In vivo Pooled Screening: A Scalable Tool to Study the Complexity of Aging and Age-Related Disease

Biological aging, and the diseases of aging, occur in a complex in vivo environment, driven by multiple interacting processes. A convergence of recently developed technologies has enabled in vivo pooled screening: direct administration of a library of different perturbations to a living animal, with a subsequent readout that distinguishes the identity of each perturbation and its effect on individual cells within the animal. Such screens hold promise for efficiently applying functional genomics to aging processes in the full richness of the in vivo setting. In this review, we describe the technologies behind in vivo pooled screening, including a range of options for delivery, perturbation and readout methods, and outline their potential application to aging and age-related disease. We then suggest how in vivo pooled screening, together with emerging innovations in each of its technological underpinnings, could be extended to shed light on key open questions in aging biology, including the mechanisms and limits of epigenetic reprogramming and identifying cellular mediators of systemic signals in aging.

Deploying photons for communication within neuronal networks

Deficiencies in neurotransmission lead to neurological disorders or misinterpretation of perceived threats. To restore defects in cellular communication, we developed a synthetic, photon-assisted synaptic transmission (PhAST) system. PhAST is based on luciferases and channelrhodopsins that enable the transmission of a neuronal state across space, using photons as neurotransmitters. We demonstrate the ability to overcome synaptic barriers and rescue the behavioral deficit of a genetically engineered glutamate mutant with conditional, Ca2+-triggered photon emission between two cognate neurons of the Caenorhabditis elegans nociceptive avoidance circuit.We also deploy these ingredients for asynaptic transmission between two unrelated cells in a sexually dimorphic neuronal network. Functional PhAST could sensitize otherwise poorly responsive males to touch and hence expand the behavioral repertoire. Our study, thus, establishes a powerful framework for complex photon-based communication between neurons in a living animal, that can readily be expanded to synthetic neuronal networks, organoids or non-invasive brain-machine interfaces.

Porcine Circovirus 3a Field Strains in Free-Living Wild Boars in Paraná State, Brazil

Porcine circovirus 3 (PCV-3) was identified in domestic pigs worldwide. Although PCV-3 has also been detected in wild boars, information regarding its circulation in this free-living animal species is scarce. To investigate PCV-3 occurrence in free-living wild boars in Brazil, 70 serum samples collected between January 2017 and June 2019 in Paraná state, Brazil were analyzed by PCR assay. Amplicons measuring 330 bp in length were amplified in seven (10.0%) of the serum samples and confirmed to be PCV3-specific by nucleotide (nt) sequencing. As the amplified products from the serum samples yielded only intermediate levels of viral DNA, lung samples from the seven PCR-positive wild boars were also evaluated by PCR. Of these samples, five lung samples were positive and provided high levels of viral DNA. The three lung samples that presented the highest levels of viral DNA were selected for amplification and sequencing of the whole PCV-3 genome. The three full-length sequences obtained were grouped in PCV-3 clade “a”, and the sequences exhibited 100% nucleotide similarity among them. The PCV-3 field strains of this study showed nucleotide and amino acid similarities of 98.5–99.8% and 98.8–100%, respectively, with whole-genome PCV-3 sequences from around the world.

Law and the Laboratory: The British Vivisection Inspectorate in the 1890s

The 1876 British Cruelty to Animals Act introduced an unprecedented administrative system to supervise any experiment “calculated to give pain” to a living animal. The act, which was in force for a hundred years, established a tight system of control over animal experimentation, including a small, but vigorous, inspectorate. This article explores the relations between bureaucracy and the production of knowledge through the correspondences, memos, and notes taken by two principal inspectors under the act. The inspectors belonged to the worlds of both law and science. Coming from within the scientific profession, their close ties to medical social circles not only evoked critique but also helped them fulfill their tasks and gain access to research laboratories. Archival records examined here for the first time show that, although the inspectors downplayed animals’ pain in physiological laboratories, the inspectorate played an important role in shaping the experimental space and practice, thus facilitating the production of “ethical scientific facts.” The inspectors’ work modeled the new legal regime of animal experimentation regulation, making them indispensable agents in the act’s coproduction of knowledge and public order.

THE CHANGING MEANINGS OF THE MATERIAL IN POOR ART AND THE USE OF LIVE ANIMALS

The Arte Povera movement emerged as a reaction to the mainstreams in Europe in the second half of the 1960s. Poor art has created a new sense of time by focusing on what is here and now in the trilogy of past, present, future. In this perception there are roots of destructiveness. The main issue of poor art, which places the concept of time at the center, is the problem of temporality and permanence. It takes place within itself. The transformation of the artwork in the process has shaken the permanence of the work; therefore, the uniqueness of the work and the test of writing accordingly began to be questioned again. This research is focused on the ongoing arrangements of the leading representatives of Poor art, Jannis Kounellis and Pier Paolo Calzolari, who used an alive dog or horse as an art object. In this context, the state of the art work will be revealed through the changing print, temporality and permanence of the work. Semantic analysis of the works of these artists will be made through the context of human, animal and art. Keywords: Poor Art, Living Animal, Artwork, Temporality-permanence problem

Life Sentence: Mollusc Prisoner in Cretaceous Brachiopod Reconstructed in 3D. First Evidence for the Co-Existence of A Mollusc Inside a Living Animal

A tiny shell (7 mm length) of a juvenile Mollusc (supposed gastropod) was discovered enclosed within the packstone filled shell of a terebratellidine brachiopod (Zittelina hofmanni Bujtor and Vörös, 2020) from the Lower Cretaceous Apátvarasd Limestone Formation of Zengővárkony (Mecsek Mountains, South Hungary). Serial sectioning of the brachiopod shell revealed that in addition to the brachidium, a different and unusual shelly structure was preserved inside the brachiopod shell. 2D serial sections were digitalized and fed into Free-D imaging software to generate a 3D reconstruction of the entombed fossil, which is supposed a juvenile gastropod. Consideration of the emplacement, dimensions, and orientation of the shell suggests that it entered the cavity of the living brachiopod shell as an egg or larva and was trapped. Further analysis of both fossils suggests that the two animals lived and developed beside each other for a longer period: the brachiopod crus is less developed and slightly deformed on the gastropod side with the gastropod placed parallel to the crura and the lateral wall of the brachiopod. This example suggests that shells of brachiopods may have provided sheltered microhabitats for benthic micro- and macrofossils not only after the death but even during the life of the host brachiopod. This is the first evidence from the fossil record for the co-existence of a living Mollusc inside the shell of a living brachiopod. This work illustrates how general purpose 3D modelling software initially developed in other disciplines may provide new insights in the wide field of geosciences.