Explaining the success of Roman freedmen : a pseudo-Darwinian approach

textIn Roman society, freed slaves were elevated to a citizen-like status, yet they never had the full rights of their free-born counterparts. Despite the inequality of the system, many freedmen appear to have found great success in the realm of business. This report endeavors to reveal why it was that this group prospered within the Roman economy using a pseudo-Darwinian perspective. Scholarship has, for the most part, tended to avoid Darwinian lines of thought in sociological studies but this report shows the power of this type of thinking. The first chapter clarifies the nature of slavery in the Roman world and the wide variety of experiences that slaves could have. Chapter two considers the different ways that slaves could be manumitted and how a freedman’s status could differ depending on the formality of his release from servitude. The third chapter examines the literary representations of freedmen in the genre of comedy and Petronius’ Satyricon. Chapter four turns to the archaeological evidence and provides a sense of how freedmen represented themselves to the wider community. Lastly, the fifth chapter, using a pseudo-Darwinian model, will show that the image of the successful freedman is not an anomaly of the archaeological record or a trope of Latin literature but an inevitable outcome of the intense selection that slaves underwent.Classic

Groups of graphs of groups

We classify all groups of color preserving automorphisms (isometries) of edge colored complete graphs derived from finite groups

Artificial mirtron-mediated gene knockdown:Functional DMPK silencing in mammalian cells

Mirtrons are introns that form pre-miRNA hairpins after splicing to produce RNA interference (RNAi) effectors distinct from Drosha-dependent intronic miRNAs. Here we present a design algorithm for artificial mirtrons and demonstrate, for the first time, efficient gene knockdown of myotonic dystrophy protein kinase (DMPK) target sequences in Renilla luciferase 3' UTR and subsequently pathogenic DMPK mRNA, causative of Type I myotonic dystrophy, using artificial mirtrons cloned as eGFP introns. Deep sequencing of artificial mirtrons suggests that functional mature transcripts corresponding to the designed sequence were produced in high abundance. They were further shown to be splicing-dependent, Drosha-independent, and partially dependent on exportin-5, resulting in the precise generation of pre-miRNAs. In a murine myoblast line containing a pathogenic copy of human DMPK with more than 500 CUG repeats, the DMPK artificial mirtron corrected DM1-associated splicing abnormalities of the Serca-1 mRNA, demonstrating the therapeutic potential of mirtron-mediated RNAi. Thus, further development and exploitation of the unique properties of mirtrons will benefit future research and therapeutic RNAi applications as an alternative to conventional RNAi strategies

Development of a non-human primate BCG infection model for the evaluation of candidate tuberculosis vaccines.

The lack of validated immunological correlates of protection makes tuberculosis vaccine development difficult and expensive. Using intradermal bacille Calmette-Guréin (BCG) as a surrogate for aerosol Mycobacterium tuberculosis (M.tb) in a controlled human infection model could facilitate vaccine development, but such a model requires preclinical validation. Non-human primates (NHPs) may provide the best model in which to do this. Cynomolgus and rhesus macaques were infected with BCG by intradermal injection. BCG was quantified from a skin biopsy of the infection site and from draining axillary lymph nodes, by culture on solid agar and quantitative polymerase chain reaction. BCG was detected up to 28 days post-infection, with higher amounts of BCG detected in lymph nodes after high dose compared to standard dose infection. Quantifying BCG from lymph nodes of cynomolgus macaques 14 days post-high dose infection showed a significant reduction in the amount of BCG detected in the BCG-vaccinated compared to BCG-naïve animals. Demonstrating a detectable vaccine effect in the lymph nodes of cynomolgus macaques, which is similar in magnitude to that seen in an aerosol M.tb infection model, provides support for proof-of-concept of an intradermal BCG infection model and evidence to support the further evaluation of a human BCG infection model

Silencing of Parkinson's disease-associated genes with artificial mirtron mimics of miR-1224

Mirtrons are a recently described category of microRNA (miRNA) relying on splicing rather than processing by the microprocessor complex to generate pre-miRNA precursors of the RNA interference (RNAi) pathway. Their discovery and subsequent verification provides important information about a distinct class of miRNA and inherent advantages that could be exploited to silence genes of interest. These include micro-processor-independent biogenesis, pol-II-dependent transcription, accurate species generation and the delivery of multiple artificial mirtrons as introns within a single host transcript. Here we determined the sequence motifs required for correct processing of the mmu-miR-1224 mirtron and incorporated these into artificial mirtrons targeting Parkinson's disease-associated LRRK2 and α-synuclein genes. By incorporating these rules associated with processing and splicing, artificial mirtrons could be designed and made to silence complementary targets either at the mRNA or protein level. We further demonstrate with a LRRK2 targeting artificial mirtron that neuronal-specific silencing can be directed under the control of the human synapsin promoter. Finally, multiple mirtrons were co-delivered within a single host transcript, an eGFP reporter, to allow simultaneous targeting of two or more targets in a combinatorial approach. Thus, the unique characteristics of artificial mirtrons make this an attractive approach for future RNAi applications

The biogenesis and characterization of mammalian microRNAs of mirtron origin

Mirtrons, short hairpin pre-microRNA (miRNA) mimics directly produced by intronic splicing, have recently been identified and experimentally confirmed in invertebrates. While there is evidence to suggest several mammalian miRNAs have mirtron origins, this has yet to be experimentally demonstrated. Here, we characterize the biogenesis of mammalian mirtrons by ectopic expression of splicing-dependent mirtron precursors. The putative mirtrons hsa-miR-877, hsa-miR-1226 and mmu-miR-1224 were designed as introns within eGFP. Correct splicing and function of these sequences as introns was shown through eGFP fluorescence and RT–PCR, while all mirtrons suppressed perfectly complementary luciferase reporter targets to levels similar to that of corresponding independently expressed pre-miRNA controls. Splicing-deficient mutants and disruption of key steps in miRNA biogenesis demonstrated that mirtron-mediated gene knockdown was splicing-dependent, Drosha-independent and had variable dependence on RNAi pathway elements following pre-miRNA formation. The silencing effect of hsa-miR-877 was further demonstrated to be mediated by the generation of short anti-sense RNA species expressed with low abundance. Finally, the mammalian mirtron hsa-miR-877 was shown to reduce mRNA levels of an endogenous transcript containing hsa-miR-877 target sites in neuronal SH-SY5Y cells. This work confirms the mirtron origins of three mammalian miRNAs and suggests that they are a functional class of splicing-dependent miRNAs which are physiologically active

High-potency ligands for DREADD imaging and activation in rodents and monkeys.

Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) are a popular chemogenetic technology for manipulation of neuronal activity in uninstrumented awake animals with potential for human applications as well. The prototypical DREADD agonist clozapine N-oxide (CNO) lacks brain entry and converts to clozapine, making it difficult to apply in basic and translational applications. Here we report the development of two novel DREADD agonists, JHU37152 and JHU37160, and the first dedicated 18F positron emission tomography (PET) DREADD radiotracer, [18F]JHU37107. We show that JHU37152 and JHU37160 exhibit high in vivo DREADD potency. [18F]JHU37107 combined with PET allows for DREADD detection in locally-targeted neurons, and at their long-range projections, enabling noninvasive and longitudinal neuronal projection mapping

Identification of Allele-Specific RNAi Effectors Targeting Genetic Forms of Parkinson's Disease

Parkinson's disease (PD) is a progressive neurological disorder affecting an estimated 5–10 million people worldwide. Recent evidence has implicated several genes that directly cause or increase susceptibility to PD. As well as advancing understanding of the genetic aetiology of PD these findings suggest new ways to modify the disease course, in some cases through genetic manipulation. Here we generated a ‘walk-through’ series of RNA Pol III-expressed shRNAs targeting both the α-synuclein A30P and LRRK2 G2019S PD-associated mutations. Allele-specific discrimination of the α-synuclein A30P mutation was achieved with alignments at position 10, 13 and 14 in two model systems, including a heterozygous model mimicking the disease setting, whilst 5′RACE was used to confirm stated alignments. Discrimination of the most common PD-linked LRRK2 G2019S mutation was assessed in hemizygous dual-luciferase assays and showed that alignment of the mutation opposite position 4 of the antisense species produced robust discrimination of alleles at all time points studied. Discrimination at this position was subsequently confirmed using siRNAs, where up to 10-fold discrimination was seen. The results suggest that RNAi-mediated silencing of PD-associated autosomal dominant genes could be a novel therapeutic approach for the treatment of the relevant clinical cases of PD in future

High-potency ligands for DREADD imaging and activation in rodents and monkeys

Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) are a popular chemogenetic technology for manipulation of neuronal activity in uninstrumented awake animals with potential for human applications as well. The prototypical DREADD agonist clozapine N-oxide (CNO) lacks brain entry and converts to clozapine, making it difficult to apply in basic and translational applications. Here we report the development of two novel DREADD agonists, JHU37152 and JHU37160, and the first dedicated 18F positron emission tomography (PET) DREADD radiotracer, [18F]JHU37107. We show that JHU37152 and JHU37160 exhibit high in vivo DREADD potency. [18F]JHU37107 combined with PET allows for DREADD detection in locally-targeted neurons, and at their long-range projections, enabling noninvasive and longitudinal neuronal projection mapping