Biology subjects

Chow, K. L.

Publications and source records attributed to Chow, K. L..

3 recordsLinked to original sources

bioRxiv2025

Cyclohexyl acetate functions like a volatile sex pheromone mimic in Caenorhabditis nematodes

Nematodes communicate via diverse sex pheromones, including long-range volatile signals, short-range chemical cues, and contact-dependent molecules. While the ascaroside family of small molecules that mediate short-range attraction is well characterized, the identities and roles of volatile sex pheromones (VSPs) that act over longer ranges remain unknown. Using GC-MS analysis of crude VSP extracts, we identified cyclohexyl acetate (CA) as a candidate mimic, sharing retention time and mass spectral features with natural VSPs. Behavioral assays demonstrated that CA acts as a concentration-dependent, male-specific attractant in Caenorhabditis. Pre-exposure to VSPs induced cross-adaptation to CA, suggesting shared sensory processing. Surprisingly, genetic and calcium imaging analyses revealed that CA perception is mediated primarily by AWCon (str-2-expressing) neurons and involves VSPs chemoreceptor srd-1-independent pathways, which are distinct from the neural pathways involved in natural VSPs perception. These findings establish that CA is not a major component of VSPs but a structural and functional mimic of nematode VSPs, operating through a parallel sensory circuit. Although the endogenous source of CA remains unknown, its structural and behavioral mimicry provides new insights into the complexity of chemosensory signaling and the potential for interspecies chemical eavesdropping in nematode ecology.

biochemistry↗

bioRxiv2025

Chemosensory Adaptations in Caenorhabditis Males during the Establishment of Androdioecy.

Caenorhabditis elegans has evolved from its dioecious ancestors to adopt an androdioecious reproductive strategy. In this process, ancestral female C. elegans acquired genetic modifications that enabled self-sperm generation, self-sperm activation, and a reduced reliance on sexual reproduction. However, how males have adapted during this transition from dioecy to androdioecy is less explored. Using respective Caenorhabditis species, we demonstrated that androdioecious hermaphrodites exhibit a reduction in sex pheromone potency, while androdioecious males show notably heightened olfactory habituation and diminished mate exploration capabilities. The behavior of androdioecious males can be reverted to resemble that of dioecious males by replacing the SRD-1 receptor with its dioecious orthologs. This intrinsic characteristic is contingent upon the cytoplasmic domain of the receptor. We propose a theoretical framework where C. elegans males have accumulated genetic variations in their pheromone receptor, leading to altered chemosensory perception of the opposite sex, which confer a selective advantage that favors the establishment of hermaphroditism. Our study provides insights into an overlooked male trait that was shaped by changes in chemosensory signaling. The findings underscore the capacity of chemosensory variations to influence how organisms perceive critical ecological factors and eventually facilitate the emergence and stabilization of hermaphroditism.

evolutionary biology↗

bioRxiv2020

Simultaneous transcriptome and methylome profiles of single mouse oocytes provide novel insights on maturation and aging

BackgroundAdvanced maternal aging has become a worldwide public health issue that contributes to female fertility decline and significant risk to embryo development. Despite transcriptional and epigenetic alterations reported in oocyte maturation and development, the dynamics of gene expression and DNA dynamics associated with aging remain elusive. Here we generated simultaneous transcriptome and methylome profiles of mouse oocytes during aging and maturation at single-cell and single-base resolution to examine key biological processes and identify the key targets for novel treatment options. ResultsWe report the dynamics in transcriptome and DNA methylome in mouse oocytes during maternal aging and oocyte maturation. Age-associated gene expression changes showed mitochondrial dysfunction in GV oocytes and defects of chromosome segregation and spindle assembly in MII oocytes. EIF2 signaling protein synthesis pathway was also impaired during aged oocyte maturation. Moreover, distinctive DNA methylation patterns were demonstrated during maternal aging in GV and MII oocytes. A positive correlation between gene expression and methylation in gene body was characterized. Furthermore, we identified several promising biomarkers, including IL-7, to assess oocyte quality, which are potential therapeutic targets for improve oocyte maturation. More importantly, we built the first mouse oocyte maturation and age prediction model using transcriptome data and validated its feasibility in published data. ConclusionsThis work provides a better understanding of molecular and cellular mechanisms during mouse oocyte aging, points a new direction of oocyte quality assessment, and paves the way for developing novel treatments to improve oocyte maturation and quality in the future.

genomics↗