MicroRNA‐93‐5p expression in tumor tissue and its tumor suppressor function via targeting programmed death ligand‐1 in colorectal cancer

This work aimed to investigate miR‐93‐5p expression in tumor tissue and its in vitro effects in colorectal cancer (CRC) by targeting programmed death ligand‐1 (PD‐L1). MiR‐93‐5p and PD‐L1 expression was detected in CRC and adjacent normal tissues by quantitative real‐time polymerase chain reaction and immunohistochemistry. The correlation between miR‐93‐5p and PD‐L1 was validated by a dual‐luciferase reporter assay. HCT116 and SW480 cells were divided into blank, miR‐NC, miR‐93‐5p mimics, miR‐93‐5p inhibitor, PD‐L1 small interfering RNA (siRNA) and miR‐93‐5p inhibitor + PD‐L1 siRNA groups, and wound‐healing and transwell assays were performed to detect cell migration and invasion, respectively. Protein expression was measured by western blotting. The secretion of cytokines was detected in the CRC cell/T coculture models. MiR‐93‐5p was downregulated in CRC tissues with upregulated PD‐L1. In PD‐L1‐negative patients, miR‐93‐5p expression was increased compared with that in PD‐L1‐positive patients. MiR‐93‐5p and PD‐L1 expression levels were associated with the tumor differentiation, lymphatic metastasis, TNM, Duke's stage, and prognosis of CRC. PD‐L1 siRNA weakened the migration and invasion abilities via decreased expression of matrix metalloproteinase‐1 (MMP‐1), ‐2, and ‐9, and these effects were abolished by the miR‐93‐5p inhibitor. Additionally, anti‐PD‐L1 upregulated the expressions of interleukin‐2 (IL‐2), tumor necrosis factor‐α (TNF‐α), and interferon γ (IFN‐γ) in the coculture of T cells with CRC cells, but downregulated the expressions of IL‐1β, IL‐10, and TGF‐β. However, these changes were partially reversed by miR‐93‐5p inhibition. miR‐93‐5p is expected to be a novel target for CRC treatment since it decreases the migration and invasion, as well as the immune evasion, of CRC cells via targeting PD‐L1.     

Insight into the bovine milk peptide LPcin‐YK3 selection in the proteolytic system of Lactobacillus species

Antimicrobial peptides are class of small, positively charged peptides known for their broad‐spectrum antimicrobial activity. Antimicrobial activities for most antimicrobial peptides have largely remained elusive, particularly in the lactic acid bacteria. However, recently our investigation using LPcin‐YK3, an antimicrobial peptide from bovine milk, suggests that in vitro antimicrobial activity was reduced over 100‐fold compared with pathogenic bacteria. Additionally, for the structural study of how antimicrobial peptide undergoes its reaction at the proteolytic pathway of lactic acid bacteria based on degradation assay and propidium iodide staining, we performed molecular docking for interaction between oligopeptide‐binding protein A and LPcin‐YK3 peptide. Given that degradation related to the LPcin‐YK3 peptide in lactic acid bacteria proteolytic system, the inhibitory inactivity of LPcin‐YK3 against beneficial lactic acid bacteria strains may be one of the primary pharmacological properties of recombinant peptide discovered in bovine milk. These results provide structural and functional insights into the proteolytic mechanism and possibility as a putative substrate of oligopeptide‐binding protein A in respect of LPcin‐YK3 peptide.     

The copulatory apparatus of the marine gastropod Haminella solitaria (Heterobranchia: Cephalaspidea) and its phylogenetic relevance

The hermaphroditic marine snail species Haminella solitaria was formerly included in the genus Haminoea, but it was recently assigned to the genus Haminella. The copulatory apparatus in H. solitaria was investigated by light and transmission electron microscopy to obtain additional information about this apparatus in cephalaspidean gastropods and to evaluate the taxonomic relevance of its morphofunctional features in the framework of a new phylogenetic tree of the family Haminoeidae. The copulatory apparatus in H. solitaria consisted of the atrium with a muscular wall and papilla, a seminal duct, and a single‐lobed prostate. Epithelial and subepithelial secretory cells were detected in the proximal and middle region of the atrium wall, and a third type of secretory cell occurred in the distal region of the muscular papilla. The seminal duct was lined by ciliated cells and its muscular wall included some vacuolar cells. The prostate in H. solitaria consisted of lateral pouches surrounding a large central lumen that was filled with spermatozoa. A single type of secretory cell intermingled with ciliated cells formed the epithelium of the prostate. A histological comparison between the copulatory apparatus in H. solitaria and Haminoea navicula revealed substantial differences that support the placement of these two species in different genera, as established by recent molecular studies.     

Leaf gall polymorphism and molecular phylogeny of a new Bruggmanniella species (Diptera: Cecidomyiidae: Asphondyliini) associated with Litsea acuminata (Lauraceae) in Taiwan,with ecological comparisons and a species description

Two types of cecidomyiid leaf galls, cup‐shaped and umbrella‐shaped, occur on Litsea acuminata (Lauraceae) in Taiwan. Based on the concept of gall shapes as “extended phenotypes” of gall inducers, these two types could be induced by different gall midge species. However, galls with intermediate shapes between the two types were recently discovered, which implies that possible genetic exchanges occur between the gall inducers of both types. To clarify the taxonomic status of gall midges responsible for the two types of galls on L. acuminata, we undertook taxonomic, molecular phylogenetic and ecological studies. Our findings show that the two gall types are induced by the same Bruggmanniella species and the species is new to science. We describe the species forming this range of galls as Bruggmanniella litseae sp. n. , and compare their geographical distribution, galling position and morphometry. Based on our results, a possible evolutionary scenario of B. litseae sp. n. is discussed.     

Life cycles,phenology and genetic structure of endangered Megacrania tsudai Shiraki (Phasmatodea: Phasmatidae): Male individuals from a geographic parthenogenesis species

Megacrania tsudai, a peripherally distributed member of Megacrania, requires conservation in Taiwan; it has limited distribution in Taiwan and its eastern offshore islands. It feeds on screw pines (Pandanus odoratissimus) in nature and has demonstrated a specific defensive mechanism involving actinidine secretion from the prothoracic gland. However, details of its distribution area, life cycle and developmental phenology remain largely unknown. In this study, a field survey and review of published works revealed M. tsudai distribution in coastal zones and along river shores near estuaries. At room temperature, the egg period was 128 days. The development of the first to sixth instars required 17, 26, 27, 26, 34 and 43 days, respectively, on average; and a generation cycle required approximately 204 days. The phenology of the mesonotal granules was recorded. Moreover, genetic analysis of the mitochondrial cytochrome oxidase I (COI), 16S ribosomal DNA (16S rDNA) and the nuclear ribosomal spacer indicated the occurrence of genetic drift. Therefore, the rearing procedures proposed in this study for the primary and last instars of M. tsudai can facilitate its conservation. Megacrania tsudai was previously recorded as parthenogenetic; however, two male individuals were fostered unexpectedly. The male body length was 91 mm, which is shorter than the female length (120 mm). During mating, the male climbs onto the female's back and protrudes its genitalia downward. Geographical parthenogenesis is likely the reproductive strategy among peripheral M. tsudai; however, the rarely found M. tsudai male could be an intermediate link of reproductive strategy in the transition from tychoparthenogenesis to parthenogenesis.     

Rainfall manipulation experiments as simulated by terrestrial biosphere models: Where do we stand?

Changes in rainfall amounts and patterns have been observed and are expected to continue in the near future with potentially significant ecological and societal consequences. Modelling vegetation responses to changes in rainfall is thus crucial to project water and carbon cycles in the future. In this study, we present the results of a new model‐data intercomparison project, where we tested the ability of 10 terrestrial biosphere models to reproduce the observed sensitivity of ecosystem productivity to rainfall changes at 10 sites across the globe, in nine of which, rainfall exclusion and/or irrigation experiments had been performed. The key results are as follows: (a) Inter‐model variation is generally large and model agreement varies with timescales. In severely water‐limited sites, models only agree on the interannual variability of evapotranspiration and to a smaller extent on gross primary productivity. In more mesic sites, model agreement for both water and carbon fluxes is typically higher on fine (daily–monthly) timescales and reduces on longer (seasonal–annual) scales. (b) Models on average overestimate the relationship between ecosystem productivity and mean rainfall amounts across sites (in space) and have a low capacity in reproducing the temporal (interannual) sensitivity of vegetation productivity to annual rainfall at a given site, even though observation uncertainty is comparable to inter‐model variability. (c) Most models reproduced the sign of the observed patterns in productivity changes in rainfall manipulation experiments but had a low capacity in reproducing the observed magnitude of productivity changes. Models better reproduced the observed productivity responses due to rainfall exclusion than addition. (d) All models attribute ecosystem productivity changes to the intensity of vegetation stress and peak leaf area, whereas the impact of the change in growing season length is negligible. The relative contribution of the peak leaf area and vegetation stress intensity was highly variable among models.     

Paradise lost: End‐of‐century warming and acidification under business‐as‐usual emissions have severe consequences for symbiotic corals

Despite recent efforts to curtail greenhouse gas emissions, current global emission trajectories are still following the business‐as‐usual representative concentration pathway (RCP) 8.5 emission pathway. The resulting ocean warming and acidification have transformative impacts on coral reef ecosystems, detrimentally affecting coral physiology and health, and these impacts are predicted to worsen in the near future. In this study, we kept fragments of the symbiotic corals Acropora intermedia (thermally sensitive) and Porites lobata (thermally tolerant) for 7 weeks under an orthogonal design of predicted end‐of‐century RCP8.5 conditions for temperature and pCO₂ (3.5°C and 570 ppm above present‐day, respectively) to unravel how temperature and acidification, individually or interactively, influence metabolic and physiological performance. Our results pinpoint thermal stress as the dominant driver of deteriorating health in both species because of its propensity to destabilize coral–dinoflagellate symbiosis (bleaching). Acidification had no influence on metabolism but had a significant negative effect on skeleton growth, particularly when photosynthesis was absent such as in bleached corals or under dark conditions. Total loss of photosynthesis after bleaching caused an exhaustion of protein and lipid stores and collapse of calcification that ultimately led to A. intermedia mortality. Despite complete loss of symbionts from its tissue, P. lobata maintained small amounts of photosynthesis and experienced a weaker decline in lipid and protein reserves that presumably contributed to higher survival of this species. Our results indicate that ocean warming and acidification under business‐as‐usual CO₂ emission scenarios will likely extirpate thermally sensitive coral species before the end of the century, while slowing the recovery of more thermally tolerant species from increasingly severe mass coral bleaching and mortality. This could ultimately lead to the gradual disappearance of tropical coral reefs globally, and a shift on surviving reefs to only the most resilient coral species.     

Multiple trade‐offs regulate the effects of woody plant removal on biodiversity and ecosystem functions in global rangelands

Woody plant encroachment is a major land management issue. Woody removal often aims to restore the original grassy ecosystem, but few studies have assessed the role of woody removal on ecosystem functions and biodiversity at global scales. We collected data from 140 global studies and evaluated how different woody plant removal methods affected biodiversity (plant and animal diversity) and ecosystem functions (plant production, hydrological function, soil carbon) across global rangelands. Our results indicate that the impact of removal is strongly context dependent, varying with the specific response variable, removal method, and traits of the target species. Over all treatments, woody plant removal increased grass biomass and total groundstorey diversity. Physical and chemical removal methods increased grass biomass and total groundstorey biomass (i.e., non‐woody plants, including grass biomass), but burning reduced animal diversity. The impact of different treatment methods declined with time since removal, particularly for total groundstorey biomass. Removing pyramid‐shaped woody plants increased total groundstorey biomass and hydrological function but reduced total groundstorey diversity. Environmental context (e.g., aridity and soil texture) indirectly controlled the effect of removal on biomass and biodiversity by influencing plant traits such as plant shape, allelopathic, or roots types. Our study demonstrates that a one‐size‐fits‐all approach to woody plant removal is not appropriate, and that consideration of woody plant identity, removal method, and environmental context is critical for optimizing removal outcomes. Applying this knowledge is fundamental for maintaining diverse and functional rangeland ecosystems as we move toward a drier and more variable climate.