Trialling Biological Agents for the Management of Lesser Mealworm in Australian Broiler Houses

For approximately three decades the Australian broiler industry has relied heavily on the use of insecticides as its key tool for management of darkling beetle or lesser mealworm, Alphitobius diaperinus [Panzer] in broiler houses. The use of these chemicals over this period has been largely unchecked which has resulted in the development of strong insecticide resistance in many beetle populations from broiler farms. Although we are in a period now with an improved knowledge of managing resistance and the availability of new more effective insecticides that are currently marketed, the industry still requires more pest management options in order to inhibit development of resistance and reduce overall chemical use. In response to this need, ‘natural’ agents such as entomopathogenic nematodes and fungi were proposed as potential agents for managing darkling beetle populations in Australian broiler houses. Since 2007 laboratory and field studies have been undertaken to assess these agents. This report outlines these studies and discusses potential benefits to the Chicken Meat industry resulting from this research.

Extension of Chemical Phytotoxicity Testing Facility for Warm-Season Turfgrasses

The turf industry needs to access a range of more selective, effective and environmentally acceptable pesticides, which will help to address environmental concerns while maintaining the industry's internationally competitive status. This includes both new pesticides being developed globally for turf use and older generic chemicals previously registered for other agricultural purposes and now requiring extension of that registration for use in turf.

Serum testosterone levels during the menstrual-cycle and early-pregnancy in the bonnet monkey (macaca-radiata)

Abstract is not available.

Porous silica-based nanocapsules for targeted and controlled release of biocides

Develops a new technology for the delivery of biocides against agricultural pests, with biocides contained within silica nanocapsules which are themselves protected by an outer envelope, capable of being selectively broken down by the target pest. Will reduce the amount of biocide escaping into the environment, prolong the life of the biocide, reduce biocide usage rates, and reduce undesirable effects on non-target organisms.

Nutrient mass balance for Lockyer vegetable production

The potential for fertiliser use in Lockyer Valleys intensive vegetable production to impact on the Moreton Bay Waterways (MBW) is not well defined. Notwithstanding nutrient runoff through soil erosion of agricultural lands has been identified as a process that significantly contributes artificial fertiliser to the MBW (SEQ Healthy Waterways Draft Strategy 2006). In order to better understand this issue the present study undertakes a nutrient mass balance to evaluate nitrogen use efficiency in the intensive horticultural industry of the Lockyer Valley.

Sustainable productivity improvements in allium and solanaceous vegetable crops in Indonesia and sub-tropical Australia

The most important vegetable crops grown in Indonesia, and particularly lowland coastal production, are the true shallot and chilli. These crops are usually grown in rotation with rice but are far more valuable crops and are increasingly in high demand. They offer an opportunity for small farmers to generate extra income, increase farm profitability and shift away from subsistence production. However, the yield and profitability of shallot and chilli production is severely limited by a range of agronomic constraints. This project aims towards raising the productivity of allium (shallot and garlic) and chilli/capsicum cropping systems. The methodology will include a benchmarking survey and review of grower practices. This will be supplemented with physical surveys of crops for disease incidence and efficiency of fertiliser use. Once surveys are completed in Indonesia and the important pathogens identified, recommendations can be made for disease management. This will include review of chemical usage in Indonesia and Australia to provide best management guidelines for the application of insecticides, fungicides and other chemicals.

Differences in the Behavior of Luteinizing Hormones of Various Species at the Rat Gonadal Cell Receptor Site

The ability of different LH-like hormones, such as hCG, PMSG/equine (e) CG, ovine (o) LH, eLH, and rat (r) LH, to bind to and stimulate steroidogenesis in two types of rat gonadal cells was studied under the same experimental conditions. In both Leydig and granulosa cells, the maximal steroidogenic responses elicited by optimal doses of different LHs present during a 2-h incubation were comparable. However, if the cells were exposed to the different LHs for a brief period and then subjected to interference with hormone action by removing the unbound hormone from the medium by washing or adding specific antisera, differences were observed in the amount of steroid produced during subsequent incubation in hormone-free medium. Thus, in the case of hCG, either of these procedures carried out at 15 or 30 min of incubation had little inhibitory effect on the amount of steroid produced at 2 h, the latter being similar to that produced by cells incubated in the continued presence of hCG for 2 h. With eCG and rLH, the effect was dramatic, in that there was a total inhibition of subsequent steroidogenic response. In cells exposed to eLH and oLH, inhibition of subsequent steroidogenesis due to either removal of the free-hormone or addition of specific antisera at 15 or 30 min was only partial. Although all of the antisera used were equally effective in inhibiting the steroidogenic response to respective gonadotropins when added along with hormones at the beginning of incubation, differences were observed in the degree of inhibition of this response when the same antisera were added at later times of incubation. Thus, when antisera were added 60 min after the hormone, the inhibition of steroidogenesis was total (100%) for eCG, partial (10–40%) for eLH and oLH, and totally lacking in cells treated with hCG. From this, it appears that hCG bound to the receptor probably becomes unavailable for binding to its antibody with time, while in the case of eCG and other LHs used, the antibody can still inhibit the biological activity of the hormone. Studies with 125I-labeled hormones further supported the conclusion that hCG differs from all other LHs in being most tightly bound and, hence, least dissociable, while eCG and rLH dissociate most readily; oLH and eLH can be placed in between these hormones in the extent of their dissociability. (Endocrinology 116: 597–603,1985)

Controlling plant and fruit diseases in strawberry fields

Grey mould, powdery mildew and stem-end rot are major diseases affecting the strawberry industry. Some of the chemicals used are ineffective under wet weather, have limits to the number of applications allowed in a season or may become ineffective in the long-term because of the development of resistance in the fungi. We will assess the effectiveness of the chemicals currently used by the strawberry industry and whether the fruit rot fungi are resistant to these fungicides. We will screen other chemicals that are used to control these diseases in related crops. We will also evaluate new chemicals in collaboration with the crop protectant industry. We will also undertake similar work to control nematodes in strawberry fields.

Genetic Basis of Pituitary Adenoma Predisposition

Much of the global cancer research is focused on the most prevalent tumors; yet, less common tumor types warrant investigation, since A rare disorder is not necessarily an unimportant one . The present work discusses a rare tumor type, the benign adenomas of the pituitary gland, and presents the advances which, during the course of this thesis work, contributed to the elucidation of a fraction of their genetic background. Pituitary adenomas are benign neoplasms of the anterior pituitary lobe, accounting for approximately 15% of all intracranial tumors. Pituitary adenoma cells hypersecrete the hormones normally produced by the anterior pituitary tissue, such as growth hormone (GH) and prolactin (PRL). Despite their non-metastasizing nature, these adenomas can cause significant morbidity and have to be adequately treated; otherwise, they can compromise the patient s quality of life, due to conditions provoked by hormonal hypersecretion, such as acromegaly in the case of GH-secreting adenomas, or due to compressive effects to surrounding tissues. The vast majority of pituitary adenomas arise sporadically, whereas a small subset occur as component of familial endocrine-related tumor syndromes, such as Multiple Endocrine Neoplasia type 1 (MEN1) and Carney complex (CNC). MEN1 is caused by germline mutations in the MEN1 tumor suppressor gene (11q13), whereas the majority of CNC cases carry germline mutations in the PRKAR1A gene (17q24). Pituitary adenomas are also encountered in familial settings outside the context of MEN1 and CNC, but unlike in the latter syndromes, their genetic background until recently remained elusive. Evidence in previous literature supported the notion that a tumor suppressor gene on 11q13, residing very close to but still distinct from MEN1, causes genetic susceptibility to pituitary tumors. The aim of the study was to identify the genetic cause of a low penetrance form of Pituitary Adenoma Predisposition (PAP) in families from Northern Finland. The present work describes the methodological approach that led to the identification of aryl hydrocarbon receptor interacting protein (AIP) as the gene causing PAP. Combining chip-based technologies (SNP and gene expression arrays) with traditional gene mapping methods and genealogy data, we showed that germline AIP mutations cause PAP in familial and sporadic settings. PAP patients were diagnosed with mostly adenomas of the GH/PRL-secreting cell lineage. In Finland, two AIP mutations accounted for 16% of all patients diagnosed with GH-secreting adenomas, and for 40% of patients being younger than 35 years of age at diagnosis. AIP is suggested to act as a tumor suppressor gene, a notion supported by the nature of the identified mutations (most are truncating) and the biallelic inactivation of AIP in the tumors studied. AIP has been best characterized as a cytoplasmic interaction partner of aryl hydrocarbon receptor (AHR), also known as dioxin receptor, but it has other partners as well. The mechanisms that underlie AIP-mediated pituitary tumorigenesis are to date largely unknown and warrant further investigation. Because AIP was identified in the genetically homogeneous Finnish population, it was relevant to examine its contribution to PAP in other, more heterogeneous, populations. Analysis of pituitary adenoma patient series of various ethnic origins and differing clinical settings revealed germline AIP mutations in all cohorts studied, albeit with low frequencies (range 0.8-7.4%). Overall, PAP patients were typically diagnosed at a young age (range 8-41 years), mainly with GH-secreting adenomas, without strong family history of endocrine disease. Because many PAP patients did not display family history of pituitary adenomas, detection of the condition appeared challenging. AIP immunohistochemistry was tested as a molecular pre-screening tool on mutation-positive versus mutation-negative tumors, and proved to be a potentially useful predictor of PAP. Mutation screening of a large cohort of colorectal, breast, and prostate tumors did not reveal somatic AIP mutations. These tumors, apart from being the most prevalent among men and women worldwide, have been associated with acromegaly, particularly colorectal neoplasia. In this material, AIP did not appear to contribute to the pathogenesis of these common tumor types and other genes seem likely to play a role in such tumorigenesis. Finally, the contribution of AIP in pediatric onset pituitary adenomas was examined in a unique population-based cohort of sporadic pituitary adenoma patients from Italy. Germline AIP mutations may account for a subset of pediatric onset GH-secreting adenomas (in this study one of seven GH-secreting adenoma cases or 14.3%), and appear to be enriched among young (≤25 years old) patients. In summary, this work reveals a novel tumor susceptibility gene, namely AIP, which causes genetic predisposition to pituitary adenomas, in particular GH-secreting adenomas. Moreover, it provides molecular tools for identification of individuals predisposed for PAP. Further elaborate studies addressing the functional role of AIP in normal and tumor cells will hopefully expand our knowledge on endocrine neoplasia and reveal novel cellular mechanisms of pituitary tumorigenesis, including potential drug targets.

Growth differentiation factor 9 signalling in the ovary

In the ovary, two new members of the large TGF-beta superfamily of growth factors were discovered in the 1990s. The oocyte was shown to express two closely related growth factors that were named growth differentiation factor 9 (GDF-9) and growth differentiation factor 9B (GDF-9B). Both of these proteins are required for normal ovarian follicle development although their individual significance varies between species. GDF-9 and GDF-9B mRNAs are expressed in the human oocytes from the primary follicle stage onwards. This thesis project was aimed to define the signalling mechanisms utilized by the oocyte secreted GDF-9. We used primary cultures of human granulosa luteal cells (hGL) as our cell model, and recombinant adenovirus-mediated gene transfer in manipulating the TGF-b family signalling cascade molecules in these cells. Overexpression of the constitutively active forms of the seven type I receptors, the activin receptor-like kinases 1-7 (ALK1-7), using recombinant adenoviruses caused a specific activation of either the Smad1 or Smad2 pathway proteins depending on the ALK used. Activation of both Smad1 and Smad2 proteins also stimulated the expression of dimeric inhibin B protein in hGL cells. Treatment with recombinant GDF-9 protein induced the specific activation of the Smad2 pathway and stimulated the expression of inhibin betaB subunit mRNA as well as inhibin B protein secretion in our cell model. Recombinant GDF-9 also activated the Smad3-responsive CAGA-luciferase reported construct, and the GDF-9 response in hGL cells was markedly potentiated upon the overexpression of Alk5 by adenoviral gene transduction. Alk5 overexpression also enhanced the GDF-9 induced inhibin B secretion by these cells. Similarly, in a mouse teratocarcinoma cell line P19, GDF-9 could activate the Smad2/3 pathway, and overexpression of ALK5 in COS7 cells rendered them responsive to GDF-9. Furthermore, transfection of rat granulosa cells with small interfering RNA for ALK5 or overexpression of the inhibitory Smad7 resulted in dose-dependent suppression of GDF-9 effects. In conclusion, this thesis shows that both Smad1 and Smad2 pathways are involved in controlling the regulation of inhibin B secretion. Therefore, in addition to endocrine control of inhibin production by the pituitary gonadotropins, also local paracrine factors within in the ovary, like the oocyte-derived growth factors, may contribute to controlling inhibin secretion. This thesis shows as well that like other TGF-beta family ligands, also GDF-9 signalling is mediated by the canonical type I and type II receptors with serine/threonine kinase activity, and the intracellular transcription factors, the Smads. Although GDF-9 binds to the BMP type II receptor, its downstream actions are specifically mediated by the type I receptor, ALK5, and the Smad2 and Smad3 proteins.

In vitro development of islets from human adult pancreatic tissues

Transplantation of isolated islets from cadaver pancreas is a promising possibility for the optimal treatment of type 1 diabetes. The lack of islets is a major problem. Here we have investigated the possibility of generating islets in tissue culture of human pancreatic cells. We first reproduced a previously reported method of in vitro generation of endocrine cells from human adult pancreatic tissue. By tracing the bromodeoxyuridine-labeled cells in differentiated islet buds, we found that the pancreatic progenitor cells represented a subpopulation of cytokeratin 19 (CK19)-positive ductal cells. Serum-free medium and Matrigel overlay were essential for the endocrine differentiation. We then examined the involvement of preexisting islet cells in islet neogenesis. About 6-10% of endocrine cells dedifferentiated and acquired a transitional phenotype by coexpressing CK19. Significant cell proliferation was only observed in CK19-positive cells, but not in chromogranin A-positive endocrine cells. The in vitro-derived human islets were morphologically and functionally immature when compared with normal islets. Their insulin mRNA levels were only 4-5% of that found in fresh human islets, and glucose-stimulated insulin release was 3 times lower than that of control islets. Moreover, some immature endocrine cells coexpressed insulin and glucagon. After transplantation in nude mice, the in vitro-generated islets became mature with one type of hormone per endocrine cell. In addition, we also found that also in both fresh islet transplants many cells coexpressed endocrine markers and ductal marker CK19 as a sign of ductal to endocrine cell transition. Finally, we studied the effects of clinically used immunosuppressive drugs on precursor cell proliferation and differentiation. Mycophenolate mofetil (MMF) severely hampered duct-cell proliferation, and significantly reduced the total DNA content indicating its antiproliferative effect on the precursors. Tacrolimus mainly affected differentiated beta cells by decreasing the insulin content per DNA as well as the proportion of insulin-positive cells. Sirolimus and daclizumab did not show any individual or synergistic side effects suggesting that these drugs are amenable for use in clinical islet transplantation. In summary, we confirm the capacity of endocrine differentiation from progenitors present in the adult human pancreas. The plasticity of differentiated cell types of human pancreas may be a potential mechanism of human pancreas regeneration. Ductal cell differentiation into endocrine cells in transplanted islets may be an important factor in sustaining the long-term function of islet transplants. The immunosuppressive protocol is likely to be an important determinant of long-term clinical islet graft function. Moreover, these results provide new information on the mechanisms of pancreatic islet regeneration and provide the basis for the development of new strategies for the treatment of insulin deficient diabetes mellitus.

Molecular Details of Serum Resistance of Yersinia enterocolitica

In complement activation, Factor H (FH) and C4b-binding protein (C4bp) are the key regulators that prevent the complement cascade from attacking host tissues. Some bacteria may bind and deposit these regulators on their own surfaces and thus provide themselves with an efficient means to avoid complement activation. In consequence, bacteria resist complement-mediated lysis and opsonin-dependent phagocytosis. This study has demonstrated that Y. enterocolitica, similar to many other pathogens, recruits both FH and C4bp to its surface to ensure protection against the complement-mediated killing. YadA and Ail, the most crucial serum resistance factors of Y.enterocolitica, mediate the binding of FH and C4bp. FH - YadA interaction involves multiple higher structural motifs on the YadA stalk and the short consensus repeats (SCRs) of the entire polypeptide chain of FH. The Ail binding site on FH has been located to SCRs 6 and 7. The binding site for FH on Ail, however, remains undetermined. Both YadA- and Ail-bound regulators display full cofactor activity for FI-mediated cleavage of C3b/C4b. FH/C4bp-binding characteristics do, however, differ between YadA and Ail. In addition, Ail captures the regulators only in the absence of blocking lipopolysaccharide O-antigen and outer core, whereas YadA binds FH/C4bp independent of the presence of other surface factors Independent of mode of binding, however, YadA and Ail provide Y. enterocolitica a means to avoid complement-mediated lysis, enhancing chances for the bacteria to survive in the host during various phases of infection.

VEGFR-3 and Tie pathways in vascular network formation

The blood and lymphatic vascular systems are essential for life, but they may become harnessed for sinister purposes in pathological conditions. For example, tumors learn to grow a network of blood vessels (angiogenesis), securing a source of oxygen and nutrients for sustained growth. On the other hand, damage to the lymph nodes and the collecting lymphatic vessels may lead to lymphedema, a debilitating condition characterized by peripheral edema and susceptibility to infections. Promoting the growth of new lymphatic vessels (lymphangiogenesis) is an attractive approach to treat lymphedema patients. Angiopoietin-1 (Ang1), a ligand for the endothelial receptor tyrosine kinases Tie1 and Tie2. The Ang1/Tie2 pathway has previously been implicated in promoting endothelial stability and integrity of EC monolayers. The studies presented here elucidate a novel function for Ang1 as a lymphangiogenic factor. Ang1 is known to decrease the permeability of blood vessels, and could thus act as a more global antagonist of plasma leakage and tissue edema by promoting growth of lymphatic vessels and thereby facilitating removal of excess fluid and other plasma components from the interstitium. These findings reinforce the idea that Ang1 may have therapeutic value in conditions of tissue edema. VEGFR-3 is present on all endothelia during development, but in the adult its expression becomes restricted to the lymphatic endothelium. VEGF-C and VEGF-D are ligands for VEGFR-3, and potently promote lymphangiogenesis in adult tissues, with direct and remarkably specific effects on the lymphatic endothelium in adult tissues. The data presented here show that VEGF-C and VEGF-D therapy can restore collecting lymphatic vessels in a novel orthotopic model of breast cancer-related lymphedema. Furthermore, the study introduces a novel approach to improve VEGF-C/VEGF-D therapy by using engineered heparin-binding forms of VEGF-C, which induced the rapid formation of organized lymphatic vessels. Importantly, VEGF-C therapy also greatly improved the survival and integration of lymph node transplants. The combination of lymph node transplantation and VEGF-C therapy provides a basis for future therapy of lymphedema. In adults, VEGFR-3 expression is restricted to the lymphatic endothelium and the fenestrated endothelia of certain endocrine organs. These results show that VEGFR-3 is induced at the onset of angiogenesis in the tip cells that lead the formation of new vessel sprouts, providing a tumor-specific vascular target. VEGFR-3 acts downstream of VEGF/VEGFR-2 signals, but, once induced, can sustain angiogenesis when VEGFR-2 signaling is inhibited. The data presented here implicate VEGFR-3 as a novel regulator of sprouting angiogenesis along with its role in regulating lymphatic vessel growth. Targeting VEGFR-3 may provide added efficacy to currently available anti-angiogenic therapeutics, which typically target the VEGF/VEGFR-2 pathway.

Improved understanding of the damage, ecology, and management of mirids and stinkbugs in Bollgard II

In recent years mirids and stinkbugs have emerged as important sucking pests in cotton. While stinkbugs are causing damage to bolls, mirids are causing damage to seedlings, squares and bolls. With the increasing adoption of Bollgard II and IPM approaches the use of broad-spectrum chemicals to kill Helicoverpa has been reduced and as a result mirids and stinkbugs are building to levels causing damage to bolls later in crop growth stages. Studies on stinkbugs by Dr Moazzem Khan revealed that green vegetable bug (GVB) caused significant boll damage and yield loss. A preliminary study by Dr Khan on mirids revealed that high mirid numbers at later growth stages also caused significant boll damage and that damage caused by mirids and GVB were similar. Mirids and stinkbugs therefore demand greater attention in order to minimise losses caused by these pests and to develop IPM strategies against these pests to enhance gains in IPM that have been made with Bt-transgenic cotton. Progress in this area of research will maintain sustainability and profitability of the Australian cotton industry. Mirid damage at early growth stages of cotton (up to squaring stage) has been studied in detail by Dr Khan. He found that all ages of mirids cause damage to young plants and damage by mirid nymphs is cumulative. Maximum damage occurs when the insect reaches the 4th and 5th nymphal stages. He also found that mirid feeding causes shedding of small and medium squares, and damaged large squares develop as ‘parrot beak’ bolls. Detailed studies at the boll stage, such as which stage of mirids is most damaging or which age boll is most vulnerable to feeding, is lacking. This information is a prerequisite to developing an IPM strategy for the pest in later crop growth stages. Understanding population change of the pest over time in relation to crop development is an important aspect for developing management strategies for the pest which is lacking for mirids in BollgardII. Predators and parasitoids are integral components of any IPM system and play an important part in regulating pest populations. Some generalist predators such as ants, spiders, damsel bugs and assassin bugs are known to predate on mirids. Nothing is known about parasitoids of mirids. Since green mirid (GM), Creontiades dilutus, is indigenous to Australia it is likely that we have one or more parasitoids of this mirid in Australia, but that possibility has not been investigated yet. The impact of the GVB adult parasitoid, Trichopoda giacomelli, has been studied by Dr Khan who found that the fly is established in the released areas and continues to spread. However, to get wider and greater impact, the fly should be released in new locations across the valleys. The insecticides registered for mirids and stinkbugs are mostly non-selective and are extremely disruptive to a wide range of beneficial insects. Use of these insecticides at stage I and II will minimise the impact of existing IPM programs. Therefore less disruptive control tactics including soft chemicals for mirids and stinkbugs are necessary. As with soft chemicals, salt mixtures, biopesticides based on fungal pathogens and attractants based on plant volatiles may be useful tools in managing mirids and stinkbugs with less or no disruption. Dr Khan has investigated salt mixture against mirids and GVB. While salt mixtures are quite effective and less disruptive, they are quite chemical specific. Not all chemicals mixed with salt will give the desired benefit. Therefore further investigation is needed to identify those chemicals that are effective with salt mixture against mirids and 3 of 37 GVB. Dr Caroline Hauxwell of DPI&F is working on fungal pathogen-based biopesticides against mirids and GVB and Drs Peter Gregg and Alice Del Socorro of Australian Cotton CRC are working on plant volatile-based attractants against mirids. Depending on their findings, inclusion of fungal-based biopestcides and plant volatile-based attractants in developing a management system against mirids and stinkbugs in cotton could be an important component of an IPM approach.

The DOOR manual for plant nurseries

In the nursery industry, generic research conducted by government institutions is often not specific enough to be highly valued and adopted by the individual operator. Operators need practical solutions to their particular problems. Such problems almost invariably involve sets of conditions common to few other enterprises. This uniqueness reflects the almost infinite variation of options available in terms of species grown, media used, fertiliser, amendments and chemicals applied and the way water is supplied. The DOOR (Do Our Own Research) method advocates a relatively unexplored way of generating new, statistically sound research information in the nursery industry. The manual aims to enhance nursery operators' understanding and skills development in the following areas: critially evaluating opportunities and problems in the nursery environment, gathering relevant information, deriving and prioritising potential solutions to problems and opportunities, becoming familiar with the scientific method employed in testing potential solutions, carrying out statistically sound aand rigorous research, and developing recommendations that flow from the research information generated. The DOOR approach has application in a number of other industries and may provide important support at a time of declining research, development and extension investment by the public sector.