Biology subjects

Garcia, S. R.

Publications and source records attributed to Garcia, S. R..

4 recordsLinked to original sources

bioRxiv2025

The effects of temperature on nestling growth in a songbird depend on developmental and social context

Climate change can adversely impact animals, especially those that cannot independently thermoregulate or avoid exposure. Cold, hot, and variable temperatures may impede nestling songbird growth due to increased thermoregulatory costs and reduced food delivery by parents. At a broad scale, temperature effects on nestling growth vary across climatic zones, but how temperature effects vary with early-life developmental constraints imposed by the timing of thermoregulatory development, competition with siblings, and the amount of parental care has received less attention. We investigated whether the effect of temperature on the mass of wild barn swallow (Hirundo rustica erythrogaster) nestlings (n = 113 nestlings, 31 nests) in Boulder County, CO depends on timing of exposure during development, relative size within the brood, or level of parental feeding. We found that the effect of minimum temperature differed in early and late development (before versus after putative development of thermoregulatory independence) and may be less pronounced for nestlings that received more parental feeding. We did not find evidence that the smallest nestling in the brood differs from other nestlings in vulnerability to temperature. These findings indicate the existence of fine-scale heterogeneity in which the effects of temperature on nestling development are sensitive to metabolic constraints and early-life social environment, providing key insight into the factors that may ameliorate or exacerbate climate impacts on individual birds.

ecology↗

bioRxiv2025

Perinatal Shifts in Fecal-Derived Metabolites and Associations with Postpartum Depression

IntroductionResearch on maternal depression is largely limited to static, blood-derived biomarkers in the postpartum period and mechanistic targets derived from populations outside the physiological contexts of pregnancy and postpartum, resulting in critical gaps in understanding context-specific mechanisms underlying this debilitating condition. ObjectivesTo examine temporal shifts in the maternal gut metabolome and associations between pregnancy-specific shifts and postpartum depression (PPD). MethodsWe applied untargeted metabolomics (UPLC-MS/MS) to fecal samples collected from participants (N= 25) enrolled in the Maternal and Infant NutriTion (MINT) study. Random forest analysis was used to identify key pathways and metabolites contributing to temporal shifts. Fold change analysis and paired t-tests were used to quantify the magnitude and significance of metabolite changes. Associations between pregnancy-specific changes and PPD (Edinburgh Postnatal Depression Scale at 6 weeks) were identified using Pearsons correlation. ResultsLipid, amino acid, and xenobiotic metabolism emerged as core pathways driving temporal changes in the maternal gut metabolome. The most pronounced shifts occurred from 35 weeks gestation to postpartum, with 55 metabolites significantly altered compared to 24 from 24-to 35 weeks gestation and 26 from 24 weeks gestation to postpartum. Of the 29 metabolites associated with PPD; 68.9% were metabolic intermediates, primarily involved in lipid and amino acid metabolism (58.6%). ConclusionsThis study provides some of the first evidence of temporal shifts in the maternal gut metabolome and associations with PPD, highlighting the importance of lipid and amino acid metabolism and laying the groundwork for future multi-omics research.

systems biology↗

bioRxiv2024

In Silico identification and modelling of FDA-approved drugs targeting T-type calcium channels

Studies have shown that inhibition of the Cav3.1 T-type calcium channel can prevent or suppress neurological diseases, such as epileptic seizures and diabetic neuropathy. In this study we aimed to use in silico simulations to identify a U.S. Food and Drug Administration (FDA)-approved drug that can bind to the Cav3.1 T-type calcium channel. We used the automated docking suite GOLD v5.5 with the genetic algorithm to simulate molecular docking and predict the protein-ligand binding modes, and the ChemPLP empirical scoring function to estimate the binding affinities of 2,115 FDA-approved drugs to the human Cav3.1 channel. Drugs with high binding affinity and appropriate pharmacodynamic and pharmacokinetic properties were selected for molecular mechanics Poisson-Boltzmann surface area (MMPBSA) and molecular mechanics generalised Born surface area (MMGBSA) binding free energy calculations, GROMACS molecular dynamics (MD) simulations and Monte Carlo Cell (MCell) simulations. The docking results indicated that the FDA-approved drug montelukast has a high binding affinity to Cav3.1, and data from the literature suggested that montelukast has the appropriate drug-like properties to cross the human blood-brain barrier and reach synapses in the central nervous system. MMPBSA, MMGBSA and MD simulations showed the high stability of the montelukast-Cav3.1 complex. MCell simulations indicated that the blockage of Cav3.1 by montelukast reduced the number of synaptic vesicles being released from the pre-synaptic region to the synaptic cleft, which may reduce the probability and amplitude of postsynaptic potentials. Author SummaryNew drugs for current illnesses or disorders are always necessary to enhance therapeutic outcomes or can be utilised for patients who have experienced side effects from current medicines. The Cav3.1 T-type calcium channel has been found to be linked to neurological diseases, such as epilepsy and diabetes. Consequently, identifying a drug that could bind to these receptors may yield therapeutic effects on these neurological conditions. This study utilises various computational methods to sift through 2,115 FDA-approved drugs that have been used for other diseases, not neurological ones, to determine whether some of these drugs could bind to the Cav3.1 T-type calcium channel and potentially produce therapeutic effects on neurological diseases. Our research indicates that the current asthma drug montelukast has the potential to bind to the calcium channel and is worthy of further investigation.

bioinformatics↗

bioRxiv2020

A sexual dimorphism in the spatial vision of band-winged grasshoppers

Visual acuity (VA) --- a measurement of the fineness or coarseness of vision --- correlates with the size of an animal, with larger species often possessing sharper vision. However, it is unknown whether the same relationship between visual acuity and size holds within a species when individuals differ consistently and substantially in size, such as through a sexual size dimorphism. Here we examine the visual acuity of three species of sexually dimorphic band-winged grasshoppers, in which females are the larger sex (Arphia pseudonietana, Dissosteira carolina, and Spharagemon equale; total n = 98). Using a radius of curvature estimation method, we find that females have [~]21% finer vision in the most acute region and axis of the eye than do males. Further explorations of the eyes of the species showing the greatest size dimorphism (D. carolina) suggest that this VA dimorphism is driven by females having larger eyes with more ommatidia. In contrast to many flying insects where males have finer vision to acquire mates, our study is one of the first to demonstrate a female-biased sexual dimorphism in acuity. Given the number of species in which females are larger than males, our results suggest that differences in VA between the sexes may be more common than currently appreciated.

physiology↗