Biology subjects

Robinson, K. M.

Publications and source records attributed to Robinson, K. M..

3 recordsLinked to original sources

bioRxiv2026

Division of labor and low temperatures predict geographic variation in thermal tolerance of a North American paper wasp (Mischocyttarus mexicanus cubicola)

The biogeographic study of organismal thermal performance is fundamental to our understanding of how climate drives evolution. However, despite highly social insects being popular models for such studies, biogeographic comparisons of thermal functional traits seldom consider division of labor. Individuals within cooperative societies can operate in different microclimates, exposing different task groups to different selection pressures. Here we present a study of how thermal tolerance limits in a social paper wasp vary broadly across temperate and subtropical climates in eastern North America, testing whether division of labor between foundresses and non-reproductive workers generates adaptive variation in thermal performance within the colony. Cold tolerance rather than heat tolerance varied more predictably with environmental temperatures across latitudes, with temperate populations experiencing bouts of winter cold coma, unlike in subtropical populations. Within colonies, reproductive foundresses were also more cold-tolerant than workers, enabling them to remain mobile at cooler periods of early spring during crucial tasks of nest construction, before workers emerge. Together, these results broaden our understanding of how climate shapes thermal performance on both biogeographic and social scales.

ecology↗

bioRxiv2018

Transcriptomic characterization of signaling pathways associated with osteoblastic differentiation of MC-3T3E1 cells

Bone remodeling involves the coordinated actions of osteoclasts, which resorb the calcified bony matrix, and osteoblasts, which refill erosion pits created by osteoclasts to restore skeletal integrity and adapt to changes in mechanical load. Osteoblasts are derived from pluripotent mesenchymal stem cell precursors, which undergo differentiation under the influence of a host of local and environmental cues. To characterize the autocrine/paracrine signaling networks associated with osteoblast maturation and function, we performed gene network analysis using complementary \"agnostic\" DNA microarray and \"targeted\" NanoString nCounter datasets derived from murine MC3T3-E1 cells induced to undergo synchronized osteoblastic differentiation in vitro. Pairwise datasets representing changes in gene expression associated with growth arrest (day 2 to 5 in culture), differentiation (day 5 to 10 in culture), and osteoblast maturation (day 10 to 28 in culture) were analyzed using Ingenuity Systems Pathways Analysis to generate predictions about signaling pathway activity based on the temporal sequence of changes in target gene expression. Our data indicate that some pathways known to be involved in osteoblast differentiation, e.g. Wnt/{beta}-catenin signaling, are most active early in the process, while others, e.g. TGF{beta}/BMP, cytokine/JAK-STAT and TNF/RANKL signaling, increase in activity as differentiation progresses. Collectively, these pathways contribute to the sequential expression of genes involved in the synthesis and mineralization of extracellular matrix. These results provide insight into the temporal coordination and complex interplay between signaling networks controlling gene expression during osteoblast differentiation. A more complete understanding of these processes may aid the discovery of novel methods to promote osteoblast development for the treaent of conditions characterized by low bone mineral density.

cell biology↗

bioRxiv2017

Natural variation at FLOWERING LOCUS T2 mediates local adaptation in a key life history trait in European aspen

BackgroundThe initiation of growth cessation and dormancy represent critical life-history tradeoffs between survival and growth, and have important fitness effects in perennial plants. Such adaptive life history traits often show strong local adaptation along environmental gradients but despite their importance, the genetic architecture of these traits remains poorly understood.\n\nResultsWe integrate whole genome re-sequencing with environmental and phenotypic data from common garden experiments to investigate the genomic basis of local adaptation across a latitudinal gradient in European aspen (Populus tremula). We discover a single genomic region containing the PtFT2 gene that mediates local adaptation in the timing of bud set and that explains 65% of the observed genetic variation in bud set. This locus is the likely target of a recent selective sweep that originated right before or during colonization of northern Scandinavia following the last glaciation. Field and greenhouse experiments confirm that variation in PtFT2 gene expression affect the phenotypic variation in bud set that we observe in wild natural populations.\n\nConclusionsOur results reveal a major effect locus that determine the timing of bud set and that have facilitated rapid adaptation to shorter growing seasons and colder climates in European aspen. The discovery of a single locus explaining a substantial fraction of the variation in a key life history trait is remarkable given that such traits are generally considered to be highly polygenic. These findings provide a dramatic illustration of how loci of large-effect for adaptive traits can arise and be maintained over large geographical scales in natural populations.

evolutionary biology↗