Biology subjects

Adams, R. M.

Publications and source records attributed to Adams, R. M..

3 recordsLinked to original sources

bioRxiv2025

AAV-mediated gene therapy for SLC13A5 citrate transporter disorder rescues epileptic and metabolic phenotypes

SLC13A5 citrate transporter disorder is a rare epileptic encephalopathy caused by loss of function pathogenic variants in the SLC13A5 gene. Loss of sodium/citrate cotransporter (NaCT) function causes a severe early life epilepsy resulting in life-long developmental disabilities and increased extracellular citrate. Current antiseizure medications may reduce seizure frequency, yet more targeted treatments are needed to address the epileptic and neurodevelopmental SLC13A5 phenotype. We performed preclinical studies in SLC13A5 deficient mice evaluating phenotype rescue with adeno-associated virus (AAV) vector carrying a functional copy of the human SLC13A5 gene (AAV9/SLC13A5). Cerebrospinal fluid-delivery of AAV9/SLC13A5 decreased extracellular citrate levels, normalized electrophysiologic and sleep architecture abnormalities, and restored resistance to chemically induced seizures and death. Treatment benefits were achieved with administration during early brain development and in young adult mice, supporting a broad therapeutic window for this disorder. Comparison of delivery routes in young adult KO mice showed that higher brain targeting achieved with intra-cisterna magna delivery resulted in greater treatment benefit as compared to intrathecal lumbar puncture delivery. Together, these results support further development of AAV9/SLC13A5 for treating SLC13A5 citrate transporter disorder. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=90 SRC="FIGDIR/small/663044v1_ufig1.gif" ALT="Figure 1"> View larger version (20K): org.highwire.dtl.DTLVardef@ddc591org.highwire.dtl.DTLVardef@1d5e967org.highwire.dtl.DTLVardef@ce6c2forg.highwire.dtl.DTLVardef@209176_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2024

Vertical transmission of fungus-growing ant microbiota is species-specific and constrained by queens

Multipartite symbioses are inherently complex, involving dynamic ecological interactions between organisms with intertwined yet distinct evolutionary histories. The fungus-growing (attine) ants facilitate maintenance of a symbiotic species network through maternal vertical transmission of an obligate fungal symbiont. While the gut microbiomes of fungus-growing ant species are remarkably simple, their fungal gardens support diverse microbial communities. Here, we focus on an understudied transmission bottleneck: the fungal garden pellet that nest-founding queens transfer to inoculate a new fungal garden. We used 16S rRNA metagenomic sequencing to reconstruct the extent of vertical transmission of bacteria to new gardens via queen pellets in four sympatric fungus-growing ant species (Atta sexdens, Atta cephalotes, Acromyrmex echinatior, and Mycetomoellerius mikromelanos) from Central Panama. We also characterized the bacterial communities associated with queen eggs and somatic tissues (mesosomas, guts and ovaries) to assess whether queens are likely to transmit symbiotic bacteria of workers, such as cuticular Actinobacteria and endosymbionts (Wolbachia, Mesoplasma, and Spiroplasma). Our results suggest that garden-associated bacteria are mainly horizontally acquired as the bacterial communities of pellets shared few bacterial taxa with the mature gardens of the four ant species investigated. While the bacterial communities of garden pellets showed some species-specificity, a subset of prevalent bacterial taxa were shared across ant species. Further, our findings provide evidence for vertical transmission of species-specific endosymbiotic bacteria through a transovarial route and/or via fecal droplets. Overall, while we found mixed evidence for vertical transmission of garden bacteria, our results support maternal transmission as a primary route for gut-associated symbionts. While our results suggest that vertical transmission of fungus-growing ant bacterial associates is mediated by the ant hosts, the mechanism behind this host control is not yet understood.

microbiology↗

bioRxiv2017

Physical epistatic landscape of antibody binding affinity

Affinity maturation produces antibodies that bind antigens with high specificity by accumulating mutations in the antibody sequence. Mapping out the antibody-antigen affinity landscape can give us insight into the accessible paths during this rapid evolutionary process. By developing a carefully controlled null model for noninteracting mutations, we characterized epistasis in affinity measurements of a large library of antibody variants obtained by Tite-Seq, a recently introduced Deep Mutational Scan method yielding physical values of the binding constant. We show that representing affinity as the binding free energy minimizes epistasis. Yet, we find that epistatically interacting sites contribute substantially to binding. In addition to negative epistasis, we report a large amount of beneficial epistasis, enlarging the space of high-affinity antibodies as well as their mutational accessibility. These properties suggest that the degeneracy of antibody sequences that can bind a given antigen is enhanced by epistasis -- an important property for vaccine design.

biophysics↗