Biology subjects

Yang, S.-Y.

Publications and source records attributed to Yang, S.-Y..

6 recordsLinked to original sources

bioRxiv2026

Systematic analysis reveals an Mln1-dependent trade-off between metabolic flexibility and thermotolerance in Cryptococcus neoformans

During infection, fungal pathogens must adapt to multiple environmental challenges, including changes in temperature, nutrient availability, and immune stress. Although transcriptional regulators are central to these adaptations, how individual regulators contribute to distinct environmental responses and how these responses are functionally interconnected remain poorly understood. Here, we investigated the functions of infection-associated transcription factors under distinct host-relevant conditions in Cryptococcus neoformans. Integrating in vivo expression profiling with infectivity data from signature-tagged mutagenesis, we prioritized 24 transcription factors, 12 of which were induced under host-mimicking conditions. Initial functional analyses revealed distinct roles for these transcription factors in adaptation to temperature, carbon, and nitrogen availability. Further characterization of Mln1, a fungal basic helix-loop-helix transcription factor, uncovered an unexpected connection between carbon source adaptation and thermotolerance. Mig1-dependent repression limited MLN1 expression in the presence of glucose, whereas Mln1 accumulated in the nucleus in the presence of trehalose or ethanol, but not glucose. Loss of MLN1 impaired carbon-starvation gene expression and growth on non-preferred carbon sources, particularly trehalose. Conversely, mln1{Delta} cells accumulated more intracellular trehalose and exhibited enhanced thermotolerance, yet showed reduced melanization, titan cell formation, virulence in Drosophila, and brain fungal burden in mice. Together, these results suggest that Mln1 contributes to metabolic flexibility and fungal virulence while differentially influencing thermotolerance. More broadly, these findings highlight a potential physiological trade-off between nutrient utilization and stress resistance, suggesting that these adaptive processes may be interconnected in fungal pathogens.

microbiology↗

bioRxiv2024

Salinity impacted microbial carbonate precipitation mechanisms of modern microbialites in peritidal zone

Microbialites, ancient records of microbial activity, serve as significant indicators of environmental change. This study examined microbialites from the peritidal zone of three tide pools at Fongchueisha, Hengchun, Taiwan, to investigate the impact of salinity on microbial community composition and carbonate precipitation mechanisms. Microbial samples were collected across varying salinity gradients over multiple timepoints and analyzed using next-generation sequencing of bacterial 16S and eukaryotic 18S rRNA genes. Our findings reveal that the microbial communities in higher salinity environments exhibited significant shifts, with increased relative abundance of ureolytic bacteria and ammonifying microorganisms, such as Myxococcota and Actinobacteriota. This suggests the presence of diverse microbial carbonate precipitation mechanisms beyond photosynthesis, including ureolysis and ammonification. Furthermore, our results show that changes in the composition of cyanobacteria and diatoms were influenced by salinity, with heterocystous cyanobacteria (e.g., Nostocales) dominating low-salinity environments, and non-heterocystous cyanobacteria (e.g., Synechococcales) prevailing in higher salinity environments. Functional predictions reveal that microbial communities in high-salinity environments were enriched in anaerobic metabolic pathways, including pyruvate fermentation and the urea cycle. These findings highlight the significant role of salinity in influencing microbial composition and metabolic pathways, shaping carbonate precipitation processes in microbialites. ImportanceThe study focuses on the impact of environmental salinity on microbial community composition and carbonate precipitation mechanisms within modern microbialites, based on an analysis of samples from three tide pools with different salinity levels collected at five time points throughout the year. Using next-generation sequencing of bacterial 16S and eukaryotic 18S rRNA genes, we identified key shifts in microbial communities along salinity gradients and explored diverse microbial processes involved in carbonate precipitation. This work enhances our understanding of microbial ecosystems within modern microbialites and their response to environmental changes. Additionally, our study provides insight into ancient biogeochemical processes, with implications for interpreting microbial metabolism in carbonate precipitation across different salinity regimes.

microbiology↗

bioRxiv2024

Fast exploration is coupled with a less choosy but more reactive learning style in a generalist predator

The hypothesis of slow-fast syndromes predicts a correspondence between personality type and learning style; fast explorers would have a more proactive (fast but inflexible) learning style and slow explorers would be more reactive (slow but flexible) learners. Empirical evidence for this personality-cognition coupling remains inconclusive and heavily biased towards birds. Moreover, most studies did not examine the personality-cognition correlation when the cognitive task is discerning food quality, a scenario directly related to energy acquisition that underpins the evolution of slow-fast syndromes. In this study, we examined the exploration-cognition correlation in the context of avoidance learning in an opportunistic predator - the common sun skink Eutropis multifasciata. We quantified exploration tendencies of individuals in an unfamiliar environment and compared foraging behaviours when lizards associated prey colour and quality during the initial learning trials and subsequent reverse learning trials, where the prey colour-taste combinations were switched. We found that fast explorers were less choosy but more reactive foragers, whereas slow explorers exhibited the opposite learning style. Interestingly, there was no evidence for a learning speed-flexibility trade-off. Our findings are in contrast with conventional predictions and suggest that the two types of exploration-cognition coupling could be different viable responses to fast-changing environmental predictability.

animal behavior and cognition↗

bioRxiv2023

Successive responses of three coral holobiont components (coral hosts, symbiotic algae, and bacteria) to daily temperature fluctuations

Coral reef ecosystems support over a quarter of the worlds marine life and play important ecological and economic roles. However, the increasingly severe weather events associated with ocean warming and climate change are believed to be rapidly altering the functions of coral reefs and their ecosystems. Corals and their associated microbiota form a "holobiont," which includes symbiotic algae and other associated microbiota dominated by bacteria. These microbiota have a direct relationship with the health of the coral host. Their composition is influenced by various environmental factors, such as increasing sea water temperatures. Previous studies of the effects of temperature changes on coral physiology and associated bacterial communities have been conducted based on stable water temperatures set by mean temperatures, or by slowly increasing/decreasing temperatures. However, the daily temperature fluctuations that corals experience in nature are not stable. Rather, there may be significant differences of up to 6{degrees}C in a single day. The current understanding of the effects of large daily temperature fluctuations on coral and associated bacterial community dynamics is limited. Hence, in this study, we conducted a four-week tank experiment using different large daily temperature fluctuations accompanied by continuous warming conditions to investigate the effects on two common reef-building corals, Stylophora pistillata and Pocillopora acuta, in Taiwan. During the experiment, the activity of coral host catalase was measured, the photosynthetic ability of symbiotic algae was recorded, and the variation in bacterial communities was analyzed using the V6-V8 region of 16S rDNA. According to the results, different parts of the holobionts of different coral species exhibited varying response rates to the continuous warming conditions and diurnal temperature fluctuations. Additionally, it was found that diurnal temperature fluctuations may mitigate the heat stress on the host and reduce the changes in bacterial response to warming. Furthermore, the holobionts of different coral species may adopt different adaptation and survival strategies in response to diurnal temperature fluctuations and warming. Finally, based on the response of these two coral species under the conditions of diurnal temperature fluctuations and continuous warming, Acinetobacter and Rhodobacteraceae were identified as potential indicator coral-associated bacteria. This is the first study to investigate the tripartite dynamic response of coral, symbiotic algae and bacteria to daily temperature fluctuations.

microbiology↗

bioRxiv2021

DEPDC1/ EEF1A1 complex promotes the progression of human osteosarcoma via downregulation of FOXO3a

There are currently lack of effective therapeutic strategies for osteosarcoma, primarily due to insufficient understanding of the underlying mechanisms of the tumor cells. This study deciphers a potentially critical interplay of DEPDC1-EEF1A1-FOXO3a axis during the osteosarcoma progression. Bioinformatics analysis of documented 25,035 genes for differentially expressed genes were accompanied by transcriptional and translational examinations of clinical osteosarcoma specimens and osteosarcoma cell lines to assess the roles and interactions of DEP domain-containing 1 (DEPDC1), Elongation Factor 1-alpha 1 (EEF1A1), and FOXO3a in the tumor cells proliferation and prognosis. Gene expression profile analysis and clinical tests revealed highly expressed DEPDC1 in human osteosarcoma cells and tumor tissues. Vector-mediated silence of DEPDC1 resulted in halted osteosarcoma cell proliferation, promoted apoptosis, and ceased tumor metastasis. Immunoprecipitation assay confirmed that EEF1A1 directly bind to DEPDC1 protein through three binding regions. Further, DEPDC1/EEF1A1 complex significantly decreased the expression of FOXO3a at transcription and translation levels, which subsequently promoted the proliferation of osteosarcoma cells and tumor metastasis. Correlation studies exhibited that overexpression of DEPDC1/EEF1A1 complex in the clinical specimens negatively correlated with the patient survival rate. In conclusion, DEPDC1-EEF1A1-FOXO3a axis plays as a critical pathway that regulates the progression and prognosis of osteosarcoma.

cell biology↗

bioRxiv2019

Pluripotent Stem Cells Can Be Isolated from Human Peripheral Nerves after in vitro BMP-2 Stimulation

We have recently identified a population of cells within the peripheral nerves of adult mice that can respond to BMP-2 exposure or physical injury to rapidly proliferate. More importantly, these cells exhibited embryonic differentiation potentials that could be induced into osteoblastic and endothelial cells in vitro. The current study examined human nerve specimens to compare and characterize the cells after BMP-2 stimulation. Fresh pieces of human nerve tissue were minced and treated with either BMP-2 (750ng/ml) or vehicle for 12 hours at 37{degrees}C, before digested in 0.2% collagenase and 0.05% trypsin-EDTA. Isolated cells were cultured in restrictive stem cell medium. Significantly more cells were obtained from the nerve pieces with BMP-2 treatment in comparison with the non-treated controls. Cell colonies were starting to form at day 3. Expressions of the 4 transcription factors Klf4, c-Myc, Sox2 and Oct4 were confirmed at both transcriptional and translational levels. The cells can be maintained in the stem cell culture medium for at least 6 weeks without changing morphologies. When the cells were switched to fibroblast growth medium, dispersed spindle-shaped cells were noted and became fibroblast activated protein- (FAP) positive following immunocytochemistry staining. The data suggested that human peripheral nerve tissue also contain a population of cells that can respond to BMP-2 and express all four transcription factors KLF4, Sox2, cMyc, and Oct4. These cells are capable to differentiate into FAP-positive fibroblasts. It is proposed that these cells are possibly at the core of a previously unknown natural mechanism for healing injury.

cell biology↗