Biology subjects

James, C. T.

Publications and source records attributed to James, C. T..

3 recordsLinked to original sources

bioRxiv2025

A Case Study Leveraging Angler Reported Data For Whirling Disease Monitoring

The Bow River (Alberta, Canada) has a well-documented decline in its rainbow trout fishery, with several stressors attributed to this decline including whirling disease (WD). This study evaluated whether anglers could detect recruitment failure in WD-impacted areas of the Bow River drainage using a smartphone app-based citizen science initiative. Anglers reported age 1 and 2 rainbow and cutthroat trout identified by size distribution, estimated from a provincial database, across 4 sub-watersheds with varying densities of Myxobolus cerebralis actinospores (TAMs), a known predictor of WD severity. TAM densities ranged from undetectable (0 TAMs/L - Waiparous Creek) to moderate (< 0.01 TAMs/L - Sheep and Highwood Rivers) and high (> 0.01 TAMs/L - Jumpingpound Creek). No fish were captured in Jumpingpound Creek over 20.2 angling hours. The Highwood and Sheep Rivers had catch rates of 0.4 and 0.2 age 1 and 2 trout per hour over 30.6 and 27.7 hours, respectively. Waiparous Creek, where WD was absent, had a significantly higher catch rate of 2.2 trout per hour over 20.3 hours. These findings suggest that self-reported angler data can potentially help identify recruitment losses in WD-impacted areas, demonstrating a novel application of citizen science in fisheries research.

ecology↗

bioRxiv2024

Cyclin O controls entry into the cell-cycle variant required for multiciliated cell differentiation

Multiciliated cells (MCC) ensure proper fluid circulation in various organs in metazoans. Their differentiation is marked by the massive ampliication of cilia-nucleating centrioles and is known to be controlled by various cell cycle components. Tn a companion study, we show that the differentiation of MCC is driven by a genuine cell-cycle variant characterized by sequential and wave-like expression of canonical and non-canonical cyclins such as Cyclin O (CCNO). Patients with CCNO mutations exhibit a subtype of Primary Ciliary Dyskinesia (PCD) designated as Reduced Generation of Multiple Motile Cilia (RGMC), yet the role of CCNO during MCC differentiation remains unclear. Here, using mice and human cellular models, single cell transcriptomics and functional studies, we show that Cena is activated during a strategic temporal window at the crossroads between the onset of MCC differentiation, the entry into the MCC cell cycle variant, and the activation of the centriole biogenesis program. We ind that the absence of Cena leads to a block of MCC progenitor differentiation at the G1/S-like transition, just before the beginning of centriole formation. This leads to a complete lack of centrioles and cilia in mouse brain and human airway MCC. Altogether, our study identifies CCNO as a core regulator of entry into the MCC cell cycle variant and shows that the coupling of centriole biogenesis to an S-like phase, maintained in MCC, is dependent on CCNO. One sentence summaryCyclin O is necessary for multiciliated cells to enter their differentiation cell cycle variant and allows the massive amplification of centrioles, which serve as basal bodies for cilia nucleation.

cell biology↗

bioRxiv2019

The transcriptional landscape of the murine middle ear epithelium in vitro

Otitis media (OM) is the most common paediatric disease and leads to significant morbidity. Although understanding of underlying disease mechanisms is hampered by complex pathophysiology, it is clear that epithelial abnormalities underpin the disease. The mechanisms underpinning epithelial remodelling in OM remain unclear. We recently described a novel in vitro model of mouse middle ear epithelial cells (mMEECs) that undergoes mucociliary differentiation into the varied epithelial cell populations seen in the middle ear cavity. We now describe genome wide gene expression profiles of mMEECs as they undergo differentiation. We compared the gene expression profiles of original (uncultured) middle ear cells, confluent cultures of undifferentiated cells (day 0 of ALI) and cells that had been differentiated for 7 days at an ALI. >5000 genes were differentially expressed among the three groups of cells. Approximately 4000 genes were differentially expressed between the original cells and day 0 of ALI culture. The original cell population was shown to contain a mix of cell types, including contaminating inflammatory cells that were lost on culture. Approximately 500 genes were upregulated during ALI induced differentiation. These included some secretory genes and some enzymes but most were associated with the process of ciliogenesis. Our in vitro model of differentiated murine middle ear epithelium exhibits a transcriptional profile consistent with the mucociliary epithelium seen within the middle ear. Knowledge of the transcriptional landscape of this epithelium will provide a basis for understanding the phenotypic changes seen in murine models of OM.

genomics↗