Production and evolution pattern of “fruity smell” aggregation pheromones in genus Drosophila

Insects produce pheromones to serve a range of ecological functions throughout their lifetime. The chemical composition, production pattern, and interspecies specificity provide information for carrying out their function and biological significance. Several species of Drosophila produce a class of volatile esters considered as “fruity smells”; however, the production pattern and ecological functions of these “fruity smell” volatiles in genus Drosophila are poorly understood. Here, using the headspace solid-phase microextraction (SPME) method, we tested the production pattern of volatile pheromones in Drosophila immigrans and factors that possibly affected pheromone production, including mating, feeding conditions, age of adult flies, and geographical distribution. We also explored the evolution and production pattern of volatile pheromones in 14 species of genus Drosophila. Our result showed that male D. immigrans adult flies produce three male-specific volatile ester pheromones, which are also considered as “fruity smell” chemicals, in a relatively stable pattern. In addition, a series of “fruity smell” ester pheromones with similar structure and chemical properties were found to appear in the species of D. virilis and D. immigrans species group, but not in the species of D. melanogaster species group. The ester volatile pheromone production of male flies has a correspondence with the female's demand for host plants. Integrating the production and evolution pattern of these volatile chemicals, we inferred the interaction between insects and host plants reflected in the Drosophila “fruity smell” pheromones.     

Visualization and solubilization of rat brain opiate receptors with a “κ” ligand selectivity pattern

1. Specific binding of [3H]ethylketocyclazocine (EkappaC), a prototype kappa-opiate agonist, to slide-mounted rat striatal sections is increased in the presence of 100 mM NaCl at 4 degrees C. 2. Under similar incubation conditions, binding of mu and delta prototype opiates is reduced to almost undetectable levels. 3. Correlation (P less than 0.01) of the ligand selectivity pattern of [3H]EKC displacement with the potencies of various opiate drugs in inhibiting the contractions of the rabbit vas deferens, a kappa-opiate receptor bioassay, suggests that the binding site under study represents the pharmacologically relevant kappa-opiate receptor. 4. Visualization of these kappa-opiate receptors with tritium-sensitive film reveals a striking, highly discrete brain distribution pattern (e.g., striatal patches, habenular stripe) which is similar to that of [3H]dihydromorphine and [3H]naloxone. 5. Soluble [3H]EKC binding sites obtained from rat membranes also possess a kappa-like ligand selectivity pattern, with bremazocine being a potent displacer while mu and delta ligands are almost inactive. 6. A possible explanation of these data is that the "kappa"-opiate binding site in rat brain is one transitional state of an opiate receptor capable of assuming distinct conformations with characteristic ligand selectivity patterns. Other possibilities such as pre and post-synaptic locations should also be considered.     

Utilization of nitrate abolishes the “Custers effect” in Dekkera bruxellensis and determines a different pattern of fermentation products

Nitrate is one of the most abundant nitrogen sources in nature. Several yeast species have been shown to be able to assimilate nitrate and nitrite, but the metabolic pathway has been studied in very few of them. Dekkera bruxellensis can use nitrate as sole nitrogen source and this metabolic characteristic can render D. bruxellensis able to overcome S. cerevisiae populations in industrial bioethanol fermentations. In order to better characterize how nitrate utilization affects carbon metabolism and the yields of the fermentation products, we investigated this trait in defined media under well-controlled aerobic and anaerobic conditions. Our experiments showed that in D. bruxellensis, utilization of nitrate determines a different pattern of fermentation products. Acetic acid, instead of ethanol, became in fact the main product of glucose metabolism under aerobic conditions. We have also demonstrated that under anaerobic conditions, nitrate assimilation abolishes the “Custers effect”, in this way improving its fermentative metabolism. This can offer a new strategy, besides aeration, to sustain growth and ethanol production for the employment of this yeast in industrial processes.     

Cell type-specific and site directed N-glycosylation pattern of FcγRIIIa

Human leukocyte receptor IIIa (hFcγRIIIa) plays a prominent role in the elimination of tumor cells by antibody-based cancer therapies. In previous studies, a major impact of the presence of carbohydrates at Asn-162 on the binding between the receptor and the Fc part of wild type fucosylated or glycoengineered nonfucosylated antibodies has been shown. In this study, we performed a site directed carbohydrate analysis at hFcγRIIIa derived from human embryonic kidney (HEK) and Chinese hamster ovary (CHO) cells, respectively. Using mass spectrometry (MS) and a multienzyme protein digest, we analyzed the proteolysis-generated glycopeptides in detail. We could show that hFcγRIIIa expressed by HEK cells was mostly bearing multifucosylated biantennary Asn162-glycans with a major fraction terminating with GalNAc residues replacing the more common Gal. We could demonstrate that the glycan antennae with terminal GalNAc could be sialylated as indicated by a novel reporter ion HexNAcHexNAcNeuAc(+) (m/z 698.28) using a source induced dissociation (SID) scan in the MS cycle. In contrast to the hFcγRIIIa Asn-162 glycosylation pattern from HEK cells, the CHO cells derived receptor contains bi- and triantennary galactosylated and highly sialylated carbohydrates. Our data suggest that the type of expression host system was a dominating factor for formation of distinct glycopatterns of hFcγRIIIa, while the protein sequence and the site of glycosylation remained unchanged for both types of cells. Using surface plasmon resonance (SPR) interaction analysis, we show that the cell type and site specific glycosylation pattern of hFcγRIIIa influences its binding behavior to immunoglobulin molecules.     

How does pattern of feeding and rate of nutrient delivery influence conditioned food preferences?

Ruminant herbivores have been shown to learn about food properties by associating food flavours with the food’s post-ingestive consequences. Previous experimentation supporting the conditioned food aversion/preference hypothesis has generally employed very simple diet learning tasks which do not effectively represent the wide range of foods selected within single bouts typical of wild, free-ranging ruminant herbivores. We tested the ability of a ruminant herbivore to associate a food with artificially administered nutrient rewards in a designed experiment where we altered the temporal pattern of encounter with the food as well as the nature (fast or slow reward) of the post-ingestive outcome. Twenty-four goats were offered branches of Sitka spruce (SS) and Norway spruce (NS) for 4 h per day on two days per week for five weeks. The pattern of feeding varied with treatment such that the species on offer changed every hour (short) or every 2 h (long). The energy treatment altered the reward delivered during Sitka consumption so that animals were dosed either with predominantly sugar (rapidly fermented), predominantly starch (slower fermentation rate), or with water (placebo). Preference was measured on the day following each learning day. We expected that goats would find it easier to associate SS with post-ingestive rewards when the duration of encounter was longest, and that associations would be stronger with the most rapidly digested post-ingestive reward. In the event, goats did not alter their consumption of SS in response to the treatments. Our results suggest that at the scale of temporal resolution of encounters with different plant species (1–2 h), and at the different rates of experiencing post-ingestive consequences tested in this experiment, ruminants do not appear to discriminate the nutritive properties of foods predominantly through a post-ingestive feedback mechanism. They must, instead, use a range of cues—including post-ingestive consequences—to assess food properties. An erratum to this article can be found at     

Molecular cloning of α-amanitin and characterization of its expression pattern in different parts and development stages of Amanita exitialis fruitbody

Amanita exitialis is a lethal mushroom in East Asia. α-Amanitin is one kind of the leading peptide toxins responsible for mushroom poisoning, which are mainly from the fatal amanitae. In the study, the full-length cDNA sequences of α-amanitin (α-AMA) and phallacidin (PHA) from A. exitialis were cloned and analyzed; in addition, the expression patterns of α-AMA in three parts as well as four developmental stages of the fruitbody were first characterized by quantitative real-time PCR. Results demonstrate that α-AMA and PHA were highly homologous to the toxin genes reported from A. bisporigera; the α-AMA could be expressed in all parts and stages of the fruitbody, from late elongation stage to late mature stage, α-AMA showed the highest expression level in the pileus, followed by the stipe and volva in sequence, while at the early elongation stage, the highest expression level was found in the stipe, followed by the pileus and volva. Further analysis revealed that the higher expression level of α-AMA was closely associated with the development stages, and the expression of α-AMA was accumulated in the more vigorous growth parts and stages, from which could be inferred that α-AMA might play an important role in the development of A. exitialis.     

REVIEW: Is the “flagellate” pattern of spermatogenesis plesiomorphic in Metazoa?

Summary

The phenomenon of “flagellate spermatogenesis” typically known among marine invertebrates with “primitive” sperm and external or external-internal fertilization is discussed. It is suggested that “flagella bearing” in early germinative cells might be explained by plesiomorphic similarity between these cells and flagellate somatic epithelial cells. The early germ cells of more apomorphic multicellular animals using internal fertilization with “modified” and “aberrant” sperm typically have no flagella and this organelle, as the sperm tail, first appears in spermatids. It is speculated that the “flagellate” pattern typifies the basal level and that the transition between “flagellate” and “specialized” spermatogenesis constitutes a significant step in evolution.     

The α-amylase of the beetle Callosobruchus chinensis. Purification and action pattern

Callosobruchus chinensis larval amylase was isolated and purified in five steps, which included co-precipitation with glycogen and column chromatography on ECTEOLA-cellulose. The enzyme was homogeneous by disc gel electrophoresis on polyacrylamide. The alpha-amylase nature was evidenced by the action on amylopectin beta-amylase limit-dextrin, by the effect on the substrate-iodine complex and by the action pattern on several polysaccharide substrates. These action patterns are compared with those of other alpha-amylases.     

Comparative freezing patterns of bark and xylem of “Siberian C” and “Redhaven” peach twigs

An electrophoretic mobility technique was used to study freezing patterns in excised peach twigs. Moisture content was the only qualitative difference in initial freezing patterns of similar tissues of Redhaven and Siberian C. Siberian C contained up to 18% less moisture than Redhaven. Major differences in the shape of the transition pattern were detected between bark and xylem. Even though bark tissues had twice the water content of xylem, the bark exhibited equilibrium freezing while the xylem underwent nonequilibrium freezing. Bark water must be intimately associated with the living protoplast, while xylem water is less closely associated with cellular components. Comparison of bark and xylem freezing curves with sucrose and cellulose model systems suggested that bark freezing was similar to the sucrose model while xylem freezing was similar to the cellulose model.     

The spatial pattern and dispersion of Lygodium microphyllum in the Everglades wetland ecosystem

Since 1958, L. microphyllum (Old World Climbing Fern), which originated from the Old World Tropics, has become a nuisance exotic and has rapidly spread and is being established system-wide in extremely remote and undisturbed areas such as the Florida Everglades. Of particular concern is that L. microphyllum is disrupting, at an alarming rate, the flora and fauna of the native ecosystem at the same time that a major 8.4 billion dollar Everglades restoration program is trying to enhance these same attributes. This research utilized IKONOS satellite data to map L. microphyllum within the 58,000-ha Loxahatchee National Wildlife Refuge wetland in south Florida. Results show that approximately 11.6% of the tree/shrub vegetation within the impoundment has been infected by L. microphyllum. These data were then utilized to explore the spatial spread patterns of L. microphyllum within the Refuge. Results suggest that L. microphyllum is more likely to establish on the southeast side of a tree/shrub island and then spread to the northwest, which corresponds to the prevailing wind direction in south Florida. Spatial pattern analysis of L. microphyllum spread indicated that it is correlated with the density and spatial distribution of tree/shrub island vegetation. It appears that the dispersion of L. microphyllum is density dependent, which can be expressed as a logistic function and has a catastrophic threshold of 160 m of mean distance between tree/shrub islands in the Everglades. It is predicted that 38% (or 1910 ha) of tree/shrub islands in the Refuge will be invaded by L. microphyllum by 2012. Tree islands in the Everglades wetland could be considered similar to oceanic islands throughout the world that are notoriously vulnerable to biological invasions.     

Do food protein and carbohydrate content influence the pattern of feeding and the tendency to explore of forest tent caterpillars?

This study examines whether the ratio of protein to carbohydrate affects the timing of meals and the propensity to explore of forest tent caterpillars (Malacosoma disstria). The behavior of fourth instar caterpillars was observed on three semi-defined artificial diets varying in protein (p)-carbohydrate (c) ratio. These diets were (a) p14:c28, (b) p28:c14, and (c) p35:c7. The probability of initiating feeding at first contact with the food and the duration of the first feeding event did not vary across diets, suggesting not much difference in phagostimulatory power. There was also no difference in the total time spent eating, at rest and in motion between diets. However, the timing and duration of meals varied significantly; more short meals were observed on the carbohydrate-biased diet. The duration of pauses between meals also increased with food protein content. Furthermore, caterpillars on the carbohydrate-biased diet were more likely to leave the trail leading to the known food source and to discover a second food source, suggesting that protein deprivation promotes exploration. These findings shed insight into the physiological responses to protein and carbohydrate ingestion and demonstrate how post-ingestive effects can favor consumption of foods containing protein without invoking an explicit mechanism of independent nutrient regulation, but simply by influencing the pattern of feeding and the propensity to explore.     

Expression pattern of estrogen receptors α and β and G-protein-coupled estrogen receptor 1 in the human testis

Estrogen signaling is considered to play an important role in spermatogenesis, spermiogenesis and male fertility. Estrogens can act via the two nuclear estrogen receptors ESR1 (ERα) and ESR2 (ERβ) or via the intracellular G-protein-coupled estrogen receptor 1 (GPER, formerly GPR30). Several reports on the localization and expression of all three receptors in the human testis have been published but are controversial particularly in case of ERα. Contrary to previous studies, we decided therefore to evaluate expression of all three receptors in the testis by a number of different methods and in comparison with MCF-7 cells. Using qPCR, we could show that mRNA expression of ERα is considerably lower and expression of ERβ and GPER much higher in the testis than in MCF-7 cells. RT-PCR after laser-assisted microdissection of tubular and interstitial compartments from normal and Sertoli cell only syndrome testes plus in situ hybridization and immunohistochemical analyses of the same samples demonstrated that there is very low expression of ERα in germ cells and in single interstitial cells, very high expression of ERβ in germ cells and Sertoli cells and high expression of GPER in interstitial cells and less in Sertoli cells.     

Molecular basis and evolutionary pattern of GA–GID1–DELLA regulatory module

The tetracyclic diterpenoid carboxylic acids, gibberellins (GAs), orchestrate a broad spectrum of biological programs. In nature, GAs or GA-like substance is produced in bacteria, fungi, and plants. The function of GAs in microorganisms remains largely unknown. Phytohormones GAs mediate diverse growth and developmental processes through the life cycle of plants. The GA biosynthetic and metabolic pathways in bacteria, fungi, and plants are remarkably divergent. In vascular plants, phytohormone GA, receptor GID1, and repressor DELLA shape the GA–GID1–DELLA module in GA signaling cascade. Sequence reshuffling, functional divergence, and adaptive selection are main driving forces during the evolution of GA pathway components. The GA–GID1–DELLA complex interacts with second messengers and other plant hormones to integrate environmental and endogenous cues, which is beneficial to phytohormones homeostasis and other biological events. In this review, we first briefly describe GA metabolism pathway, signaling perception, and its second messengers. Then, we examine the evolution of GA pathway genes. Finally, we focus on reviewing the crosstalk between GA–GID1–DELLA module and phytohormones. Deciphering mechanisms underlying plant hormonal interactions are not only beneficial to addressing basic biological questions, but also have practical implications for developing crops with ideotypes to meet the future demand.     

What's in a band? The function of the color and banding pattern of the Banded Swallowtail

Butterflies have evolved a diversity of color patterns, but the ecological functions for most of these patterns are still poorly understood. The Banded Swallowtail butterfly, Papilio demolion demolion, is a mostly black butterfly with a greenish‐blue band that traverses the wings. The function of this wing pattern remains unknown. Here, we examined the morphology of black and green‐blue colored scales, and how the color and banding pattern affects predation risk in the wild. The protective benefits of the transversal band and of its green‐blue color were tested via the use of paper model replicas of the Banded Swallowtail with variations in band shape and band color in a full factorial design. A variant model where the continuous transversal green‐blue band was shifted and made discontinuous tested the protective benefit of the transversal band, while grayscale variants of the wildtype and distorted band models assessed the protective benefit of the green‐blue color. Paper models of the variants and the wildtype were placed simultaneously in the field with live baits. Wildtype models were the least preyed upon compared with all other variants, while gray models with distorted bands suffered the greatest predation. The color and the continuous band of the Banded Swallowtail hence confer antipredator qualities. We propose that the shape of the band hinders detection of the butterfly's true shape through coincident disruptive coloration; while the green color of the band prevents detection of the butterfly from its background via differential blending. Differential blending is aided by the green‐blue color being due to pigments rather than via structural coloration. Both green and black scales have identical structures, and the scales follow the Bauplan of pigmented scales documented in other Papilio butterflies.     

Molecular evolution and expression pattern of Toll-like receptor 3 from the lamprey Lampetra japonica

Toll-like receptors(TLRs)are type I transmembrane proteins that are important components of innate immunity and play essential roles in inducing acquired immune responses[1].These proteins consist of three parts:the cytoplasmic domain,transmembrane domain,and extracellular domain.The extracellular domain is composed of 18–33 leucine-rich repeat(LRR)sequences that enable the host to specifically recognize pathogen-associated molecular patterns and are the core of TLR recognition ligands[2].The cytoplasmic domain is homologous with the interleukin 1 receptor(IL-1R)family and known as the Toll-IL-1 receptor homology domain,which is highly conserved and plays a key role in signal transduction[1].TLR3 recognizes viral dsRNA during immune protection from viruses[3].After the host is infected by a virus,the LRR region of TLR3 recognizes the viral dsRNA,and the Toll/IL-1 receptor(TIR)domain recruits the adaptor protein TIR domain-containing molecule 1(also known as TRIF)for signal cascade transmission[4].The activation of TLR3 finally leads to cytokine secretion,especially the production of type I interferon[4].Lamprey,the most primitive marine jawless vertebrate,is an ideal model for studying vertebrate embryo development,organ differentiation,and immune system evolution[5].Although jawless vertebrates contain three variable lymphocyte receptors,they have not been found to possess the recombinational antigen receptors shared by all jawed vertebrates[6].Compared with that in higher vertebrates,the mechanism of acquired immunity in lampreys is still not complete,and lampreys rely mainly on innate immunity to fight against pathogenic microorganisms.Although TLR3 has been extensively studied in jawed vertebrates,little is known about the molecular evolutionary history and expression patterns of TLR3 in jawless vertebrates.     

Population sizes and dispersal pattern of tsetse flies: rolling on the river?

The West African trypanosomoses are mostly transmitted by riverine species of tsetse fly. In this study, we estimate the dispersal and population size of tsetse populations located along the Mouhoun river in Burkina Faso where tsetse habitats are experiencing increasing fragmentation caused by human encroachment. Dispersal estimated through direct (mark and recapture) and indirect (genetic isolation by distance) methods appeared consistent with one another. In these fragmented landscapes, tsetse flies displayed localized, small subpopulations with relatively short effective dispersal. We discuss how such information is crucial for designing optimal strategies for eliminating this threat. To estimate ecological parameters of wild animal populations, the genetic measures are both a cost- and time-effective alternative to mark–release–recapture. They can be applied to other vector-borne diseases of medical and/or economic importance.     

Synthesis of “Reversed” and “Double Headed” Nucleosides

Abstract

The synthesis of several partially and fully deprotected “reversed” nucleosides are described starting from “reversed” 5-iodouracil-1-yl nucleoside 1. The preparation of a novel purine-purine and mixed purine-pyrimidine “double headed” nucleosides via “reversed” purine nucleoside 12 is also described.     

Effect of cortisone on the developmental pattern of the neutral and the acid β-galactosidases of the small intestine of the rat

1. The developmental pattern and effect of cortisone on acid beta-galactosidase and neutral beta-galactosidase were studied in postnatal rats by a recently proposed method for their independent determination. 2. After birth the acid beta-galactosidase activity increases in the ileum, whereas it decreases slightly in the jejunum. On day 16 after birth the activity in the ileum decreases and in 20-day-old rats activity in both parts of the intestine decreases to adult values. In suckling animals the activity in the ileum exceeds the jejunal activity severalfold and in adult animals the activity in the jejunum is slightly higher than that in the ileum. 3. Neutral beta-galactosidase activity is high after birth and decreases in both jejunum and ileum after day 20 after birth. In 12-20-day-old rats activity in both parts is essentially the same, but in adult animals jejunal activity exceeds ileal activity four-to five-fold. 4. Cortisone (0.5, 2.0 or 5.0mg/100g body wt. daily for 4 days) does not influence the activity of either enzyme in 60-day-old rats. Acid beta-galactosidase activity is decreased after cortisone treatment in 8-, 12-, 16-and 18-day-old rats, with sensitivity to cortisone increasing with the approach of weaning. No effect of cortisone on acid beta-galactosidase is seen in 8-day-old rats. Neutral beta-galactosidase activity is increased in the ileum of 8-, 12-, 16- and 18-day old rats, but only in the jejunum of 8-and 12-day-old rats.