The use of experimentally evolved coral photosymbionts for reef restoration.

The heat tolerance of corals is largely determined by their microbial photosymbionts (Symbiodiniaceae, colloquially known as zooxanthellae). Therefore, manipulating symbiont communities may enhance the ability of corals to survive summer heatwaves. Although heat-tolerant and -sensitive symbiont species occur in nature, even corals that harbour naturally tolerant symbionts have been observed to bleach during summer heatwaves. Experimental evolution (i.e., laboratory selection) of Symbiodiniaceae cultures under elevated temperatures has been successfully used to enhance their upper thermal tolerance, both in vitro and, in some instances, following their reintroduction into corals. In this review, we present the state of this intervention and its potential role within coral reef restoration, and discuss the next critical steps required to bridge the gap to implementation.

Analysis of the Healthy Platelet Proteome Identifies a New Form of Domain-Specific O-Fucosylation.

Platelet activation induces the secretion of proteins that promote platelet aggregation and inflammation. However, detailed analysis of the released platelet proteome is hampered by platelets' tendency to preactivate during their isolation and a lack of sensitive protocols for low abundance releasate analysis. Here, we detail the most sensitive analysis to date of the platelet releasate proteome with the detection of >1300 proteins. Unbiased scanning for posttranslational modifications within releasate proteins highlighted O-glycosylation as being a major component. For the first time, we detected O-fucosylation on previously uncharacterized sites including multimerin-1 (MMRN1), a major alpha granule protein that supports platelet adhesion to collagen and is a carrier for platelet factor V. The N-terminal elastin microfibril interface (EMI) domain of MMRN1, a key site for protein-protein interaction, was O-fucosylated at a conserved threonine within a new domain context. Our data suggest that either protein O-fucosyltransferase 1, or a novel protein O-fucosyltransferase, may be responsible for this modification. Mutating this O-fucose site on the EMI domain led to a >50% reduction of MMRN1 secretion, supporting a key role of EMI O-fucosylation in MMRN1 secretion. By comparing releasates from resting and thrombin-treated platelets, 202 proteins were found to be significantly released after high-dose thrombin stimulation. Complementary quantification of the platelet lysates identified >3800 proteins, which confirmed the platelet origin of releasate proteins by anticorrelation analysis. Low-dose thrombin treatment yielded a smaller subset of significantly regulated proteins with fewer secretory pathway enzymes. The extensive platelet proteome resource provided here (larancelab.com/platelet-proteome) allows identification of novel regulatory mechanisms for drug targeting to address platelet dysfunction and thrombosis.