Epigenetic and molecular signatures of cord blood CD34(+) cells treated with histone deacetylase inhibitors.

BACKGROUND AND OBJECTIVES: Epigenetic modifications tightly regulate the gene expression and cellular function of haematopoietic stem cells. Histone deacetylase inhibitors (HDACIs) alter the gene expression profile of cord blood (CB) CD34(+) cells by controlling the genes involved in chromatin modification, thereby influencing the self-renewal, maintenance and expansion of haematopoietic stem and progenitor cells (HSPCs). MATERIALS AND METHODS: The class I and II HDACIs, valproic acid and scriptaid, were utilized to expand CB-CD34(+) cells ex vivo. The gene profiling was performed on HSPC using Illumina microarray, GeneGO MetaCore(™) and Ingenuity pathway analyses. The molecular analyses were performed using Q-PCR and Western blotting. RESULTS: Each HDACI treatment of CB-CD34(+) cells created unique epigenetic and molecular signatures that governed chromatin modification required for cellular and functional behaviour of stem cells. GeneGO MetaCore(™) and Ingenuity pathway analyses established the molecular understanding of epigenetically regulated HSPCs in the presence of scriptaid and VPA that revealed different network(s) of potential regulators during erythropoiesis. VPA induced transcriptional activation of the glucocorticoid receptor (GCR) and an increase in the intracellular signalling of signal transducers and activators of transcription (STAT) required during stress erythropoiesis. Canonical Wnt signalling and many epigenetically regulated chromatin remodellers were significantly influenced so as to establish maintenance and regulation of HSPC. CONCLUSION: Treatment with Individual HDACIs has demonstrated significantly unique epigenetic and molecular signatures of CB-HSPC. This study identifies potential key regulators of HSPC and gives insights into the clinically important processes of HSPC expansion and haematopoietic lineage development for transplantation purposes.

Huizache (Acacia farnesiana) whole pods (flesh and seeds) as an alternative feed for sheep in Mexico.

Two experiments were undertaken to evaluate the use of pods from Huizache (Acacia farnesiana), common in the arid and semiarid regions of Mexico, on the perfromance and apparent digestibility in Pelibuey Mexican hair growing ewe lambs. Twenty-four Pelibuey ewe lambs were used in the animal performance experiment, with a mean live weight of 14.91 +/- 1.48 kg, randomnly allocated to three groups which received ad libitum for 77 days (11 weeks) experimental whole rations T0 with 0%, T12 with 12% or T24 with 24% inclusión of dried and ground Huizache pods. Dry matter intakes (g/kg (0.75) daily) were 83, 95, 90 for T0, T12, and T24 respectively (P > 0.05). Mean daily live-weight gain was 90, 75, and 63 g/day for T0, T12, and T24 (P < 0.001). Nine Pelibuey ewe lambs were used to determine apparent digestibility in vivo of the experimental diets using a 3 x 3 latin square design repeated three times. There were differences in the digestibility of dry matter (P < 0.001), organic matter (P < 0.001), nitrogen (P < 0.031), neutral detergent fibre (P < 0.002), and acid detergent fibre (P < 0.001) being lower in T24. Huizache pods may be an alternative feed when included up to 12% of dry matter in the diets for sheep growing moderately.

The role of large-scale spatially explicit and small-scale localized processes on the population dynamics of cereal aphids.

A field-scale study of the spatially explicit interaction between the carabid Poecilus cupreus Linnaeus, and two common aphid species (Sitobion avenae (Fabricius) and Metopolophium dirhodum (Walker)) in winter wheat was conducted. All three species showed considerable spatial pattern at the field scale. Activity-density of P. cupreus was an order of magnitude higher in the central part of the field compared to its periphery. Where P. cupreus activity-density was highest, S. avenae and M. dirhodum population peaks were delayed. Additionally, in the case of M. dirhodum, lower maximum counts were evident where P. cupreus activity-density was highest. An analysis of the movement of individual P. cupreus using release-recapture indicated that those beetles within the centre of the field exhibited reduced displacement, which may have caused the generation or maintenance of spatial pattern. Crop density was also measured throughout the field. Although crop density had no large-scale spatial pattern, its variability at the small-scale was consistent with an influence on aphid population dynamics. This study demonstrates empirically that both large-scale spatially explicit and small-scale localized processes influenced aphid population dynamics simultaneously.

Microsatellites and 16S sequences corroborate phenotypic evidence of trans-Andean variation in the parasitoid Microctonus hyperodae (Hymenoptera: Braconidae).

Eight South American geographical populations of the parasitoid Microctonus hyperodae Loan were collected in South America (Argentina, Brazil, Chile and Uruguay) and released in New Zealand for biological control of the weevil Listronotus bonariensis (Kuschel), a pest of pasture grasses and cereals. DNA sequencing (16S, COI, 28S, ITS1, beta-tubulin), RAPD, AFLP, microsatellite, SSCP and RFLP analyses were used to seek markers for discriminating between the South American populations. All of the South American populations were more homogeneous than expected. However, variation in microsatellites and 16S gene sequences corroborated morphological, allozyme and other phenotypic evidence of trans-Andes variation between the populations. The Chilean populations were the most genetically variable, while the variation present on the eastern side of the Andes mountains was a subset of that observed in Chile.

The spatial dynamics of crop and ground active predatory arthropods and their aphid prey in winter wheat.

The distribution of aphid predators within arable fields has been previously examined using pitfall traps. With this technique predominantly larger invertebrate species are captured, especially Carabidae, but the technique provides no estimate of density unless mark-recapture is used. However, many other numerically important aphid predators occur in arable fields and relatively little is known about their distribution patterns nor whether they exhibit a density-dependent response to patches of cereal aphids. Identification of the most effective predators can allow management practices to be developed accordingly. In this study, the distribution of cereal aphids and their predators was examined by suction sampling within a field of winter wheat in Devon, UK, along with visual estimates of weed patchiness. Sampling was conducted on four occasions in 1999 across a grid of 128 sample locations. The distribution of 11 predatory taxa from the Carabidae, Staphylinidae and Linyphiidae was examined. Additionally, the total number of aphid predators and a predation index were used in these analyses. Carabid adults and larvae, along with staphylinid larvae showed the strongest aggregation into patches and the most temporal stability in their distribution. Other taxa had more ephemeral distributions as did the cereal aphids. The distribution of carabid larvae was disassociated from the distribution of cereal aphids for the first two sampling occasions indicating biocontrol was occurring. Other predatory groups showed both association and disassociation. Carabid larvae, Bathyphantes and total numbers of Linyphiidae showed a strong correlation with weed cover for two of the sample dates. Cereal aphids were disassociated from weed cover on three sampling occasions.

A key for freshwater invertebrates using fuzzy logic.

MOTIVATION: This paper summarizes a biological key using a fuzzy logic expert system. This approach allows the user to make some errors, be uncertain about some answers and not answer questions if unsure, but have an opportunity to identify unknown specimens correctly. This approach was adopted in order to develop a 'forgiving' key for users with little or no prior knowledge of identification. The system was implemented using a multi-media expert system builder, 'Matcher', operating in a Microsoft Windows environment. RESULTS: The paper reports the design issues for a key to identify freshwater invertebrates to family level and describes the types of questions used within the key, the fuzzy inference engine, the structure of the system and the methodology adopted for testing it. Following this, an empirical test is reported of the hypothesis that a fuzzy logic expert system can improve identification accuracy for a sample of intended users. Finally, the discussion considers the practicalities of using such a system as an aid to organism identification.

The uptake of cadmium and zinc by the bird-cherry oat aphid Rhopalosiphum padi (Homoptera:Aphididae) feeding on wheat grown on sewage sludge amended agricultural soil.

A greenhouse trial investigated the uptake of cadmium and zinc by the bird-cherry oat aphid (Rhopalosiphum padi) feeding on wheat grown on sewage sludge amended soil. The trial was conducted at application rates of 0, 5, 7.5, 10, 15 and 20 tonnes ha(-1) dry solids. Concentrations of Cd and Zn were within current UK limits for potentially toxic elements in soils amended with sewage sludge. Cd and Zn in wheat plants were significantly greater than controls. Batches of aphids feeding on the wheat also showed a significant increase in the uptake of Cd and Zn. This study demonstrates a potential route of exposure to Cd and Zn for the predators of cereal aphids.

Wool growth rate in vitro is independent of host animal nutrition, season, and the potential mediators of photoperiod, melatonin and prolactin.

In most sheep breeds, wool growth varies seasonally and is correlated with changes in photoperiod, temperature, and nutrition. Wool growth regulation by these factors may result from systemic changes, or to a response localized at the wool follicle. Possible roles of systemic and local factors have been examined here by comparison of wool growth responses in vitro and in vitro. Wool follicles were isolated and maintained under conditions facilitating fibre growth for at least 4 days. The wool growth rate by follicles isolated regularly over a 10 month period was invariate (P > 0.10), in contrast to a seasonally varying wool growth rate by follicles from the same animals in vivo (P < 0.001). Although a high energy, high protein diet increased wool growth in vivo (P < 0.05), cultured follicles isolated from these animals showed no change in growth rate (P > 0.10). These observations suggest that the regulation of wool growth by environmental factors is extrafollicular and that there is no carryover of the in vivo growth rate when follicles are isolated and systemic signals are therefore removed. Additional work discussed here examined the regulation of pelage by prolactin and melatonin, potential endocrine mediators of photoperiod. The fibre production rate by isolated follicles maintained in control media was not different to that of prolactin or melatonin supplemented follicles (P > 0.10). It is concluded that selective breeding of domesticated sheep has suppressed the response of follicles to regulation by prolactin and melatonin. Studies currently underway using in situ RT-PCR will provide further characterization of this conclusion.

Not all doom and gloom for child care.

Nursing Standard's coverage of reaction to the Audit Commission's report on services for children implies universal and comprehensive condemnation of the Commission's findings by nursing unions (Unions condemn Audit's report on HVs), News, June 15).

The effect of liming agricultural land on the chemistry and biology of the River Esk, north-west England.

A land-use study indicated that a reduction in agricultural liming may have been a major factor in the development of acid episodes and consequent fish kills in the River Esk and River Duddon. A field study was carried out to determine whether the reintroduction of catchment liming in the Esk valley could ameliorate acid episodes and thus prevent fish kills. Lime was applied to areas which had been limed in the past, comprising 10% of the Esk catchment. Flow, pH, calcium, aluminium, total humic substances, conductivity and invertebrates were monitored before and after liming. The River Duddon was monitored as a reference. There was a general reduction of the acidity of both the River Esk and the River Duddon during the study period. This appeared to be controlled by rainwater chemistry. There was little evidence for a major effect of liming on water chemistry which suggests that the mortalities of salmonids in the early 1980s were not due to a reduction in agricultural liming.