@article{davis_belikoff_scott_2018, title={Towards next generation maggot debridement therapy: Transgenic Lucilia sericata larvae that produce and secrete a human growth factor}, volume={26}, number={1}, journal={Wound Repair and Regeneration}, author={Davis, R. J. and Belikoff, E. J. and Scott, M. J.}, year={2018}, pages={A27–27} }
 @article{yan_linger_scott_2017, title={Building early-larval sexing systems for genetic control of the Australian sheep blow fly Lucilia cuprina using two constitutive promoters}, volume={7}, ISSN={2045-2322}, url={http://dx.doi.org/10.1038/s41598-017-02763-4}, DOI={10.1038/s41598-017-02763-4}, abstractNote={Transgenic sexing strains (TSS) that carry conditional female lethal genes are advantageous for genetic control programs based on the sterile insect technique (SIT). It is desirable if females die early in development as larval diet is a major cost for mass production facilities. This can be achieved by using a gene promoter that is only active in embryos to drive expression of the tetracycline transactivator (tTA), the transcription factor commonly used in two-component TSS. While an embryo-specific promoter is ideal it may not be essential for assembling an effective TSS as tTA can be repressed by addition of tetracycline to the diet at larval and/or adult stages. Here we have investigated this idea by isolating and employing the promoters from the Lucilia spitting image and actin 5C genes to drive tTA expression in embryos and later stages. L. cuprina TSS with the tTA drivers and tTA-regulated tetO-Lshid effectors produced only females when raised on a limited tetracycline diet. The Lshid transgene contains a sex-specific intron and as a consequence only females produce LsHID protein. TSS females died at early larval stages, which makes the lines advantageous for an SIT program.}, number={1}, journal={Scientific Reports}, publisher={Springer Science and Business Media LLC}, author={Yan, Ying and Linger, Rebecca J. and Scott, Maxwell J.}, year={2017}, month={May} }
 @article{linger_belikoff_yan_li_wantuch_fitzsimons_scott_2016, title={Towards next generation maggot debridement therapy: transgenic Lucilia sericata larvae that produce and secrete a human growth factor}, volume={16}, ISSN={1472-6750}, url={http://dx.doi.org/10.1186/s12896-016-0263-z}, DOI={10.1186/s12896-016-0263-z}, abstractNote={Diabetes and its concurrent complications impact a significant proportion of the population of the US and create a large financial burden on the American health care system. FDA-approved maggot debridement therapy (MDT), the application of sterile laboratory-reared Lucilia sericata (green bottle fly) larvae to wounds, is a cost-effective and successful treatment for diabetic foot ulcers and other medical conditions. Human platelet derived growth factor-BB (PDGF-BB) is a secreted dimeric peptide growth factor that binds the PDGF receptor. PDGF-BB stimulates cell proliferation and survival, promotes wound healing, and has been investigated as a possible topical treatment for non-healing wounds. Genetic engineering has allowed for expression and secretion of human growth factors and other proteins in transgenic insects. Here, we present a novel concept in MDT technology that combines the established benefits of MDT with the power of genetic engineering to promote healing. The focus of this study is to create and characterize strains of transgenic L. sericata that express and secrete PDGF-BB at detectable levels in adult hemolymph, whole larval lysate, and maggot excretions/ secretions (ES), with potential for clinical utility in wound healing. We have engineered and confirmed transgene insertion in several strains of L. sericata that express human PDGF-BB. Using a heat-inducible promoter to control the pdgf-b gene, pdgf-b mRNA was detected via semi-quantitative PCR upon heat shock. PDGF-BB protein was also detectable in larval lysates and adult hemolymph but not larval ES. An alternative, tetracycline-repressible pdgf-b system mediated expression of pdgf-b mRNA when maggots were raised on diet that lacked tetracycline. Further, PDGF-BB protein was readily detected in whole larval lysate as well as larval ES. Here we show robust, inducible expression and production of human PDGF-BB protein from two conditional expression systems in transgenic L. sericata larvae. The tetracycline-repressible system appears to be the most promising as PDGF-BB protein was detectable in larval ES following induction. Our system could potentially be used to deliver a variety of growth factors and anti-microbial peptides to the wound environment with the aim of enhancing wound healing, thereby improving patient outcome in a cost-effective manner.}, number={1}, journal={BMC Biotechnology}, publisher={Springer Science and Business Media LLC}, author={Linger, Rebecca J. and Belikoff, Esther J. and Yan, Ying and Li, Fang and Wantuch, Holly A. and Fitzsimons, Helen L. and Scott, Maxwell J.}, year={2016}, month={Mar} }
 @article{linger_belikoff_scott_2015, title={Dosage Compensation of X-Linked Muller Element F Genes but Not X-Linked Transgenes in the Australian Sheep Blowfly}, volume={10}, ISSN={1932-6203}, url={http://dx.doi.org/10.1371/journal.pone.0141544}, DOI={10.1371/journal.pone.0141544}, abstractNote={In most animals that have X and Y sex chromosomes, chromosome-wide mechanisms are used to balance X-linked gene expression in males and females. In the fly Drosophila melanogaster, the dosage compensation mechanism also generally extends to X-linked transgenes. Over 70 transgenic lines of the Australian sheep blowfly Lucilia cuprina have been made as part of an effort to develop male-only strains for a genetic control program of this major pest of sheep. All lines carry a constitutively expressed fluorescent protein marker gene. In all 12 X-linked lines, female larvae show brighter fluorescence than male larvae, suggesting the marker gene is not dosage compensated. This has been confirmed by quantitative RT-PCR for selected lines. To determine if endogenous X-linked genes are dosage compensated, we isolated 8 genes that are orthologs of genes that are on the fourth chromosome in D. melanogaster. Recent evidence suggests that the D. melanogaster fourth chromosome, or Muller element F, is the ancestral X chromosome in Diptera that has reverted to an autosome in Drosophila species. We show by quantitative PCR of male and female DNA that 6 of the 8 linkage group F genes reside on the X chromosome in L. cuprina. The other two Muller element F genes were found to be autosomal in L. cuprina, whereas two Muller element B genes were found on the same region of the X chromosome as the L. cuprina orthologs of the D. melanogaster Ephrin and gawky genes. We find that the L. cuprina X chromosome genes are equally expressed in males and females (i.e., fully dosage compensated). Thus, unlike in Drosophila, it appears that the Lucilia dosage compensation system is specific for genes endogenous to the X chromosome and cannot be co-opted by recently arrived transgenes.}, number={10}, journal={PLOS ONE}, publisher={Public Library of Science (PLoS)}, author={Linger, Rebecca J. and Belikoff, Esther J. and Scott, Maxwell J.}, editor={Marais, Gabriel ABEditor}, year={2015}, month={Oct}, pages={e0141544} }
 @article{edman_linger_belikoff_li_sze_tarone_scott_2014, title={Functional characterization of calliphorid cell death genes and cellularization gene promoters for controlling gene expression and cell viability in early embryos}, volume={24}, ISSN={0962-1075 1365-2583}, url={http://dx.doi.org/10.1111/imb.12135}, DOI={10.1111/imb.12135}, abstractNote={The New World screwworm fly, Cochliomyia hominivorax, and the Australian sheep blow fly, Lucilia cuprina, are major pests of livestock. The sterile insect technique was used to eradicate C. hominivorax from North and Central America. This involved area‐wide releases of male and female flies that had been sterilized by radiation. Genetic systems have been developed for making ‘male‐only’ strains that would improve the efficiency of genetic control of insect pests. One system involves induction of female lethality in embryos through activation of a pro‐apoptotic gene by the tetracycline‐dependent transactivator. Sex‐specific expression is achieved using an intron from the transformer gene, which we previously isolated from several calliphorids. In the present study, we report the isolation of the promoters from the C. hominivorax slam and Lucilia sericata bnk cellularization genes and show that these promoters can drive expression of a GFP reporter gene in early embryos of transgenic L. cuprina. Additionally, we report the isolation of the L. sericata pro‐apoptotic hid and rpr genes, identify conserved motifs in the encoded proteins and determine the relative expression of these genes at different stages of development. We show that widespread expression of the L. sericata pro‐apoptotic genes was lethal in Drosophila melanogaster. The isolated gene promoters and pro‐apoptotic genes could potentially be used to build transgenic embryonic sexing strains of calliphorid livestock pests.}, number={1}, journal={Insect Molecular Biology}, publisher={Wiley}, author={Edman, R. M. and Linger, R. J. and Belikoff, E. J. and Li, F. and Sze, S.‐H. and Tarone, A. M. and Scott, M. J.}, year={2014}, month={Sep}, pages={58–70} }
 @article{li_wantuch_linger_belikoff_scott_2014, title={Transgenic sexing system for genetic control of the Australian sheep blow fly Lucilia cuprina}, volume={51}, ISSN={0965-1748}, url={http://dx.doi.org/10.1016/j.ibmb.2014.06.001}, DOI={10.1016/j.ibmb.2014.06.001}, abstractNote={The New World screwworm and the Australian sheep blowfly Lucilia cuprina are devastating pests of livestock. The larvae of these species feed on the tissue of the living animal and can cause death if untreated. The sterile insect technique or SIT was used to eradicate screwworm from North and Central America. This inspired efforts to develop strains containing complex chromosomal rearrangements for genetic control of L. cuprina in Australia. Although one field trial was promising, the approach was abandoned due to costs and difficulties in mass rearing the strain. As the efficiency of SIT can be significantly increased if only sterile males are released, we have developed transgenic strains of L. cuprina that carry a dominant tetracycline repressible female lethal genetic system. Lethality is due to overexpression of an auto-regulated tetracycline repressible transactivator (tTA) gene and occurs mostly at the pupal stage. Dominant female lethality was achieved by replacing the Drosophila hsp70 core promoter with a Lucilia hsp70 core promoter-5'UTR for tTA overexpression. The strains carry a dominant strongly expressed marker that will facilitate identification in the field. Interestingly, the sexes could be reliably sorted by fluorescence or color from the early first instar larval stage as females that overexpress tTA also overexpress the linked marker gene. Male-only strains of L. cuprina developed in this study could form the basis for a future genetic control program. Moreover, the system developed for L. cuprina should be readily transferrable to other major calliphorid livestock pests including the New and Old World screwworm.}, journal={Insect Biochemistry and Molecular Biology}, publisher={Elsevier BV}, author={Li, Fang and Wantuch, Holly A. and Linger, Rebecca J. and Belikoff, Esther J. and Scott, Maxwell J.}, year={2014}, month={Aug}, pages={80–88} }