyme activity was found in other fractions. Very little or no NADH cytochrome c reductase activity, a marker for rough endoplasmic reticulum, was found in fractions other than rough endoplasmic reticulum. Galactosyl transferase, a marker for golgi, was found and enriched in all the fractions; however, enrichment in golgi fractions was higher than in other fractions. Very little or no lysosomal marker activity, i.e., acid phosphatase, was found in rough endoplasmic reticulum or golgi fractions as compared to lysosomes. These marker enzyme data suggested that rough endoplasmic reticulum and golgi fractions were relatively pure with little or no cross contamination with other organelles. The [¹²⁵I]human choriogonadotropin ([¹²⁵I]hCG), [³H]prostaglandin (PG)E₁, and [³H]PGF_2a specifically bound to rough endoplasmic reticulum and golgi fractions in addition to plasma membranes. The enrichments of binding in the former two fractions, in some cases, were as high as plasma membranes itself. The specific binding of some of the ligands was found to be partially latent in rough endoplasmic reticulum and golgi fractions but not in plasma membranes. Marker enzyme data, ratio between bindings and marker enzyme activities (an index of organelle contamination), and partial latency of binding suggest that rough endoplasmic reticulum and golgi fractions intrinsically contain gonadotropin and PGs binding sites.     

Molecular orbital studies on nucleoside analogs. II. Conformation of 6-azapyrimidine nucleosides.

PCILO (Perturbative Configuration Interaction using Localised Orbitals) computations have been carried out for three 6-azapyrimidine nucleosides, 6-azauridine, 6-azacytidine and 6-azathymidine, for both C(2')-endo and C(3')-endo pucker of the sugar ring. The results indicate a syn (chiCN=180 degrees) conformation followed by chiCN=90 degrees and gg conformation for C(3')-endo 6-aza analogs as compareed to the anti (chiCN=0 degrees) and gg conformation preferred by the corresponding pyrimidine nucleosides. For C(2')-endo sugar geometry, 6-azauridine and 6-azacytidine prefer, respectively, chiCN=0 degrees (anti) and phi C(4')-C(5')=60 degrees C (gg) and chiCN-240 degrees (syn) and phi C(4')-C(5')=120 degrees. The corresponding nucleosides, uridine and cytidine, show a preference for syn (chiCN=240 degrees) and gg and anti(chiCN=0 degrees) and gg , respectively. The X-ray crystallographic conformations of 6-azauridine and 6-azacytidine have been attributed to intermolecular hydrogen bonding and crystal packing forces. The results of PMR, CD and ORD studies on 6-azauridine and 6-azacytidine in aqueous solutions are in agreement with the PCILO predictions.     

Single-strand breakage in DNA of Escherichia coli exposed to Cd2+.

When a growing culture of Escherichia coli was exposed to 3 X 10(-6) M Cd2+, 85 to 95% of the cells lost their ability to form colonies on agar plates. Loss of viability was accompanied by considerable single-strand breakage in the DNA, with no detectable increase in double-strand breaks. A direct correlation appeared to exist between the number of single-strand breaks and the concentrations of Cd2+ to which the cells were exposed. Exposure of DNA in vitro to a Cd2+ concentration of 3 X 10(-6) M or higher, followed by sedimentation in alkaline sucrose gradients, demonstrated no single-strand breaks. Cadmium-exposed cells recovered viability when incubated in Cd2+-free liquid medium containing 10 mM hydroxyurea. During the early period of recovery, there was a lag in the incorporation of labeled thymidine, but cellular DNA, at least in part, appeared to be repaired.     

Mitochondrial haplogroup N1a phylogeography,with implication to the origin of European farmers

Background  

Tracing the genetic origin of central European farmer N1a lineages can provide a unique opportunity to assess the patterns of the farming technology spread into central Europe in the human prehistory. Here, we have chosen twelve N1a samples from modern populations which are most similar with the farmer N1a types and performed the complete mitochondrial DNA genome sequencing analysis. To assess the genetic and phylogeographic relationship, we performed a detailed survey of modern published N1a types from Eurasian and African populations.     

From obesity to cancer: a review on proposed mechanisms

Nowadays, obesity is considered as a serious and growing global health problem. It is documented that the overweight and obesity are major risk factors for a series of noncommunicable diseases, and in recent years, the obesity‐cancer link has received much attention. Numerous epidemiological studies have shown that obesity is associated with increased risk of several cancer types, including colon, breast, endometrium, liver, kidney, esophagus, gastric, pancreatic, gallbladder, and leukemia, and can also lead to poorer treatment. We review here the epidemiological and experimental evidences for the association between obesity and cancer. Specifically, we discuss potential mechanisms focusing how dysfunctional angiogenesis, chronic inflammation, interaction of proinflammatory cytokines, endocrine hormones, and adipokines including leptin, adiponectin insulin, growth factors, estrogen, and progesterone and strikingly, cell metabolism alteration in obesity participate in tumor development and progression, resistance to chemotherapy, and targeted therapies such as antiangiogenic and immune therapies.