Search bioRxiv⌕ Search

Biology subjects

Hui, B.

Publications and source records attributed to Hui, B..

5 recordsLinked to original sources

A Synergistic Terpenoid-Phenolic Defense Network Confers Resistance to Dendrolimus superans in Hybrid Larch

To elucidate the resistance of hybrid larch (Larix spp.) clones to Dendrolimus superans and their chemical defense mechanisms, 46 clones were subjected to field feeding-infestation experiments. Insect resistance was comprehensively evaluated by the membership function method from three perspectives: insect weight change, frass weight and defoliation rate (damage consequences); pre- and post-infestation physiological indices (constitutive and induced resistance). High- and low-resistance materials screened from each perspective were further analyzed by widely targeted LC-MS metabolomics. The three damage indices differed highly significantly among clones (P<0.01) and were positively correlated, indicating abundant genetic variation in resistance. Clones such as -30-C, -35-A and -21-A showed strong overall resistance, whereas -28-E and -20-A showed high constitutive and induced resistance. Defence enzyme activities (POD, SOD, CAT, PPO and PAL) correlated closely with secondary metabolites (total phenolics, tannins and total flavonoids) and nutrients, and rose synergistically after feeding, reflecting synergy between constitutive and induced resistance. In total, 3,577 metabolites were identified, predominantly terpenoids (>90%). The three groups yielded 1,010, 1,086 and 922 differentially accumulated metabolites, and PCA separated high- from low-resistance materials in all groups. These metabolites were significantly enriched in metabolic pathways, biosynthesis of secondary metabolites, monoterpenoid and diterpenoid biosynthesis, and phenylpropanoid biosynthesis. In conclusion, resistance of hybrid larch to D. superans is jointly conferred by the defence enzyme system, secondary metabolite accumulation and a 'terpenoid-phenolic' metabolic network: terpenoids and phenolics act synergistically via the terpenoid and phenylpropanoid pathways, together forming the core of chemical defense and supporting the breeding of insect-resistant clones.

plant biology↗

Study buddy learning is associated with academic success in undergraduate science courses

This study reports on the outcomes of a formal peer-learning program for undergraduate science students. We implemented a cohort-based study buddy program in which high-scoring students (mentors) and lower-scoring peers (proteges) were invited to form study groups based on their first assessment scores in a given course. We then compared the performance of participants versus non-participants on subsequent assessments, while examining separately the effects for mentors and proteges. Results showed similar participation benefits for students in both mentor and protege roles. These findings emphasize the value of reducing barriers to collaborative learning in higher education and highlight the study buddy program as a cost-effective and scalable approach to enhance students educational experiences.

scientific communication and education↗

Subcellular imaging of lipids and sugars using genetically encoded proximity sensors

The lipid composition of cells varies widely across organelles and between individual membrane leaflets. Transport proteins are thought to generate this heterogeneity, but measuring their functions in vivo has been hampered by limited tools for imaging lipids at relevant spatial resolutions. Here we present fluorogen-activating coincidence encounter sensing (FACES), a chemogenetic tool capable of quantitatively imaging subcellular lipid pools and reporting their transbilayer orientation in living cells. FACES combines bioorthogonal chemistry with genetically encoded fluorogen-activating proteins (FAPs) for reversible proximity sensing of conjugated molecules. We first apply this approach to identify roles for lipid transfer proteins that traffic phosphatidylcholine pools between the ER and mitochondria. We then show that transmembrane domain-containing FAPs can reveal the membrane asymmetry of multiple lipid classes in the trans-Golgi network and be used to investigate the mechanisms that generate it. Lastly, we demonstrate FACES can be applied to measure other molecule classes, like sugars.

cell biology↗

Sex differences in seizure presentation in Dravet syndrome model mice, Scn1a+/-

Dravet syndrome (DS) is an epileptic encephalopathy mostly due to haploinsufficiency of the SCN1A voltagegated sodium channel subunit. Disease presentation (i.e., severe seizures and early life mortality) is highly recapitulated in mice haploinsufficient in Scn1a (Scn1a+/-). However, phenotypic characterization in Scn1a+/- mice in a sex and temporal manner is limited. Given the reliance of mouse models for studying disease pathophysiology and for the development of novel treatments, we tested whether mortality and seizure morbidity differed among young and adult male and female Scn1a+/- animals in the F1 hybrid C57x129S6 background. We found increased mortality in female Scn1a+/- mice regardless of age compared to their male counterparts (n = 120-125 mice/sex; p < 0.05). Interestingly, long-term video EEG recordings revealed the opposite for morbidity as seizure frequency and severity were escalated in adult male Scn1a+/- animals (n = 21-30 mice/sex; p < 0.05 or p < 0.01). Adult female Scn1a+/- mice, however, are more hyperactive (p < 0.05), which could be related to sleep impairment and contribute to the increased mortality despite decreased seizure morbidity. Overall, the phenotypic presentation of Scn1a+/- mice is sex-dependent and may have translational implications for therapeutic drug discovery and basic biology understanding in DS. Short SummarySex differences in mortality and seizure morbidity are discovered in Scn1a haploinsufficient mice, Scn1a+/-, which faithfully model the epileptic encephalopathy disorder, Dravet syndrome (DS). Female Scn1a+/- mice die more across all ages, whereas adult male Scn1a+/- mice have more seizures that are of greater severity. Hyperactivity, as a proxy for sleep disruption, may contribute to the increased mortality in female Scn1a+/- mice despite decreased seizure incidence and severity. These sex-specific findings may have considerable impact in therapeutic discovery and development for DS and other SCN1A-related disorders.

neuroscience↗

Down-regulated Long Noncoding RNA HOXA11-AS affects trophoblast cell proliferation and migration by regulating RND3 and HOXA7 expression in preeclampsia

The long noncoding RNA HOXA11-AS reveals abnormal expression in numerous human diseases. However, its function and biological mechanisms remain unclear in Preeclampsia (PE). In this study, we report that HOXA11-AS was significantly downregulated in preeclampsic placental tissues and could contribute to the occurrence and development of Preeclampsia. Silencing of HOXA11-AS expression could significantly suppress trophoblast cell growth and migration, whereas HOXA11-AS overexpression facilitated cell growth in HTR-8/SVneo, JEG3 and JAR cell lines. RNA-seq analysis also indicated that HOXA11-AS silencing preferentially regulated numerous genes associated with cell proliferation and cell migration. Mechanistic analyses showed that HOXA11-AS could recruit Ezh2 and Lsd1 protein, and regulate RND3 mRNA expression in nucleus. In cytoplasm, HOXA11-AS modulate HOXA7 expression by sponged miR-15b-5p, thus affecting trophoblast cell proliferation. Together, these resulting data confirm that aberrant expression of HOXA11-AS is involved in the occurrence and development of Preeclampsia, and may act as a prospective diagnosis and therapeutic target in PE.

molecular biology↗