Biology subjects

Strader, M.

Publications and source records attributed to Strader, M..

3 recordsLinked to original sources

bioRxiv2018

Epigenetic factors coordinate intestinal development

Intestinal epithelium development depends on epigenetic modifications, but whether that is also the case for other intestinal tract cell types remains unclear. We found that functional loss of a DNA methylation machinery component, ubiquitin-like protein containing PHD and RING finger domains 1 (uhrf1), leads to reduced enteric neuron number, changes in neuronal morphology, and severe intestinal smooth muscle disruption. Genetic chimeras revealed that Uhrf1 functions both cell-autonomously in enteric neuron progenitors and cell-non-autonomously in surrounding intestinal cells. Uhrf1 recruits the DNA methyltransferase Dnmt1 to unmethylated DNA during replication. Dnmt1 is also expressed in enteric neuron and smooth muscle progenitors. dnmt1 mutants show a strong reduction in enteric neuron number and disrupted intestinal smooth muscle. Because dnmt1;uhrf1 double mutants have a similar phenotype to dnmt1 and uhrf1 single mutants, Dnmt1 and Uhrf1 must function together during enteric neuron and intestinal muscle development. This work shows that genes controlling epigenetic modifications are important in coordinating intestinal tract development, provides the first demonstration that these genes are important in ENS development, and advances uhrf1 and dnmt1 as potential new Hirschsprung disease candidates.\n\nSummaryThis work provides evidence that DNA methylation factors are important in all cell types that contribute to development of a functional intestine.

developmental biology↗

bioRxiv2018

Effects of thermal stress on amount, composition, and antibacterial properties of coral mucus

The surface mucus layer of reef-building corals supports several essential functions including feeding, sediment clearing, and protection from pathogenic invaders. For the reef ecosystem, coral mucus provides energy to support heterotrophic benthic communities. Mucus production represents a substantial metabolic investment on behalf of the coral: as much as half of the fixed carbon supplied by the corals algal symbionts is incorporated into expelled mucus. In this study, we examined if bleaching (disruption of the coral-algal symbiosis) has the potential to indirectly disturb reef ecosystem function by impacting the nutritional composition of coral mucus. In a controlled laboratory thermal stress challenge, visibly paled corals produced mucus with higher protein and lipid content and increased antibacterial activity relative to healthy corals. These results are likely explained by the expelled symbionts in the mucus of bleached individuals. This study illuminates how the immediate effects of coral bleaching could impact the reef-ecosystem indirectly through modulation of available nutrients within the ecosystem.

molecular biology↗

bioRxiv2018

Relationship between Acropora millepora juvenile fluorescence and composition of newly established Symbiodinium assemblage

Coral-dinoflagellate symbiosis is the key biological interaction enabling existence of modern-type coral reefs, but the mechanisms regulating initial host-symbiont attraction, recognition and symbiont proliferation thus far remain largely unclear. A common reef-building coral, Acropora millepora, displays conspicuous fluorescent polymorphism during all phases of its life cycle, due to the differential expression of fluorescent proteins (FPs) of the green fluorescent protein family. In this study, we examine whether fluorescent variation in young coral juveniles exposed to natural sediments is associated with the uptake of disparate Symbiodinium assemblages determined using ITS-2 deep sequencing. We found that Symbiodinium assemblages varied significantly when redness values varied, specifically in regards to abundances of clades A and C. Whether fluorescence was quantified as a categorical or continuous trait, clade A was found at higher abundances in redder juveniles. These preliminary results suggest juvenile fluorescence may be associated with Symbiodinium uptake, potentially acting as either as an attractant to ecologically specific types or as a mechanism to modulate the internal light environment to control Symbiodinium physiology within the host.

ecology↗