bioRxiv Science⌕ Search

Biology subjects

McFadden, S.

Publications and source records attributed to McFadden, S..

2 recordsLinked to original sources

Sexual dimorphic responses of C57BL/6 mice to Fisetin or Dasatinib and Quercetin cocktail oral treatment

Senolytic treatment in aged mice clears senescent cell burden leading to functional improvements. However, less is known regarding the effects of these compounds when administered prior to significant senescent cell accumulation. From 4-13 months of age, C57BL/6 male and female mice received monthly oral dosing of either 100 mg/kg Fisetin or a 5 mg/kg Dasatinib (D) plus 50 mg/kg Quercetin (Q) cocktail. During treatment, several aspects of healthy aging were assayed including glucose metabolism using an insulin and glucose tolerance test, cognitive performance using Morris water maze and novel object recognition, and energy metabolism using indirect calorimetry. Afterwards, mice were euthanized for plasma and tissue specific markers of senescence-associated secretory phenotype (SASP) and white adipose tissue accumulation (WAT). Sexually dimorphic treatment effects were observed. Fisetin treated male mice had reduced SASP, enhanced glucose and energy metabolism, improved cognitive performance, and increased mRNA expression of adiponectin receptor 1 and glucose transporter 4. D+Q treatment had minimal effects in male C57BL/6 mice, but was detrimental to females causing increased SASP expression along with accumulation of WAT depots. Reduced energy metabolism and cognitive performance were also noted. Fisetin treatment had no effect in female C57BL/6 mice potentially due to a slower rate of biological aging. In summary, the senolytic treatment in young adulthood, has beneficial, negligible, or detrimental effects in C57BL/6 mice dependent upon sex and treatment. These observations should serve as a note of caution in this rapidly evolving and expanding field of investigation. Graphical AbstractMale and female C57BL/6 mice were treated with once monthly oral doses of either Dasatinib (D) + Quercetin (Q) or Fisetin from 4-13 months of age. Females treated with D+Q had increased adiposity and SASP markers (red spheres) along with decreased metabolism (blue flame) and cognitive performance. Males treated with Fisetin had reduced SASP markers (blue spheres) as well as improved metabolism (red flame) and cognition. No effects were observed in females treated with Fisetin or males treated with D+Q. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=126 SRC="FIGDIR/small/467509v2_ufig1.gif" ALT="Figure 1"> View larger version (25K): org.highwire.dtl.DTLVardef@1d7f450org.highwire.dtl.DTLVardef@e8b32forg.highwire.dtl.DTLVardef@14be597org.highwire.dtl.DTLVardef@1ce31af_HPS_FORMAT_FIGEXP M_FIG C_FIG

physiology↗

A chromosomal inversion drives evolution of multiple adaptive traits in deer mice

A long-standing question in evolutionary biology is how differences in multiple traits can evolve quickly and be maintained together during local adaptation. Using forest and prairie ecotypes in deer mice, which differ in both tail length and coat color, we discovered a 41 Mb chromosomal inversion that is strongly linked to variation in both traits. The inversion maintains highly divergent loci in strong linkage disequilibrium and likely originated ~170 kya, long before the forest-prairie divergence ~10 kya. Consistent with a role in local adaptation, inversion frequency is associated with phenotype and habitat across both a local transect and the species range. Still, although eastern and western forest subspecies share similar phenotypes, the inversion is absent in eastern North America. This work highlights the significance of inversion polymorphisms for the establishment and maintenance of multiple locally adaptive traits in mammals, and demonstrates that, even within a species, parallel phenotypes may evolve through nonparallel genetic mechanisms.

evolutionary biology↗