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Environmental context Corals produce copious amounts of dimethylsulfoniopropionate (DMSP), a sulfur compound implicated in climate regulation. We studied DMSP concentrations inside corals and unveiled the linkage between DMSP availability and the abundance of DMSP-degrading bacterial groups inhabiting the corals’ surface. Our findings suggest that DMSP mediates the interplay between corals and microbes, highlighting the importance of sulfur compounds for microbial processes in corals and for the resilience of coral reef ecosystems. Abstract Corals produce copious amounts of dimethylsulfoniopropionate (DMSP), a sulfur compound thought to play a role in structuring coral-associated bacterial communities. We tested the hypothesis that a linkage exists between DMSP availability in coral tissues and the community dynamics of bacteria in coral surface mucus. We determined DMSP concentrations in three coral species (Meandrina meandrites, Porites astreoides and Siderastrea siderea) at two sampling depths (5 and 25m) and times of day (dawn and noon) at Curaçao, Southern Caribbean. DMSP concentration (4–409nmolcm-2 coral surface) varied with host species-specific traits such as Symbiodinium cell abundance, but not with depth or time of sampling. Exposure of corals to air caused a doubling of their DMSP concentration. The phylogenetic affiliation of mucus-associated bacteria was examined by clone libraries targeting three main subclades of the bacterial DMSP demethylase gene (dmdA). dmdA gene abundance was determined by quantitative Polymerase Chain Reaction (qPCR) against a reference housekeeping gene (recA). Overall, a higher availability of DMSP corresponded to a lower relative abundance of the dmdA gene, but this pattern was not uniform across all host species or bacterial dmdA subclades, suggesting the existence of distinct DMSP microbial niches or varying dmdA DMSP affinities. This is the first study quantifying dmdA gene abundance in corals and linking related changes in the community dynamics of DMSP-degrading bacteria to DMSP availability. Our study suggests that DMSP mediates the regulation of microbes by the coral host and highlights the significance of sulfur compounds for microbial processes in coral reefs.

A recessive mutation exhibiting severe myelin breakdown, mainly at the level of the lumbar segments of the spinal cord and without any associated inflammation, was discovered in a partially inbred rat colony. Analysis of the segregation patterns of a set of polymorphic microsatellite markers in two inter-strain crosses allowed the mapping of this autosomal recessive mutation to rat Chromosome (Chr) 17, very close to the prolactin (Prl)locus, in a region homologous to human Chr 6p21.2-22.3 and mouse Chr 13. The pathology of the demyelination process and the chromosomal localization indicate that this mutation has no known equivalent in either mouse or human.

Die Albufereta de Pollença ist eine der typischen Lagunen des westlichen Mittelmeeres, die in einer Vertiefung des Miozäns der Balearischen Inseln liegt. Sie kennzeichnet sich durch salziges und brackiges Marschland mit Lagunen und Kanälen, die durch ein bioklastisches Stranddünensystem vom Meer getrennt sind. Ihr Ausfluß verbindet die Lagune mit dem Meer und bildet so ein Mikrodelta. Die Gezeiten sind belanglos und die meisten morphologischen und dynamischen Prozesse sind mit der Wellenaktivität und den Luftdruckschwankungen verbunden. Die Schwemmprozesse sind sehr unregelmäßig und beschränkt, da sie die Folge des typischen Mittelmeerklimas sind. Es werden acht unterschiedliche Ablagerungsphasen beschrieben, die man als lagunär (dunkelbraune Schluffe mit bioklastischen Resten, konkretionärer grüner Kalkschlamm, graue geschichtete Schluffe, rote terrigene Schluffe und dunkelbraune Schluffe mit Posidonia) und litoral (fein- bis mittelgeschichtete bioklastische Sande, lithoklastische Kiese und feine Sande mit Posidonia) einteilen könnte. Diese Faziestypen beschreiben das System, dessen horizontale und vertikale Verteilung in Verbindung mit der jüngsten quartären Transgression steht.