Environmental control for layers

Light patterns have less effect on numbers of eggs laid by current stocks than on those of forty years ago, but the principles have not changed. Ovarian activity is stimulated by increasing photoperiods and suppressed by decreasing photoperiods. The light pattern used during rearing can still have large effects on age at 50% lay, even for modern stocks. Early sexual maturity maximises egg numbers but gives smaller eggs. Late maturity maximises egg size at the expense of numbers. The relationship between egg output (g/hen d) and age at first egg is curvilinear, with maximum yield occurring in flocks maturing in about the centre of their potential range. Fancy patterns of increasing daylength after maturity are probably not justified. A flock held on a constant 14h day will lay as many eggs as one given step up lighting. Intermittent lighting saves about 5% of feed consumption with no loss of output, provided that the feed has adequate amino acid content to allow for the reduced feed intake. Producers with light-proof laying houses should be taking advantage of intermittent lighting. The recommended light intensity for laying houses is still 10 lx, although the physiological threshold for response to changes in photoperiod is closer to 2 lx. Very dim (0.05 lx) light filtering into blacked out houses will not stimulate the hypothalamic receptors responsible for photo-sexual responses, but may affect the bird's biological clock, which can alter its response to a constant short photoperiod. Feed intake shows a curvilinear dependence on environmental temperature. At temperatures below the panting threshold, performance can be maintained by adjusting the feed so as to maintain an adequate intake of critical amino acids. Above the panting threshold, the hen is unable to take in enough energy to maintain normal output. There is no dietary modification which can effectively offset this problem. Diurnally cycling temperatures result in feed intake and egg production equivalent to that observed under a constant temperature equal to the mean of the cycle. When the poultry house is cooler at night than by day, it helps to provide light so that the birds can feed during the cooler part of the cycle.

Design and formative evaluation of an information kiosk on cattle health for landless cattle owners

This paper describes and analyses the experience of designing, installing and evaluating a farmer-usable touch screen information kiosk on cattle health in a veterinary institution in Pondicherry. The contents of the kiosk were prepared based on identified demands for information on cattle health, arrived at through various stakeholders meetings. Information on these cattle diseases and conditions affecting the livelihoods of the poor was provided through graphics, text and audio back-up, keeping in mind the needs of landless and illiterate poor cattle owners. A methodology for kiosk evaluation based on the feedback obtained from kiosk facilitator, critical group reflection and individual users was formulated. The formative evaluation reveals the potential strength this ICT has in transferring information to the cattle owners in a service delivery centre. Such information is vital in preventing diseases and helps cattle owners to present and treat their animals at an early stage of disease condition. This in turn helps prevent direct and indirect losses to the cattle owners. The study reveals how an information kiosk installed at a government institution as a freely accessible source of information to all farmers irrespective of their class and caste can help in transfer of information among poor cattle owners, provided periodic updating, interactivity and communication variability are taken care of. Being in the veterinary centre, the kiosk helps stimulate dialogue, and facilitates demand of services based on the information provided by the kiosk screens.

Effect of prolonged intravenous glucose and essential amino acid infusion on nitrogen balance, muscle protein degradation and ubiquitin-conjugating enzyme gene expression in calves

Background: Intravenous infusions of glucose and amino acids increase both nitrogen balance and muscle accretion. We hypothesised that co-infusion of glucose ( to stimulate insulin) and essential amino acids (EAA) would act additively to improve nitrogen balance by decreasing muscle protein degradation in association with alterations in muscle expression of components of the ubiquitin-proteasome proteolytic pathway. Methods: We examined the effect of a 5 day intravenous infusions of saline, glucose, EAA and glucose + EAA, on urinary nitrogen excretion and muscle protein degradation. We carried out the study in 6 restrained calves since ruminants offer the advantage that muscle protein degradation can be assessed by excretion of 3 methyl-histidine and multiple muscle biopsies can be taken from the same animal. On the final day of infusion blood samples were taken for hormone and metabolite measurement and muscle biopsies for expression of ubiquitin, the 14-kDa E2 ubiquitin conjugating enzyme, and proteasome sub-units C2 and C8. Results: On day 5 of glucose infusion, plasma glucose, insulin and IGF-1 concentrations were increased while urea nitrogen excretion and myofibrillar protein degradation was decreased. Co-infusion of glucose + EAA prevented the loss of urinary nitrogen observed with EAA infusions alone and enhanced the increase in plasma IGF-1 concentration but there was no synergistic effect of glucose + EAA on the decrease in myofibrillar protein degradation. Muscle mRNA expression of the ubiquitin conjugating enzyme, 14-kDa E2 and proteasome sub-unit C2 were significantly decreased, after glucose but not amino acid infusions, and there was no further response to the combined infusions of glucose + EAA. Conclusion: Prolonged glucose infusion decreases myofibrillar protein degradation, prevents the excretion of infused EAA, and acts additively with EAA to increase plasma IGF-1 and improve net nitrogen balance. There was no evidence of synergistic effects between glucose + EAA infusion on muscle protein degradation or expression of components of the ubiquitin-proteasome proteolytic pathway.

Plant variety protection in developing countries: A view from the private seed industry in India

Many developing countries are currently engaged in designing and implementing plant variety protection systems. Encouraging private investment in plant breeding is the key rationale for extending intellectual property rights to plant varieties. However, the design of plant variety protection systems in developing countries has been dominated by concerns regarding the inequities of a plant variety protection system, especially the imbalance in the reward structure between plant breeders and farmers. The private seed industry, a key stakeholder in plant variety protection, appears to be playing only a peripheral role in the design of the intellectual property rights regime. This paper explores the potential response of the private seed industry in India to plant variety protection legislation based on a survey of major plant breeding companies. The survey finds that the private seed industry in India is generally unenthusiastic about the legislation and plant variety protection is likely to have only a very limited impact on their research profile and expenditures on plant breeding. Measures designed to curb the 'excessive' profits of breeders, farmers' rights provisions and poor prospects for enforcement of rights are seen to be seriously diluting breeders' rights, leaving few incentives for innovation. If the fundamental objective of plant variety protection is to stimulate private investment in plant breeding, then developing countries need to seriously address the question of improving appropriability of returns from investment.

The stimulation of mitogenic signaling pathways by N-POMC peptides

The N-terminal fragment of pro-opiomelancortin (POMC) has been shown previously to act as an adrenal mitogen. However, little is known about the molecular mechanisms by which mitogenesis is stimulated, although it has been shown that N-POMC1-28 Stimulates the ERK pathway in human H295R cells. We have investigated signaling stimulated by N-POMC1-28 and N-POMC1-49 in the mouse Y1 cell line and found that both peptides stimulate ERK phosphorylation with maximal stimulation being achieved within 5 min. Similar results were observed for both MEK and c-Raf phosphorylation, although N-POMC1-49 stimulated the phosphorylation of Akt more robustly than N-POMC1-28. We also investigated the expression of tyrosine kinase receptors in adrenal cells. PCR utilizing degenerate primers was performed on cDNA from both Y1 cells and rat adrenal tissue. Sequencing of 114 clones from each cDNA population revealed the expression of a number of receptors, several of which have not been described previously in the adrenal. (C) 2008 Elsevier Ireland Ltd. All rights reserved.

Water deficits promote flowering in Rhododendron via regulation of pre and post initiation development

Flowering is generally considered to be advanced by water deficits in many woody perennial species. A long-standing paradigm being that as a plant senses severe environmental conditions resources are diverted away from vegetative growth and towards reproduction before death. It is demonstrated that in Rhododendron flowering is promoted under water deficit treatments. However, the promotion of flowering is not achieved via all increase in floral initiation, but through separate developmental responses. If regulated deficit irrigation (RDI) is imposed prior to the time of initiation, fewer vegetative nodes are formed before the apical meristems switch to floral initiation, and chronologically, floral initiation occurs earlier. Both RDI and partial rootzone drying (PRD) treatments stimulate the development of more flowers Oil each inflorescence if the treatments are continued after the plant has undergone floral initiation. However, floral initiation is inhibited by soil water deficits. If the soil water deficit continues beyond the stages of floral development then anthesis call occur prematurely oil the fully formed floral buds without a need for a winter chilling treatment. It is hypothesised that inhibition of floral initiation in plants experiencing severe soil water deficits results from the inhibitory action Of ABA transportation to the apical meristem from stressed roots. It is demonstrated that ABA applications to well-watered Rhododendron inhibit floral initiation. (c) 2008 Elsevier B.V. All rights reserved.

Evidence of a possible role for Lys-gamma 3-MSH in the regulation of adipocyte function

Lys-gamma 3-MSH is a melanocortin peptide derived from the C-terminal of the 16 kDa fragment of POMC. The physiological role of Lys-gamma 3-MSH is unclear, although it has previously been shown that, although not directly steroidogenic, it can act to potentiate the steroidogenic response of adrenal cortical cells to ACTH. This synergistic effect appears to be correlated with an ability to increase the activity of hormone sensitive lipase (HSL) and therefore the rate of cholesterol ester hydrolysis. Ligand binding studies have suggested that high-affinity binding sites for Lys-gamma 3-MSH exist in the adrenal gland and a number of other rat tissues that express HSL, including adipose, skeletal muscle and testes. To investigate the hypothesis that Lys-gamma 3-MSH may play a wider role in cholesterol and lipid metabolism, we tested the effect of Lys-gamma 3-MSH on lipolysis, an HSL-mediated process, in 3T3-L1 adipocytes. In comparison with other melanocortin peptides, Lys-gamma 3-MSH was found to be a potent stimulator of lipolysis. It was also able to phosphorylate HSL at key serine residues and stimulate the hyper-phosphorylation of perilipin A. The receptor through which the lipolytic actions of Lys-gamma 3-MSH are being mediated is not clear. Attempts to characterise this receptor suggest that either the pharmacology of the melanocortin receptor 5 in 3T3-L1 adipocytes is different from that described when expressed in heterologous systems or the possibility that a further, as yet uncharacterised, receptor exists.

Epidermal growth factor-stimulated extravillous cytotrophoblast motility is mediated by the activation of PI3-K, Akt and both p38 and p42/44 mitogen-activated protein kinases

BACKGROUND: Trophoblast invasion is a temporally and spatially regulated scheme of events that can dictate pregnancy outcome. Evidence suggests that the potent mitogen epidermal growth factor (EGF) regulates cytotrophoblast (CTB) differentiation and invasion during early pregnancy. METHODS AND RESULTS: In the present study, the first trimester extravillous CTB cell line SGHPL-4 was used to investigate the signalling pathways involved in the motile component of EGF-mediated CTB migration/invasion. EGF induced the phosphorylation of the phosphatidylinositol 3-kinase (PI3-K)-dependent proteins, Akt and GSK-3β as well as both p42/44 MAPK and p38 mitogen-activated protein kinases (MAPK). EGF-stimulated motility was significantly reduced following the inhibition of PI3-K (P < 0.001), Akt (P < 0.01) and both p42/44 MAPK (P < 0.001) and p38 MAPKs (P < 0.001) but not the inhibition of GSK-3β. Further analysis indicated that the p38 MAPK inhibitor SB 203580 inhibited EGF-stimulated phosphorylation of Akt on serine 473, which may be responsible for the effect SB 203580 has on CTB motility. Although Akt activation leads to GSK-3β phosphorylation and the subsequent expression of β-catenin, activation of this pathway by 1-azakenpaullone was insufficient to stimulate the motile phenotype. CONCLUSION: We demonstrate a role for PI3-K, p42/44 MAPK and p38 MAPK in the stimulation of CTB cell motility by EGF, however activation of β-catenin alone was insufficient to stimulate cell motility.

Effect of sulphation on the oestrogen agonist activity of the phytoestrogens genistein and daidzein in MCF-7 human breast cancer cells

The phytoestrogens genistein, daidzein and the daidzein metabolite equol have been shown previously to possess oestrogen agonist activity. However, following consumption of soya diets, they are found in the body not only as aglycones but also as metabolites conjugated at their 4'- and 7-hydroxyl groups with sulphate. This paper describes the effects of monosulphation on the oestrogen agonist properties of these three phytoestrogens in MCF-7 human breast cancer cells in terms of their relative ability to compete with [H-3]oestradiol for binding to oestrogen receptor (ER), to induce a stably transfected oestrogen-responsive reporter gene (ERE-CAT) and to stimulate cell growth. In no case did sulphation abolish activity. The 4'-sulphadon of genistein reduced oestrogen agonist activity to a small extent in whole-cell assays but increased the relative binding affinity to ER. The 7-sulphation of genistein, and also of equol, reduced oestrogen agonist activity substantially in all assays. By contrast, the position of monosulphation of daidzein acted in an opposing manner on oestrogen agonist activity. Sulphation at the 4'-position of daidzein resulted in a modest reduction in oestrogen agonist activity but sulphation of daidzein at the 7-position resulted in an increase in oestrogen agonist activity. Molecular modelling and docking studies suggested that the inverse effects of sulphation could be explained by the binding of daidzein into the ligand-binding domain of the ER in the opposite orientation compared with genistein and equol. This is the first report of sulphation enhancing activity of an isoflavone and inverse effects of sulphation between individual phytoestrogens.

Immunogenicity of the outer domain of a HIV-1 clade C gp120

Background: The possibility that a sub domain of a C clade HIV-1 gp120 could act as an effective immunogen was investigated. To do this, the outer domain ( OD) of gp120(CN54) was expressed and characterized in a construct marked by a re-introduced conformational epitope for MAb 2G12. The expressed sequence showed efficient epitope retention on the isolated ODCN54 suggesting authentic folding. To facilitate purification and subsequent immunogenicity ODCN54 was fused to the Fc domain of human IgGl. Mice were immunised with the resulting fusion proteins and also with gp120(CN54)-Fc and gp120 alone. Results: Fusion to Fc was found to stimulate antibody titre and Fc tagged ODCN54 was substantially more immunogenic than non-tagged gp120. Immunogenicity appeared the result of Fc facilitated antigen processing as immunisation with an Fc domain mutant that reduced binding to the FcR lead to a reduction in antibody titre when compared to the parental sequence. The breadth of the antibody response was assessed by serum reaction with five overlapping fragments of gp120(CN54) expressed as GST fusion proteins in bacteria. A predominant anti-inner domain and anti-V3C3 response was observed following immunisation with gp120(CN54)-Fc and an anti-V3C3 response to the ODCN54-Fc fusion. Conclusion: The outer domain of gp120(CN54) is correctly folded following expression as a C terminal fusion protein. Immunogenicity is substantial when targeted to antigen presenting cells but shows V3 dominance in the polyvalent response. The gp120 outer domain has potential as a candidate vaccine component.

Tachykinins regulate the function of platelets

Evidence has been mounting for peripheral functions for tachykinins, a family of neuropeptides including substance P (SP), neurokinin A, and neurokinin B, which are recognized for their roles in the central and peripheral nervous system. The recent discovery of 4 new members of this family, the endokinins (EKA, B, C, and 13), which are distributed peripherally, adds support to the notion that tachykinins have physiologic/endocrine roles in the periphery. In the present study we report a fundamental new function for tachykinins in the regulation of platelet function. We show that SP stimulates platelet aggregation, and underlying this is the intracellular mobilization of calcium and degranulation. We demonstrate the presence of the tachykinin receptors NK1 and NK3 in platelets and present evidence for the involvement of NK1 in SP-mediated platelet aggregation. Platelets were found to contain SP-like immunoreactivity that is secreted upon activation implicating SP-like substances in the autocrine/paracrine regulation of these cells. Indeed, NK1-blocking antibodies inhibited aggregation in response to other agonists. Of particular note is the observation that EKA/B cross-react in the SP immunoassay and are also able to stimulate platelet activation. Together our data implicate tachykinins, specifically SP and EKA/B, in the regulation of platelet function. (C) 2004 by The American Society of Hematology.

Functional coupling of the human dopamine D-2 receptor with G alpha(i1), G alpha(i2), G alpha(i3) and G alpha(o) G proteins: evidence for agonist regulation of G protein selectivity

1 The human dopamine D-2long (D-2L) receptor was expressed with four different G proteins in Sf9 cells using the baculovirus expression system. When co-expressed with G(i)/G(o) G proteins (G(i1)alpha, G(i2)alpha, G(i3)alpha, or G(o)alpha, plus Gbeta(1) and Ggamma(2)) the receptor displayed a high-affinity binding site for the agonists (dopamine and NPA), which was sensitive to GTP (100 mum), demonstrating interaction between the receptor and the different G proteins. 2 The receptor to G protein ratio (R: G ratio) was evaluated using [H-3]-spiperone saturation binding (R) and [S-35]-GTPgammaS saturation binding (G). R: G ratios of 1: 12, 1: 3, 1: 14 and 1: 5 were found for G(i1), G(i2), G(i3), and Go preparations, respectively. However, when R:G ratios of 1:2 and 1: 12 were compared for G(i2) and G(o), no difference was found for the stimulation of [S-35]-GTPgammaS binding. 3 Several agonists were tested for their ability to stimulate [S-35]-GTPgammaS binding to membranes co-expressing the receptor and various G proteins. All the compounds tested showed agonist activity in preparations expressing G(i3) and G(o). However, for G(i2) and G(i1) preparations, compounds such as S-(-)-3-PPP and p-tyramine were unable to stimulate [S-35]-GTPyS binding. 4 Most of the compounds showed higher relative efficacies (compared to dopamine) and higher potencies in the preparation expressing G(o). Comparison of the effects of different agonists in the different preparations showed that each agonist differentially activates the four G proteins. 5 We conclude that the degree of selectivity of G protein activation by the D-2L receptor can depend on the conformation of the receptor stabilised by an agonist.

Effect of water stress on infection by species of honey fungus (Armillaria mellea and A. gallica)

Isolates of Armillaria mellea and A. gallica that differed in virulence to healthy blackcurrant, strawberry, Lawson cypress and privet were used to inoculate plants exposed to different watering regimes. Host plants from which water had either been withheld or their roots kept constantly flooded with water, both showed increased susceptibility compared to those plants, which had been watered regularly. At the end of the period of stress, roots from randomly selected plants from each treatment were harvested. Following chemical analysis of the roots for protein, lipids, and carbohydrates including starch, in vitro assays were carried out with these substances. The increased amounts of these nutrients in both groups of stressed plants are sufficient to stimulate the growth of both A. mellea and A. gallica and enhance their virulence.

The component polypeptide chains of bovine insulin nucleate or inhibit aggregation of the parent protein in a conformation-dependent manner

Amyloid fibrils are typically rigid, unbrariched structures with diameters of similar to 10 nm and lengths up to several micrometres, and are associated with more than 20 diseases including Alzheimer's disease and type II diabetes. Insulin is a small, predominantly alpha-helical protein consisting of 51 residues in two disulfide-linked polypeptide chains that readily assembles into amyloid fibrils under conditions of low PH and elevated temperature. We demonstrate here that both the A-chain and the B-chain of insulin are capable of forming amyloid fibrils in isolation under similar conditions, with fibrillar morphologies that differ from those composed of intact insulin. Both the A-chain and B-chain fibrils were found to be able to cross-seed the fibrillization of the parent protein, although these reactions were substantially less efficient than self-seeding with fibrils composed of full-length insulin. In both cases, the cross-seeded fibrils were morphologically distinct from the seeding, material, but shared common characteristics with typical insulin fibrils, including a very similar helical repeat. The broader distribution of heights of the cross-seeded fibrils compared to typical insulin fibrils, however, indicates that their underling protofilament hierarchy may be subtly different. In addition, and remarkably in view of this seeding behavior, the soluble forms of the A-chain and B-chain peptides were found to be capable of inhibiting insulin fibril formation. Studies using mass spectrometry suggest that this behavior might be attributable to complex formation between insulin and the A-chain and B-chain peptides. The finding that the same chemical form of a polypeptide chain in different physical states can either stimulate or inhibit the conversion of a protein into amyloid fibrils sheds new light on the mechanisms underlying fibril formation, fibril strain propagation and amyloid disease initiation and progression. (c) 2006 Elsevier Ltd. All rights reserved.

Microbial species involved in production of 1,2-sn-diacylglycerol and effects of phosphatidylcholine on human fecal microbiota

1,2-sn-Diacylglycerols (DAGs) are activators of protein kinase C (PKQ, which is involved in the regulation of colonic mucosal proliferation. Extracellular DAG has been shown to stimulate the growth of cancer cell lines in vitro and may therefore play an important role in tumor promotion. DAG has been detected in human fecal extracts and is thought to be of microbial origin. Hitherto, no attempts have been made to identify the predominant fecal bacterial species involved in its production. We therefore used anaerobic batch culture systems to determine whether fecal bacteria could utilize phosphatidylcholine (0.5% [wt/vol]) to produce DAG. Production was found to be dependent upon the presence of the substrate and was enhanced in the presence of high concentrations of deoxycholate (5 and 10 mM) in the growth medium. Moreover, its production increased with the pH, and large inter- and intraindividual variations were observed between cultures seeded with inocula from different individuals. Clostridia and Escherichia coli multiplied in the fermentation systems, indicating their involvement in phosphatidylcholine metabolism. On the other hand, there was a significant decrease in the number of Bifidobacterium spp. in the presence of phosphatidylcholine. Pure-culture experiments showed that 10 of the 12 strains yielding the highest DAG levels (>50 nmol/ml) were isolated from batch culture enrichments run at pH 8.5. We found that the strains capable of producing large amounts of DAG were predominantly Clostridium bifermentans (8 of 12), followed by Escherichia coli (2 of 12). Interestingly, one DAG-producing strain was Bifidobacterium infantis, which is often considered a beneficial gut microorganism. Our results have provided further evidence that fecal bacteria can produce DAG and that specific bacterial groups are involved in this process. Future strategies to reduce DAG formation in the gut should target these species.