A Private Tree By-Law’s Contribution to Maintaining a Diverse Urban Forest: Exploring Homeowners’ Replanting Compliance and the Role of Construction Activities in Toronto, Canada

Many municipalities are working to protect and grow their urban forest, including adopting private tree regulations. Such regulations typically require property-owners to apply for a permit to remove trees and, if the permit is granted, plant replacement trees. Even with such regulations, many private trees are removed each year, particularly on residential property. Property-level construction activity, including expanding building footprints, replacing an older home with a new one, and increasing hardscaping, is emerging as a key driver of residential tree loss. This study addresses whether homeowners who receive a permit to remove one or more trees comply with the requirement to plant replacement trees to better understand the effect of private tree regulation. We explore this question through a written survey of homeowners who received a tree removal permit and site visits in Toronto (Ontario, Canada). While 70% of all survey participants planted the required replacement trees 2 to 3 years after receiving the permit, only 54% of homeowners whose permit was associated with construction planted. Additionally, most replacement trees were in good health but were dominated by a few genera. We also found significant differences in replacement planting and tree survival across the city’s 4 management districts. This study highlights that if resources supporting private tree regulations are limited, tree permits associated with construction should be prioritized for follow-up. Additionally, guidance about diverse species to plant should be communicated to ensure that private tree regulations are supporting the long-term protection of the urban forest.

Polyphosphate affects cytoplasmic and chromosomal dynamics in nitrogen-starved Pseudomonas aeruginosa

Polyphosphate (polyP) synthesis is a ubiquitous stress and starvation response in bacteria. In diverse species, mutants unable to make polyP have a wide variety of physiological defects, but the mechanisms by which this simple polyanion exerts its effects remain unclear. One possibility is that polyP′s many functions stem from global effects on the biophysical properties of the cell. We characterize the effect of polyphosphate on cytoplasmic mobility under nitrogen-starvation conditions in the opportunistic pathogen Pseudomonas aeruginosa. Using fluorescence microscopy and particle tracking, we characterize the motion of chromosomal loci and free tracer particles in the cytoplasm. In the absence of polyP and upon starvation, we observe an increase in mobility both for chromosomal loci and for tracer particles. Tracer particles reveal that polyP also modulates the partitioning between a ′more mobile′ and a ′less mobile′ population: small particles in cells unable to make polyP are more likely to be ′mobile′ and explore more of the cytoplasm, particularly during starvation. We speculate that this larger freedom of motion may be a consequence of nucleoid decompaction, which we also observe in starved cells deficient in polyP. Our observations suggest that polyP limits cytoplasmic mobility and accessibility during nitrogen starvation, which may help to explain the pleiotropic phenotypes observed in the absence of polyP.

Evolutionary footprints of a cold relic in a rapidly warming world

With accelerating global warming, understanding the evolutionary dynamics of plant adaptation to environmental change is increasingly urgent. Here we reveal the enigmatic history of the genus Cochlearia (Brassicaceae), a Pleistocene relic that originated from a drought-adapted Mediterranean sister genus during the Miocene. Cochlearia rapidly diversified and adapted to circum-Arctic regions and other cold-characterized habitat types during the Pleistocene. This sudden change in ecological preferences was accompanied by a highly complex, reticulate polyploid evolution, which was apparently triggered by the impact of repeated Pleistocene glaciation cycles. Our results illustrate that two early diversified arctic-alpine diploid gene pools contributed differently to the evolution of this young polyploid genus now captured in a cold-adapted niche. Metabolomics revealed central carbon metabolism responses to cold in diverse species and ecotypes, likely due to continuous connections to cold habitats that may have facilitated widespread adaptation to alpine and subalpine habitats, and which we speculate were coopted from existing drought adaptations. Given the growing scientific interest in adaptive evolution of temperature-related traits, our results provide much-needed taxonomic and phylogenomic resolution of a model system as well as first insights into the origins of its adaptation to cold.

Efficiency fosters cumulative culture across species

Recent studies in several taxa have demonstrated that animal culture can evolve to become more efficient in various contexts ranging from tool use to route learning and migration. Under recent definitions, such increases in efficiency might satisfy the core criteria of cumulative cultural evolution (CCE). However, there is not yet a satisfying consensus on the precise definition of efficiency, CCE or the link between efficiency and more complex, extended forms of CCE considered uniquely human. To bring clarity to this wider discussion of CCE, we develop the concept of efficiency by (i) reviewing recent potential evidence for CCE in animals, and (ii) clarifying a useful definition of efficiency by synthesizing perspectives found within the literature, including animal studies and the wider iterated learning literature. Finally, (iii) we discuss what factors might impinge on the informational bottleneck of social transmission, and argue that this provides pressure for learnable behaviours across species. We conclude that framing CCE in terms of efficiency casts complexity in a new light, as learnable behaviours are a requirement for the evolution of complexity. Understanding how efficiency greases the ratchet of cumulative culture provides a better appreciation of how similar cultural evolution can be between taxonomically diverse species—a case for continuity across the animal kingdom. This article is part of a discussion meeting issue ‘The emergence of collective knowledge and cumulative culture in animals, humans and machines’.

CD4+ and CD8+ regulatory T cells characterization in the rat using a unique transgenic Foxp3-EGFP model.

Background: CD4+ and CD8+ regulatory T cells (Treg) in diverse species include different subsets from different origins. In all species, CD8+ Treg have been poorly characterized. CD4+ and CD8+ Treg in rats have only partially been characterized and there is no rat model in which FOXP3+ Treg are genetically tagged. Results: We generated a rat transgenic line using the CRISPR/Cas9 system in which EGFP was inserted in frame on the 3 end of the Foxp3 gene using a 2A self-cleaving peptide. EGFP was exclusively expressed by CD4+ and CD8+ T cells in similar proportion as observed with anti-FOXP3 antibodies. CD4+EGFP+ Treg were 5-10 times more frequent than CD8+EGFP+ Treg. CD4+ and CD8+ EGFP+ Treg expressed both the CD25highCD127lowCD45RClow/- markers. The suppressive activity of CD4+ and CD8+ Treg was largely confined to EGFP+ cells. RNAseq analyses showed similarities but also differences among CD4+ and CD8+ EGFP+ cells and provided the first description of the natural FOXP3+ CD8+ Treg transcriptome. In vitro culture of CD4+ and CD8+ EGFP- cells with TGFbeta and IL-2 resulted in the induction of EGFP+ Treg. Preferential expansion of CD4+ and CD8+ EGFP+ Treg could be detected upon in vivo administration of a low dose of IL-2. Conclusions: This new and unique Foxp3-EGFP rat line constitutes a useful model to identify and isolate viable natural and induced CD4+ and CD8+ Treg. Additionally, it allows to identify new molecules expressed in CD8+ Treg that may allow to better define their phenotype and function not only in rats but also in other species.

Convergence of undulatory swimming kinematics across a diversity of fishes

Fishes exhibit an astounding diversity of locomotor behaviors from classic swimming with their body and fins to jumping, flying, walking, and burrowing. Fishes that use their body and caudal fin (BCF) during undulatory swimming have been traditionally divided into modes based on the length of the propulsive body wave and the ratio of head:tail oscillation amplitude: anguilliform, subcarangiform, carangiform, and thunniform. This classification was first proposed based on key morphological traits, such as body stiffness and elongation, to group fishes based on their expected swimming mechanics. Here, we present a comparative study of 44 diverse species quantifying the kinematics and morphology of BCF-swimming fishes. Our results reveal that most species we studied share similar oscillation amplitude during steady locomotion that can be modeled using a second-degree order polynomial. The length of the propulsive body wave was shorter for species classified as anguilliform and longer for those classified as thunniform, although substantial variability existed both within and among species. Moreover, there was no decrease in head:tail amplitude from the anguilliform to thunniform mode of locomotion as we expected from the traditional classification. While the expected swimming modes correlated with morphological traits, they did not accurately represent the kinematics of BCF locomotion. These results indicate that even fish species differing as substantially in morphology as tuna and eel exhibit statistically similar two-dimensional midline kinematics and point toward unifying locomotor hydrodynamic mechanisms that can serve as the basis for understanding aquatic locomotion and controlling biomimetic aquatic robots.

Impact of Caloric Restriction on Molecular and Functional Networks in Rhesus Monkeys

Caloric restriction (CR) delays aging and the onset of age-related disease in diverse species. Several diseases of aging including diabetes, cancer, and neurodegeneration, have an established metabolic component. Although the mechanisms of CR remain unknown, numerous factors implicated in longevity regulation by CR converge on regulation of metabolism. The reprograming of metabolism with CR is tissue specific, but mitochondrial activation and changes in redox metabolism are among the shared features. Changes in non-coding miRNA and in processing of transcripts are contributing mechanisms in integrating metabolic and growth pathways. Our studies in simple cell culture shows that small changes in metabolic status can precipitate large-scale multi-modal functional changes across cellular processes. We propose that modest failures in metabolic integrity with age broadly impact homeostasis and adaptation, creating shared vulnerability to diseases and conditions despite differences in their etiology, and that CR harnesses this same axis to promote health and enhanced longevity.

Neuroendocrine Control of Reproduction in Teleost Fish: Concepts and Controversies

During the teleost radiation, extensive development of the direct innervation mode of hypothalamo-pituitary communication was accompanied by loss of the median eminence typical of mammals. Cells secreting follicle-stimulating hormone and luteinizing hormone cells are directly innervated, distinct populations in the anterior pituitary. So far, ∼20 stimulatory and ∼10 inhibitory neuropeptides, 3 amines, and 3 amino acid neurotransmitters are implicated in the control of reproduction. Positive and negative sex steroid feedback loops operate in both sexes. Gene mutation models in zebrafish and medaka now challenge our general understanding of vertebrate neuropeptidergic control. New reproductive neuropeptides are emerging. These include but are not limited to nesfatin 1, neurokinin B, and the secretoneurins. A generalized model for the neuroendocrine control of reproduction is proposed. Hopefully, this will serve as a research framework on diverse species to help explain the evolution of neuroendocrine control and lead to the discovery of new hormones with novel applications. Expected final online publication date for the Annual Review of Animal Biosciences, Volume 10 is February 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Primer registro de Acanthoscelides obtectus (Coleoptera: Chrysomelidae: Bruchinae) en Senna multiglandulosa (Fabaceae) de la región andina central del Perú

Acanthoscelides obtectus (Say, 1831) (Coleoptera: Chrysomelidae: Bruchinae) es unescarabajo de distribución cosmopolita que ocasiona graves daños a diversas especies de la familia Fabaceae. Este trabajo es el primer reporte de su infestación en arbustos de Senna multiglandulosa (Jacq.) H.S. Irwin & Barneby, 1982 (Fabaceae) en la zona andina central del Perú. Se describe la morfología de los estados biológicos de A. obtectus y las perforaciones que realizaron en legumbres infestadas colectadas en tres lugares del Valle del Mantaro de enero a diciembre 2018. Se midió la longitud total (L) y ancho (A) de los huevos, larvas, pupas y adultos de A. obtectus, así como el diámetro (D) de las perforaciones en vainas y semilla de S. multiglandulosa. Los resultados mostraron diferencias significativas en los tamaños de cada uno de los estadios (p < 0,001) y sus perforaciones en las legumbres (p < 0,001), afectan especialmente las semillas de S. multiglandulosa, por lo cual se constituye en un problema sanitario muy severo en la planta estudiada. Acanthoscelides obtectus (Say, 1831) (Coleoptera: Chrysomelidae: Bruchinae) is a beetle with a cosmopolitan distribution that causes severe damages to diverse species of the Fabaceae family. This is the first report of its infestation on Senna multiglandulosa (Jacq.) H.S. Irwin & Barneby, 1982 (Fabaceae) bushes in the central Andean region of Peru. The morphology of the biological stages of A. obtectus and the perforations they made on infested legumes collected in three sites of Mantaro Valley from January to December 2018 are described. The total length (L) and width (W) of eggs, larvae, pupae, and adults of A. obtectus and the diameter (D) of the perforations on the pods and seeds of S. multiglandulosa were measured. The results showed significant differences in the size of each stage (p < 0.001) and their perforations on legumes (p < 0.001), affecting mainly the seeds of S. multiglandulosa, constituting a severe health problem for the studied plant.

Evolutionary Conservation of Systemic and Reversible Amyloid Aggregation

In response to environmental stress, human cells have been shown to form reversible amyloid aggregates within the nucleus, termed amyloid bodies (A-bodies). These protective physiological structures share many of the biophysical characteristics associated with the pathological amyloids found in Alzheimer's and Parkinson's disease. Here, we show that A-bodies are evolutionarily conserved across the eukaryotic domain, with their detection in D. melanogaster and S. cerevisiae marking the first examples of these functional amyloids being induced outside of a cultured cell setting. The conditions triggering amyloidogenesis varied significantly among the species tested, with results indicating that A-body formation is a severe, but sub-lethal, stress response pathway that is tailored to an organism's environmental norms. RNA-sequencing analyses demonstrate that the regulatory low-complexity long non-coding RNAs that drive A-body aggregation are both conserved and essential in human, mouse, and chicken cells. Thus, the identification of these natural and reversible functional amyloids in a variety of evolutionarily diverse species, highlights the physiological significance of this protein conformation and will be informative in advancing our understanding of both functional and pathological amyloid aggregation events.