Genetic diversity patterns in Curcuma reflect differences in genome size

The relationships between genome size and the systematic and evolutionary patterns in vascular plants are equivocal, although a close relationship between genome size and evolutionary patterns has been previously reported. However, several studies have also revealed the dynamic nature of genome size evolution and its considerable ‘ups’ and ‘downs’. Thus, in this study, the phylogenetic relationships among three previously revealed genome size groups and among species of the highly polyploid genus Curcuma were evaluated using AFLP. Our results suggest two main lineages within Indian Curcuma reflecting evolution of genome size. The first one includes hexaploids and higher polyploids of the previously recognized genome size group I, and the second one includes mainly hexaploids of genome size groups II and III. Within genome size group I, relationships among species seem to be influenced by reticulate evolution and higher polyploids are likely to be of allopolyploid origin. Reproductive systems in Indian Curcuma vary considerably among ploidy levels and these differences considerably affect morphological and genetic variation. In general, clonally reproducing species are expected to exhibit low genotypic diversity, but, at the same time, species of allopolyploid origin are expected to maintain higher levels of heterozygosity compared with their progenitors. We investigated intra‐populational genetic variability in Curcuma spp. to evaluate whether mode of reproduction or ploidy represent the main factor influencing the degree of genetic diversity. We found that hexaploid species exhibited significantly higher genetic diversity than higher polyploids (9x, 15x). Our results suggest that this genetic diversity pattern is largely influenced by the mode of reproduction, as higher polyploids reproduce exclusively vegetatively, whereas hexaploids reproduce mainly sexually. © 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2011, 165 , 388–401.     

Use of frozen bagged seed inoculum for secondary metabolite and bioconversion processes at the pilot scale

Frozen bagged seed inoculum was prepared, thawed and tested for seven cultures. Thawing techniques were developed and other key influences on thawing rate were quantified; seed bag thawing without a water bath rarely required more than 4 to 5 h and was as short as 0.5 to 1 h for lower fill volume bags. Testing included growth of bagged seed as a function of bag fill volume (0.5, 1.0, 2.0, and 3.5 L), comparison of culture age at time of bagging, growth of bagged versus laboratory-prepared seed, productivity of production cultures derived from bagged versus laboratory-prepared seed, growth of bagged seed as a function of volume percent glycerol added at time of bagging, and growth of bagged seed as a function of frozen storage time and temperature. For each culture tested, conditions were developed such that seed tanks inoculated with bagged seed showed only minimal delay in attaining the target oxygen uptake rate (OUR) relative to seed tanks inoculated with laboratory-prepared inoculum. Although the bag fill volume did influence culture growth in some cases, bag fill volumes required were reasonable (typically 2.0 to 3.5 L) compared with laboratory seed inoculum volumes of 2.0 L. In the most remarkable example, frozen bagged seed was prepared from a second-stage seed-tank cultivation of Glarca lozoyensis, then thawed and inoculated into first-stage seed medium. It grew to the desired OUR in a similar timeframe as laboratory-prepared inoculum inoculated into first-stage seed medium. Thus, the frozen bagged seed replaced an existing laboratory inoculum preparation period of 7 days without an appreciable delay in either of the two subsequent seed-tank growth stages. Furthermore, productivities were found to be comparable for bagged-seed-derived and laboratory-seed-derived production cultivations for four different fermentation processes.     

Immune deficiency in the X-linked lymphoproliferative syndrome. II. Immunoregulatory T cell defects

Surface phenotypic markers and the function of lymphocytes in patients affected with the X-linked lymphoproliferative syndrome (XLP) were studied. This syndrome is characterized by a defective response to infection with Epstein Barr virus (EBV). Normal numbers of B and T cells were detected with anti-Ig and monoclonal OKT3 antisera, respectively. T cell subset values, however, were persistently altered: cells reacting with OKT8 were significantly elevated in five of nine patients, accompanied by a slight decrease in the percentage of OKT4-positive cells, leading to abnormally low OKT4 to OKT8 ratios. One patient had a high OKT4 to OKT8 ratio due to low number of OKT8-positive cells. Lymphocytes from patients showed normal proliferation after stimulation with T and B cell mitogens. In contrast, Ig synthesis by lymphocytes after stimulation with B cell mitogens was markedly deficient: low or undetectable levels of one or all classes of Ig were detected, whereas cell lines established from EBV-infected B lymphocytes from patients produced normal quantities of Ig. These studies imply immune regulatory impairments in the patient with XLP.     

Higher Quality of Life and Lower Depression for People on ART in Uganda as Compared to a Community Control Group

Provision of antiretroviral treatment (ART) to people living with HIV (PLWH) has increased globally. Research measuring whether ART restores subjective well-being to “normal” levels is lacking, particularly in resource limited settings. The study objectives are to compare quality of life and depression symptoms for PLWH on ART to a general community population and to explore factors to explain these differences, including socio-economic status and the impact of urban or rural residence. PLWH on ART (n = 263) were recruited from ART delivery sites and participants not on ART (n = 160) were recruited from communities in Wakiso District, Uganda. Participants were interviewed using the translated World Health Organisation Quality of Life brief measure, the Hopkins Symptom Checklist depression section, and questions about socio-economic status, residence as urban or rural and, for PLWH on ART, self-reported adherence and use of HIV counselling. Compared to the community sample and controlling for location of residence, PLWH on ART had significantly higher quality of life (QOL) for physical, psychological and environment domains, but not the social domain. These differences were not due to socio-economic status alone. Depression scores were significantly lower for PLWH on ART. Both comparisons controlled for the effect of location of residence. People on ART self-reported high adherence and the majority had used HIV counselling services. Our findings show better QOL amongst PLWH on ART compared to a general community sample, which cannot be explained solely by differences in socio-economic status nor location of residence. The general community sample results point towards the challenges of life in this setting. Access to health services may underpin this difference and further research should explore this finding, in addition to identification of psychological mechanisms that relate to better QOL. ART provision infrastructure has clear benefits. Further work should consider sustainability and replication for other health conditions.     

Long-term orexigenic effects of AgRP-(83---132) involve mechanisms other than melanocortin receptor blockade

Overexpression of agouti-related peptide (AgRP), an endogenous melanocortin (MC) 3 and 4 receptor antagonist (MC3/4-R), causes obesity. Exogenous AgRP-(83---132) increases food intake, but its duration and mode of action are unknown. We report herein that doses as low as 10 pmol can have a potent effect on food intake of rats over a 24-h period after intracerebroventricular injection. Additionally, a single third ventricular dose as low as 100 pmol in rats produces a robust increase in food intake that persists for an entire week. AgRP-(83---132) completely blocks the anorectic effect of MTII (MC3/4-R agonist), given simultaneously, consistent with a competitive antagonist action. However, when given 24 h prior to MTII, AgRP-(83---132) is ineffective at reversing the anorectic effects of the agonist. These results support a critical role of MC tone in limiting food intake and indicate that the orexigenic effects of AgRP-(83---132) are initially mediated by competitive antagonism at MC receptors but are sustained by alternate mechanisms.     

Neuropeptide Y prepares rats for scheduled feeding

When neuropeptide Y (NPY) is administered centrally, meal-anticipatory responses are elicited. If an increase of endogenous NPY is a signal that heralds an imminent large caloric load, timed daily NPY injections may be expected to condition meal-anticipatory responses that facilitate ingestion. Rats received 4-h access to food beginning in the morning and then timed (1600 h), daily third-ventricular injections of NPY or saline for 7 days. On test day (day 8), animals received the conditioning drug (NPY or saline) or the opposite drug. Food was available immediately after injection on test day, and intake was measured. Rats conditioned with NPY and then given saline ate significantly more than rats conditioned with saline and then given saline; they ate the same amount as rats given NPY. Although they ate more, rats trained with NPY did not have changed plasma glucose, insulin, or ghrelin. These data suggest that NPY plays a role in mediating conditionable food-anticipatory responses that help to cope with the effects of large caloric loads.     

When is self-organization used in biological systems?

Self-organization, or decentralized control, is widespread in biological systems, including cells, organisms, and groups. It is not, however, the universal means of organization. I argue that a biological system will be self-organized when it possesses a large number of subunits, and these subunits lack either the communicational abilities or the computational abilities, or both, that are needed to implement centralized control. Such control requires a well informed and highly intelligent supervisor. I stress that the subunits in a self-organized system do not necessarily have low cognitive abilities. A lack of preadaptations for evolving a system-wide communication network can prevent the evolution of centralized control. Hence, sometimes even systems whose subunits possess high cognitive abilities will be self-organized.