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Undergraduate research (UR) is regarded as an impactful instructional practice, but implementing it in the curriculum is challenging. Faculty members' approaches to the design of UR are under-explored due to the scarcity of studies that situate practices in both the curricular contexts and the concept of the research-teaching nexus. This multiple-case study investigated faculty members' approaches to UR in four curricula in two research-intensive universities in Hong Kong. Document review and semi-structured interviews revealed five approaches to UR: project-based, process-based, lab-based, scenario-based, and research community-based approaches. Particularly, the scenario-based and research community-based approaches complemented the current typologies. Another contribution of this study is the identification of nuanced differences in the adoption of the approaches. Faculty members perceiving reciprocal research-teaching nexus at both departmental and personal levels, and viewing UR holistically, tended to connect students with their own research experiences. In contrast, those who only acknowledged the research-teaching nexus at a departmental level were unlikely to create such a connection. Meanwhile, concerns over curricular coherence and ethics were also discussed. The implications include creating a more transparent process of curriculum design and facilitating students' understanding of their contributions to the research community. It would also be useful to engage faculty members more fully in curriculum planning to enhance the coherence of students' research experiences.

Background The coronavirus disease 2019 (COVID-19) pandemic has resulted in changes in lifestyle habits and experiences of mental health outcomes, some of which were possibly related to weight gain, leading to an increase in the prevalence of obesity, which is associated with the development of several severe diseases. Concerns regarding weight gain and its impact on health outcomes are prevalent worldwide, with obesity being one of the highest causes of mortality in current society. Methods A self-reported questionnaire collected data from participants aged 18 years of age and above from 26 countries and regions worldwide. Post-hoc multiple logistic regression analyses have been done to evaluate the association between demographic and socioeconomic factors, and the perspectives that were identified to be associated with weight gain. Results Participants belonging to a younger age group; with a higher level of education; living in an urban area; living with family members; employed full-time; and had obesity were found to be more vulnerable to weight gain. After adjusting for socio-demographic factors, participants who were quarantined; exercised less prior to the pandemic; consumed unhealthy foods; and reported negative thoughts such as helplessness and the perceived risk of COVID-19, were more likely to experience weight gain; while negative thoughts such as having no means of control over the COVID-19 pandemic and the consequences of the COVID-19 pandemic will have great personal effect were associated with females, students, and people living in the rural area. Conclusions Weight gain risk during the pandemic was significantly associated with certain socio-demographic and COVID-19 related factors. To improve public health outcomes, future research should conduct a longitudinal evaluation on the effects of COVID-19 experiences upon health choices. Streamlined mental support should also be provided to the vulnerable groups which were prone to negative thoughts tha

The implementation of a research-based curriculum that enables students to develop essential capabilities for this complex world is challenging. There is limited understanding of the implementation of a research-based curriculum in a whole degree programme, and few studies examined how faculty members and students perceived such a curriculum. This study explored faculty members’ perceptions and students’ experiences of four research-based curricula in two research-intensive universities in Hong Kong. Based on document review, 18 faculty interviews, and 113 student interviews, we discovered an overall positive view of research-based curricula but also substantial differences between faculty members’ perceptions and students’ experiences. For example, faculty members emphasised the learning and critical evaluation of knowledge. In comparison, students focused on exploring specific interesting issues and collecting and analysing information without fully recognising the potential of research in generating, applying, and validating knowledge. Moreover, students’ experiences of research-based curricula contained a broader scope of activities than the curriculum perceived by faculty members. These gaps demonstrate that the fundamental goals of research-based curricula to develop ‘powerful knowledge’ and induct students into disciplinary ways of thinking have yet to be fully achieved. The study implies a need to enhance communication between students and faculty members and build a consensus on designing and supporting undergraduate research across the curriculum. © 2023, The Author(s).

Advanced maternal aging has become a worldwide public health issue contributing to female fertility decline. To provide a complete landscape of transcriptome and epigenetic changes during oocyte aging and maturation, we applied a parallel bimodal genomics approach to parallel transcriptome and methylome profiles of mouse oocytes at single-cell and single-base resolution. Age-associated gene expression changes were associated with defective spindle assembly and mitochondrial dysfunction. Parallel sequencing data suggested aged-related defects in mRNA degradation and methylome remodelling during oocyte maturation. Differentially methylated region in aged mature oocyte was associated with trimethylation of Histone H3 at Lysine 4. More importantly, RNA expression-based prediction model for assessing maturation and oocytes age. Taken together, our work provides a better understanding of molecular mechanisms during mouse oocyte aging, points a new direction of oocyte quality assessment and paves the way for developing novel treatments to improve oocyte quality. © 2022 The Authors

The size regulation of an organism’s body and cells is a fundamental biological process, which involves signalling pathways. In C. elegans, BMP (Bone Morphogenetic Proteins) signalling, a pathway controlling developmental processes in many species, is known regulating worm body volume, length and hypodermal ploidy. These size parameters are often used to monitor BMP level (intensity of BMP signaling activity), in the studies about body size control through BMP signals. The reliability of the conventional BMP level indicators is doubted, as BMP- related research expands broader and deeper and identifies more BMP mutants. The conventional indicators may not be sensitive enough to distinguish among BMP mutants. In addition, the ploidy measurement can be affected by the staining process and conditions. Therefore, we seek alternative BMP level indicators which are more sensitive and reliable than the conventional ones. Three alternative BMP level indicators are identified in the study, which are the volume and length of Int2 cell (a polyploid intestinal cell), and worm body aspect ratio. Int2 cell volume is the most sensitive among the tested BMP level indicators, but its sensitivity is not outstanding among others. Moreover, all the tested BMP indicators responds non-linearly to BMP levels. This implies that the reliability of both conventional and alternative BMP level indicators is comparable. However, these indicators still help people determine if the BMP level of worms is higher or lower than WT worms. To improve and find more alternatives of BMP indicators, it is suggested to develop different types of BMP level indicators, such as transcriptional reporters (fluorescence tag expression driven by the promoter of the genes known to be regulated by BMP signalling). Using multiple indicators to monitor BMP level should also be considered.

Anthropogenic emission of carbon dioxide (CO2) leads to ocean warming (OW) ocean acidification (OA). Despite the growing number of studies of their impacts, whether organisms can respond quickly to such changing conditions remains unclear. Phenotypic plasticity is one major mechanism through which organisms cope with environmental variations. Such plasticity can be passed on to subsequent generation through maternal provision and/or epigenetics. To test the overall hypothesis that pre-exposure to environmental stressors confers greater resilience to future climate conditions, three major studies were performed. Focusing on the non-indigenous slipper limpet Crepidula onyx, I investigated if stress response differed between populations. The introduced population in Hong Kong have larger eggs and shorter pelagic larval duration than the natives from California. Larvae from native population suffered increased mortality when starved but not the invasive ones, suggesting the possibility of local selection and/or genetic drift. When native adults are conditioned to warmer Hong Kong water temperature, their offspring had slower growth rates, highlighting tradeoff between maintenance and reproduction under stress. I then focus on behavioral plasticity of C. onyx to direct and indirect, trophic mediated effects of OA. While the nutritional quality of their algal food decreased in OA, the exposed larvae were able to cope with these stresses by increasing clearance rates and settling earlier to escape the stressful conditions in the water column. Such plasticity in behaviors was also observed in larval sand dollars, Dendraster excentricus, which swim to avoid low pH water strata. Finally, I tested if long-term exposure within and across generations enhances resilience. Individuals reared under OA from hatching through sexual maturity had higher mortality and reduced fecundity, but the size of their larvae were comparable to those in control condition. Transgeneratio

In spite of recent medical advancements, heart disease remains a leading cause of death worldwide. Some congenital cardiac malformations can result from heart looping defects. The heart looping is a crucial process for ensuring that the future heart chambers are aligned properly to ensure the correct function of the heart. The zebrafish has become a favored vertebrate model for studying cardiac development and disease. However, there is a lack of standardised methodology to quantitatively characterize the heart looping. One aim of this study is to provide a standardized method to quantify the heart looping degree using the zebrafish model. My method relies on access to a light sheet microscope, and 3D analysis software, and it provides various parameters to quantify the heart looping. With this approach, I can compare these parameters on any heart phenotypes. Furthermore, while the requirement for Ca2+ during normal heart function is well known, more recent evidence suggests that Ca2+ might also play a key role in heart morphogenesis. Thus, having a better understanding of the role of Ca2+ signaling in normal heart development might help identify novel therapies for acquired heart diseases, and indicate possible therapeutic options for pharmacological/genetic intervention to promote heart repair and regeneration. My data show that the introduction of the Ca2+ chelator, BAPTA-4K, or the treatment of zebrafish with various Ca2+ channel inhibitors during the heart tube formation and the heart looping affect the looping process with the observation of abnormal heart phenotypes, including misalignments of the ventricle and atrium, a decrease in the volume of the heart chambers, and failure in heart looping. My results suggest that Ca2+ signaling, potentially through the IP3Rs actions, might be important for heart looping and the generation of the heart chamber volume, and thus the overall morpho

Pheromones are critical cues for attracting mating partners for successful reproduction. Sexually mature Caenorhabditis remanei virgin females and self-sperm-depleted Caenorhabditis elegans hermaphrodites produce volatile sex pheromones to attract adult males of both species from afar. The chemoresponsive receptor in males has remained unknown. Here, we show that the male chemotactic behavior requires amphid sensory neurons (AWA neurons) and the G-protein-coupled receptor SRD-1. SRD-1 expression in AWA neurons is sexually dimorphic, with the levels being high in males but undetectable in hermaphrodites. Notably, srd-1 mutant males lack the chemotactic response and pheromone-induced excitation of AWA neurons, both of which can be restored in males and hermaphrodites by AWA-specific srd-1 expression, and ectopic expression of srd-1 in AWB neurons in srd-1 mutants results in a repulsive behavioral response in both sexes. Furthermore, we show that the C-terminal region of SRD-1 confers species-specific differences in the ability to perceive sex pheromones between C. elegans and C. remanei. These findings offer an excellent model for dissecting how a single G-protein-coupled receptor expressed in a dimorphic neural system contributes to sex-specific behaviors in animals. © 2019 The Authors

Objective: Myeloid-derived suppressor cells (MDSCs) contribute to tumour immunosuppressive microenvironment and immune-checkpoint blockade resistance. Emerging evidence highlights the pivotal functions of cyclin-dependent kinases (CDKs) in tumour immunity. Here we elucidated the role of tumour-intrinsic CDK20, or cell cycle-related kinase (CCRK) on immunosuppression in hepatocellular carcinoma (HCC). Design: Immunosuppression of MDSCs derived from patients with HCC and relationship with CCRK were determined by flow cytometry, expression analyses and co-culture systems. Mechanistic studies were also conducted in liver-specific CCRK-inducible transgenic (TG) mice and Hepa1-6 orthotopic HCC models using CRISPR/Cas9-mediated Ccrk depletion and liver-targeted nanoparticles for interleukin (IL) 6 trapping. Tumorigenicity and immunophenotype were assessed on single or combined antiprogrammed death-1-ligand 1 (PD-L1) therapy. Results: Tumour-infiltrating CD11b+CD33+HLA-DR- MDSCs from patients with HCC potently inhibited autologous CD8+T cell proliferation. Concordant overexpression of CCRK and MDSC markers (CD11b/CD33) positively correlated with poorer survival rates. Hepatocellular CCRK stimulated immunosuppressive CD11b+CD33+HLA-DR- MDSC expansion from human peripheral blood mononuclear cells through upregulating IL-6. Mechanistically, CCRK activated nuclear factor-κB (NF-κB) via enhancer of zeste homolog 2 (EZH2) and facilitated NF-κB-EZH2 co-binding to IL-6 promoter. Hepatic CCRK induction in TG mice activated the EZH2/NF-κB/IL-6 cascade, leading to accumulation of polymorphonuclear (PMN) MDSCs with potent T cell suppressive activity. In contrast, inhibiting tumorous Ccrk or hepatic IL-6 increased interferon γ+ tumour necrosis factor-α+CD8+T cell infiltration and impaired tumorigenicity, which was rescued by restoring PMN-MDSCs. Notably, tumorous Ccrk depletion upregulated PD-L1 expression and increased intratumorous CD8+ T cells, thus enhancing PD-L1 blockade efficacy

MAB21L2(R51C) is one of the five documented MAB21L2 mutations in human patients with bilateral eye malformations identified via whole exome sequencing. In addition to the eye abnormality, patients with MAB21L2(R51C/+) mutation also have skeletal dysplasia and intellectual disability. To evaluate the pathology of this mutant allele systematically in understanding the functional role of MAB21L2 in human development, we introduce the R51C mutation into the mouse genome by CRISPR/Cas9 system to generate a mouse model for detailed characterization. The Mab21l2(R51C/+) mice have eyeless phenotype and skeletal abnormalities. Micro-computed tomography (micro-CT) analysis showed the Mab21l2(R51C/+) mice have no eye balls but with two abnormal tissues underneath the brain. Histological analysis revealed that the early eye development in the mutant embryos is interrupted. In addition, Mab21l2(R51C/+) mice also have joint fusion phenotype; the humerus is fused with radius, whereas femur is fused with tibia. Limbs in the mutant animals are distinctly shorter than the wild type; and deltoid tuberosities in humeri are absent in these Mab21l2(R51C/+) mice. In summary, we showed that our Mab21l2(R51C/+) mutant mice have recapitulated the pathological features in eye and bone of human patients. Further analyses of the mutant phenotype with molecular markers will provide insight on how MAB21L2 guides the optic differentiation and skeletogenesis, revealing specific underlying pathogenic mechanism of the MAB21L2(R51C) mutation.

Pulse transit time (PTT) has been a promising non-invasive and cuff-less method to measure blood pressure (BP). However, to achieve acceptable accuracy, subject specific and frequent calibration is required to model the complex non-Iinear dynamic between BP and PTT, limiting the practicality of PTT-based methods. The BP-PTT relationship is often modelled by the Moens-Korteweg (M-K) equation. Previous studies have found that the M-K equation is only able to model high frequency variations of BP, with low frequency variations modulated by the vasomotor tone, which is regulated by the sympathetic nervous system (SNS). In this paper we present a novel calibration procedure that accounts for the influence of the SNS on the BP-PTT relationship. This is achieved by identifying the state of the SNS during calibration based on heart rate (HR), respiratory rate (RR), and PTT itself. The performance of the proposed procedure has been tested on 10 subjects over a period of 4 weeks. The results showed that the measurement differences were 1.04 mmHg ± 6.88 mmHg, and -2.16mmHg ± 6.60 mmHg for systolic and diastolic blood pressure, respectively. Furthermore, the proposed procedure was found to make a significant improvement of measurement precision when compared to the previous one-point calibration method, demonstrating the potential of the new procedure for accurate long-term BP tracking. © 2018 IEEE.

Both sexually matured C. remanei virgin females and self-sperm exhausted C. elegans hermaphrodites release a long-range volatile sex pheromone to attract adult males from afar. Previously, we reported that this chemotaxis behavior requires CEM, AWA and AIZ neurons. In AWA, a GPCR SRD-1 has been demonstrated as the receptor of this pheromone. Ectopic expression of srd-1 in AWB in srd-1 male elicited distinct repulsive behaviour towards pheromone; this result indicated the sufficiency of the SRD-1 receptor acting in AWA. From calcium imaging, we further confirmed the receptor was necessary for the excitation of AWA upon pheromone induction. Male C. elegans is the least attracted to pheromone in comparison to C. briggase, C. remanei, and C. brenneri. Endogenous srd-1 expression level is lower than that of its orthologue, cre-srd-1, in male C. remanei. Transformation rescue of the male srd1 mutant in C. elegans by cre-srd-1 cDNA was shown to be more responsive to pheromone than those rescued by srd-1 cDNA. Based on protein structure analysis and protein sequence alignment, SRD-1 receptors across four nematode species were highly conserved in terms of their sequences and structure, except their C-terminal region (CT). Six amino acid sequences are polymorphic in C. elegans SRD-1 extracellular loop regions (ECL). The ECL polymorphisms substituted versions of SRD-1 cDNA cannot elicit a higher responsiveness to this pheromone. However, CT truncated cre-srd-1 and srd-1 cDNA are unable to rescue srd-1 chemotaxis mutant phenotype, suggesting the CT region to be critical for SRD-1 function. Specifically, after the CT domain was swapped between Cre-SRD-1 and SRD-1, the transgenic line carrying cre-srd-1-CT-swapped-in-srd-1 cDNA is more attracted to this pheromone than the one carrying srd-1-CT-swapped-in-cre-srd-1 cDNA. Since the CT region in GPCR is usually related to the intracellular signal transduction, we envision that both the expression level of gene product and intracellu

Mab21l2 is a member of a gene family well conserved from invertebrates to vertebrates. In invertebrate model, mab-21 works downstream of BMP/TGF-ß signaling pathway in sensory organ formation. Genetic ablation of Mab21l2 in mouse leads to severe eye malformation and embryonic lethality at mid-gestation stage. Although wild type MAB21L2 protein can bind to ssRNA, the function remains unknown. Five missense mutations in MAB21L2 were identified by exome sequencing from samples of human patients with bilateral eye malformations. These patients also have skeletal dysplasia and intellectual disability (Rainger et al., 2014; Deml et al., 2015). The phenotype is most severe in patients with the dominant MAB21L2R51C/+ mutation. To evaluate the pathology of this mutant allele systematically, we adopt the CRISPR/Cas9 system to introduce this same mutation into the mouse genome. The Mab21l2R51C/+ mutant mice showed small eye phenotype and contractures in both elbow and knee joints. While the eye balls were absent in the mutant mice, optic nerves and two abnormal neuro epithelial structures expressing retinal specific markers, e.g., Pax 6, were found to be connected with hypothalamus. The abnormal tissue was likely to be the remnants of the retina during the eye formation. In addition, micro-CT also showed that the joint contracture was caused by joint fusion. The humerus was fused with radius in the elbow, while femur was fused with tibia. Limbs in the mutant animals were distinctly shorter than the wild type; and the deltoid tuberosity in humeri was also absent in these Mab21l2R51C/+ mutant mice. In summary, the phenotypes of our Mab21l2R51C/+ mutant mice generated by CRISPR/Cas9 system recapitulate all the pathological features of human patients. Further analyses of the mutant phenotype will provide insight on how MAB21L2 guides the optic differentiation and the joint formation, revealing specific underlying pathogenic mechanism of the MAB21L2(R51C) mutation.

Mutations in the Pick1 gene cause globozoospermia, a male infertility disorder, in both mice and humans. PICK1 is crucial for vesicle trafficking, and its deficiency in sperm cells leads to abnormal vesicle trafficking from the Golgi to the acrosome. This eventually disrupts acrosome formation and leads to male infertility. Here, we identified ICA1L, which has sequence similarities to ICA69 (also known as ICA1), as a new BAR-domain binding partner of PICK1. ICA1L is expressed in testes and brain, and is the major binding partner for PICK1 in testes. ICA1L and PICK1 are highly expressed in spermatids and trafficked together at different stages of spermiogenesis. ICA1L-knockout mice were generated by CRISPRCas technology. PICK1 expression was reduced by 80% in the testes of male mice lacking ICA1L. Sperm from ICA1L-knockout mice had abnormalities in the acrosome, nucleus and mitochondrial sheath formation. Both total and mobile sperm numbers were reduced, and about half of the remaining sperm had the characteristics of globozoospermia. These defects ultimately resulted in reduced fertility of male ICA1L-knockout mice, and ICA69/ICA1L-double knockout male mice were sterile. © 2015.

Our lab studies the molecular basis of chemosensory behaviors. Sexually mature C. remanei females produce an attractant detectable by conspecific adult males and its relative C. elegans. The volatile attractant acts in a sex-, stage- and species-specific manner and thus qualifies as a long-range sex pheromone. Analysis on GC-MS data suggested several chemicals and two among them were functionally verified by chemo-attraction assays. A mixture of the two exhibited stronger attractiveness than either one alone, suggesting a synergistic effect behind. On another focus, we search for the corresponding receptors. Previously we reported cell ablation experiments that demonstrated the necessity of CEM, AWA and AIZ neurons in this process. In AWA, SRD-1 was identified as a GPCR responding for sex pheromone perception, corroborated by the localization, single cell microarray data, mutation strain function examine and cell specific cDNA rescue experiments. Ectopically srd-1 expression from AWA to AWB elicits a distinct repulsive behavior towards pheromone in males, demonstrating its sufficiency as a pheromone receptor. Noticeably, the two pheromone candidates above could not attract srd-1 mutant worms, further strengthening the ties between the suggested ligands and receptor. To screen for potential receptors in the CEM, we conduct a cell-specific RNA pull down on transgenic hermaphrodites. Hermaphrodites without CEM neurons to carrying CEM neuron with increasing male-fated mutations show gradually increased attraction towards sex pheromones. We thus hypothesize CEM cells of the right fate must be expressing sets of molecules that confer masculinity. Comparison between transcriptome profiles should reveal key differences between non-functional and functional CEM neurons, and screen out relevant receptors. (The study is supported by Research Grants Council, Hong Kong.).

Epithelial cell junctions are crucial for cell adhesion, cell-cell communication and morphogenesis. In C. elegans, how the components of adherens junctions are assembled in organogenesisis is largely unknown. We have previously reported that a claudin-like protein NSY-4, located at the apical junctions, is required for sensory ray assembly. nsy-4 knockdown in either ray hypodermis or structural cells alone is sufficient to generate ray-missing males. Like its claudin homologs in vertebrates, NSY-4 contains a functional PDZ binding motif and intracellular C-terminus, which are dispensable for correct localization, while mutation of the GLW motif leads to intracellular retention of the protein. These results suggest that NSY-4 functions similarly as its vertebrate counterparts do and may mediate adhesion by direct homophilic binding. NSY-4 also requires HMR-1, the classical cadherin, for correct localization and the two co-localize at the ray tips. hmr-1 and nys-4 double knockdown enhances the ray missing phenotype, implying functional interaction between the two proteins. In addition, homeobox transcription factor ceh-43 knockdown reduces nsy-4 expression level via a transcriptional reporter assay, pointing nsy-4 as a downstream target of ceh-43. Given these results, we propose NSY-4 is an additional building block in C. elegans male sensory ray. Further studies on NSY-4, such as homophilic interaction, mapping of membrane localization domain and interaction with other adherens junctional proteins, should reveal more information on the roles of claudin-like proteins in nematode organ formation.

Finding a mating partner is an obligated process for the survival of sexual species. C. elegans males show prominent chemo-attractive response to the sex pheromone released by females of a dioecious species – C. remanei, implicating a mating cue. This chemotactic response towards sex pheromone is controlled by a pair of male-specific CEM neurons. Despite its role in chemo-sensation implicated by their ciliary endings, the biological function of these neurons remains elusive. We showed that C. elegans males lacking intact CEM cilia by depleting IFT (Intraflagellar transport) proteins displayed a notable weakened sex pheromone response, suggesting that CEMs are sensory neurons. We also sought to identify the molecular components acting in CEMs, including G proteins. The C. elegans genome encodes 21 G-alpha, 2 G-beta and 2 G-gamma subunits. We systematically examined the expression of these genes in CEM and evaluated their function in CEM by cellspecific knockdown. We found that goa-1 (gene encoding G-alpha), gpb-1 (gene encoding G-beta) and gpc-2 (gene encoding G-gamma) are expressed in CEMs, and knockdown of these genes impaired animal response towards sex pheromone. These results indicate Go-mediated signaling occurs in the CEMs to regulate sex pheromone chemotaxis. How these G proteins are coupled with the receptor for sex pheromone perception by CEM will be discussed.

The photosynthetic Rhodobacter species are promising alternative expression hosts in bioproduction and biorefinery due to their unique metabolic capacities. With prominent inner membrane areas and efficient endogenous translocation machineries, they are especially attractive for membrane protein expression. However, codon usage bias could be a limitation in the engineering of Rhodobacter species and has seldom been investigated. In this study, we tackled the codon bias of Rhodobacter by functionally expressing 8 rare tRNAs of Rhodobacter sphaeroides with a multi-copy vector. The impact of tRNA supplementation was evaluated through monitoring expression levels of two heterologous proteins with different phylogenetic origins, a membrane subunit of the riboflavin transporter, RibU, from Lactobacillus acidophilus La-14 and a decaheme cytochrome, MtrA, from Shewanella oneidensis. Our results showed that the performances were closely related to medium composition and rare codon percentages of raw DNA sequences. Provision of rare tRNAs has increased RibU production by 7.7-folds and 2.86-fold in minimal medium and rich medium, respectively, while MtrA levels were increased by 1-fold in minimal medium. The present study confirms the presence of codon bias in R. sphaeroides and offers a facile tool for improving heterologous expression of rare-codon containing genes. We anticipate that this tRNA supplementation system can be further extended to other species of Rhodobacter, and thus will facilitate the engineering of purple bacteria for interesting applications in microbial technology.