Seed characteristics and fatty acid composition of castor (<i>Ricinus communis</i> L.) varieties in Northeast China

Oil content and fatty acid composition were investigated on 12 castor varieties and strains by using the soxhlet extraction method and capillary gas chromatography. This was made to provide a reference and theoretical basis for castorbean breeding with high oil content, determine variability of seed compounds for breeding purposes, and broaden chemical material choices. Results revealed that crude fat percentage in seeds ranged from 18.91 to 35.84% with an average of 25.91%; the absolute content of ricinoleic acid varied between 171.65 g/kg and 314.03 g/kg with an average of 222.43 g/kg, and kernel crude fat percentage was between 24.28 and 46.97% with an average of 34.30%. All these study variables were highest in the 2129 strain. The percentage of ricinoleic acid in crude fat was between 83.85 to 87.62%, and the highest value was found in the zhebi4 accession. The other fatty acids appeared in small concentrations, and showed small amplitude: 1.12 to 1.61%, 1.21 to 1.61%, 3.53 to 4.80%, 5.35 to 6.38%, 0.52 to 0.79%, 0.05 to 0.08% and 0.43 to 0.55%, for palmitic, stearic, oleic, linolic, linolenic, arachidic, and arachidonic acids, respectively. One hundred seed weight was determined for each accession. One hundred seed weight ranged from 25.7 g to 34.0 g with an average of 29.9 g. There was a significant correlation between seed weight and oil content, but the correlation value was low (r=0.51). Cluster analysis by SSPS based on the content of fatty acid composition revealed that the accessions were divided into three independent clusters. These findings will clearly provide useful information for further research in breeding and utilization of castor oil.     

Adaptive dynamics of cuticular hydrocarbons in Drosophila

Cuticular hydrocarbons (CHCs) are hydrophobic compounds deposited on the arthropod cuticle that are of functional significance with respect to stress tolerance, social interactions and mating dynamics. We characterized CHC profiles in natural populations of Drosophila melanogaster at five levels: across a latitudinal transect in the eastern United States, as a function of developmental temperature during culture, across seasonal time in replicate years, and as a function of rapid evolution in experimental mesocosms in the field. Furthermore, we also characterized spatial and temporal changes in allele frequencies for SNPs in genes that are associated with the production and chemical profile of CHCs. Our data demonstrate a striking degree of parallelism for clinal and seasonal variation in CHCs in this taxon; CHC profiles also demonstrate significant plasticity in response to rearing temperature, and the observed patterns of plasticity parallel the spatiotemporal patterns observed in nature. We find that these congruent shifts in CHC profiles across time and space are also mirrored by predictable shifts in allele frequencies at SNPs associated with CHC chain length. Finally, we observed rapid and predictable evolution of CHC profiles in experimental mesocosms in the field. Together, these data strongly suggest that CHC profiles respond rapidly and adaptively to environmental parameters that covary with latitude and season, and that this response reflects the process of local adaptation in natural populations of D. melanogaster.     

Genome, evolution, Drosophila and beyond: the new dimensions

A century ago a little fly with red eyes was first used for genetic studies. That insignificant fly, called at that time Drosophila ampelophila, revolutionized biology while becoming the model we know today under the name of Drosophila melanogaster. Since then its study has never ceased, but the field of interest has somewhat changed during the century. To caricature a little, today we essentially learn from Drosophila meetings that the fly has a brain! It is true that the fly is a tremendous model organism for neurobiology. But this fly is, in fact, an appropriate and recognized model for the whole of biology. Indeed, Drosophila meetings are exceptional opportunities to gather biologists of diverse backgrounds together. There we not only learn about the latest improvements in our field of interest, but surely appreciate learning another bit of biology. From this biological melting pot has emerged a culture very specific to the fly community. Thus besides neurobiology, cell biology and development, a diversity of other research fields exist; they all have their own place in the cultural and historical dimension of the "drosophila" model. Several communications from those diverse research fields were presented at the 8th Japanese Drosophila Research Conference (JDRC8) and are briefly covered here. We believe it more judicious to call the model "drosophila" without a capital initial, as the model has never really been limited to only the Drosophila genus. The vernacular name "drosophila" is currently used to designate any fly of the Drosophilidae family and we believe the term more appropriate than "small fruit fly" or "vinegar fly" to better include the species and ecological diversity of the model.     

Variations in body melanisation,ovariole number and fecundity in highland and lowland populations of Drosophila melanogaster from the Indian subcontinent

We investigated geographical variations in three fitness‐related traits (body melanisation, ovariole number and fecundity) in laboratory‐reared offspring of 10 populations of Drosophila melanogaster. The populations were collected from adjacent lowland and highland localities (～80–100 km apart) in the tropical as well as subtropical regions (11.15–31.06 °N) covering a linear distance about 3 000 kilometers from south to north on the Indian subcontinent. Persistence of within‐as well as between‐population differences at 21 °C suggest that observed variations in fitness‐related traits have a genetic basis. Populations from higher altitudes showed consistently higher trait values (1.4‐fold increase) as compared with their corresponding lowland populations. By contrast, latitudinal variations were about two‐fold higher across the entire continent. Along latitude as well as altitude, population means showed higher correlation values (r > 0.98) between all the three fitness traits. However, on the basis of within‐population analysis (assorted darker and lighter flies), changes in body melanisation were significantly correlated with fecundity but not with ovariole number. Thus, analysis of within‐population trait variability should be preferred as compared with data on population means for adaptive significance of fitness‐related traits. In the present study, the role of climatic selection is evident from regression analysis with changes in annual average temperature of the sites of origin of populations along latitude as well as altitude.     

Occurrence of oestrogenic pollutants and widespread feminisation of male tilapia in peri-urban dams in Bulawayo,Zimbabwe

Peri-urban water bodies are at risk from excessive pollution as they are direct sinks for urban effluents. The occurrence of oestrogenic and androgenic endocrine disrupting chemicals (EDCs) in effluents and water bodies around the city of Bulawayo, Zimbabwe, and their effects on wild fish was investigated in 2013. Effluent and water were sampled from sewage treatment plants, an urban stream, and effluent-polluted dams, and were compared with a ‘pristine’ dam upstream of Bulawayo. Organic pollutants were extracted by solid-phase extraction and tested for EDCs using a yeast oestrogen/androgen screen. Oestrogenic and androgenic potencies were expressed as 17β-oestradiol equivalent (EEq) or dihydrotestosterone equivalent (TEq). Tilapia and catfish from the dams were analysed for gonado-somatic indices and testis histopathology. Effluents from STPs, which directly flow into Umguza Dam, had EEq of 33 ng l^?1 and 55 ng l^?1, respectively. Umguza Dam, Khami Dam and Matsheumhlope Stream had EEqs of 237 ng l^–1, 9 ng l^?1 and 2 ng l^?1, respectively. Androgenic activity was detected in only one STP (TEq = 93 ng l^?1). Tilapia sampled from effluent-polluted dams had high incidences of testis-ova, but catfish had no signs of reproductive dysfunction. These findings underscore the need for greater attention to EDCs in developing countries where there is scant literature regarding their occurrence and impacts.     

Post‐eclosion temperature effects on insect cuticular hydrocarbon profiles

The insect cuticle is the interface between internal homeostasis and the often harsh external environment. Cuticular hydrocarbons (CHCs) are key constituents of this hard cuticle and are associated with a variety of functions including stress response and communication. CHC production and deposition on the insect cuticle vary among natural populations and are affected by developmental temperature; however, little is known about CHC plasticity in response to the environment experienced following eclosion, during which time the insect cuticle undergoes several crucial changes. We targeted this crucial to important phase and studied post‐eclosion temperature effects on CHC profiles in two natural populations of Drosophila melanogaster. A forty‐eight hour post‐eclosion exposure to three different temperatures (18, 25, and 30°C) significantly affected CHCs in both ancestral African and more recently derived North American populations of D. melanogaster. A clear shift from shorter to longer CHCs chain length was observed with increasing temperature, and the effects of post‐eclosion temperature varied across populations and between sexes. The quantitative differences in CHCs were associated with variation in desiccation tolerance among populations. Surprisingly, we did not detect any significant differences in water loss rate between African and North American populations. Overall, our results demonstrate strong genetic and plasticity effects in CHC profiles in response to environmental temperatures experienced at the adult stage as well as associations with desiccation tolerance, which is crucial in understanding holometabolan responses to stress.     

Extracellular phosphate ions cause apoptosis of terminally differentiated epiphyseal chondrocytes

Epiphyseal chondrocytes end their life cycle through apoptosis. While this event provides a mechanism for the removal of terminally differentiated cells from cartilage, agents that promote this physiological process have not been defined. To address this issue, using a cell culture technique that models events that take place in the growth plate, we asked the following questions: Can agents that promote chondrocyte maturation and cartilage mineralization serve as specific triggers for cell death? Are chondrocytes susceptible to apoptogens at a singular developmental stage? Treatment of embryonic tibial chondrocytes with inorganic phosphate (Pi) induced death in a dose- and time-dependent manner. Within 48 hr, 3 mM Pi increased chondrocyte death by 30%; lower concentrations of Pi induced death after 48 hr. To ascertain if death was due to apoptosis, we evaluated Pi-induced death by a number of different methods and compared the results to those induced by the apoptogen, staurosporine. Analysis of the death process indicated that cartilage cells shared many of the common biological features of the apoptotic process. Thus, there was DNA fragmentation, terminal deoxynucleotidyl transferase (TUNEL) labeling, an increase in cells in the sub-G1 fraction of the cell cycle, and morphological evidence of apoptosis. To explore the specificity of the Pi effect, the experiment was repeated using embryonic sternal cephalic and caudal chondrocytes, cells that are at an earlier developmental stage than the terminally differentiated tibial cells. We noted that these cells remained vital despite a major increase in the medium Pi content. Results of this study suggest that Pi is a stage-specific inducer of apoptosis in maturing chondrocytes and that this role may be linked to chondrocyte maturation and mineralization of the extracellular matrix.     

Pyrroloquinoline-quinone and its versatile roles in biological processes

Pyrroloquinoline-quinine (PQQ) was initially characterized as a redox cofactor for membrane-bound dehydrogenases in the bacterial system. Subsequently, PQQ was shown to be an antioxidant protecting the living cells from oxidative damage in vivo and the biomolecules from artificially produced reaction oxygen species in vitro. The presence of PQQ has been documented from different biological samples. It functions as a nutrient and vitamin for supporting the growth and protection of living cells under stress. Recently, the role of PQQ has also been shown as a bio-control agent for plant fungal pathogens, an inducer for proteins kinases involved in cellular differentiation of mammalian cells and as a redox sensor leading to development of biosensor. Recent reviews published on PQQ and enzymes requiring this cofactor have brought forth the case specific roles of PQQ. This review covers the comprehensive information on various aspects of PQQ known till date. These include the roles of PQQ in the regulation of cellular growth and differentiation in mammalian system, as a nutrient and vitamin in stress tolerance, in crop productivity through increasing the availability of insoluble phosphate and as a bio-control agent, and as a redox agent leading to the biosensor development. Most recent findings correlating the exceptionally high redox recycling ability of PQQ to its potential as anti-neurodegenerative, anticancer and pharmacological agents, and as a signalling molecule have been distinctly brought out. This review discusses different findings suggesting the versatility in PQQ functions and provides the most plausible intellectual basis to the ubiquitous roles of this compound in a large number of biological processes, as a nutrient and a perspective vitamin.     

Organization of fusicoccin receptor in higher plant plasma membrane: relationship between affinity and molecular mass

Higher plant plasma membranes carry receptors of different affinity for the phytotoxin fusicoccin. Reception of fusicoccin involves proteins belonging to the highly conserved 14-3-3 family, but the complete structure of the fusicoccin receptor (FCR) is unknown. Using radiation inactivation analysis, we estimated the molecular masses of low-affinity and high-affinity FCR at 63 +/- 7 and 130 +/- 15 kD, respectively. The dose dependences of receptor inactivation indicate that microsomal specimens contain "silent" FCRs of 420 +/- 90 kD in amounts commensurate with that of the active FCRs. Both low- and high-affinity FCRs are inactivated by hydrolytic enzymes from the outer surface of the plasma membrane, and impairment of protoplast integrity causes an irreversible transition of the low-affinity binding site into the high-affinity one. A scheme is proposed for the organization of different types of FCR in the plasma membrane, implying that the membrane affinity for fusicoccin reflects the interaction between proteins in the FCR complex.