Untersuchung zur Spezies-spezifischen Regulation von Nekroptose durch Caspasen in humanen U-937-Zellen

Nachdem sich herausgestellt hatte, dass nicht nur Apoptose als genetisch regulierter Zelltod ablaufen kann, wurde 2005 die Nekroptose beschrieben, die heute als am besten untersuchte Form des programmierten, nicht apoptotischen, Zelltods gilt. Lange Zeit galt die Annahme, dass Caspase-8, als entscheidende Initiatorcaspase der Apoptose, vor Nekroptose schützt, da auch gezeigt werden konnte, dass Mäuseembryonen, bei denen Caspase-8 ausgeschaltet wurde, bereits vor der Geburt, aufgrund einer gesteigerten Nekroptose, verstarben. Anders als erwartet, hatte sich bereits in Pilotexperimenten gezeigt, dass in menschlichen Zellen nicht die Herunterregulierung von Caspase-8, sondern die von Caspase-10, welche in Mäusen evolutionär verloren ging, zu einer gesteigerten Nekroptoserate führt. Zusammenfassend liefert die vorliegende Arbeit Belege für Spezies-spezifische Unterschiede von Caspase-8 in Bezug auf die Nekroptose bei Maus und Mensch und die Rolle von Caspase-10 für die Regulation der Nekroptose im Menschen. Ein genaues Verständnis dieser Zusammenhänge wird in Zukunft immer wichtiger werden, um gezielt z.B. Nekroptose-assoziierte Erkrankungen behandeln zu können

Consequences of marine barriers for genetic diversity of the coral-specialist yellowbar angelfish from the Northwestern Indian Ocean

© 2019 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. Ocean circulation, geological history, geographic distance, and seascape heterogeneity play an important role in phylogeography of coral-dependent fishes. Here, we investigate potential genetic population structure within the yellowbar angelfish (Pomacanthus maculosus) across the Northwestern Indian Ocean (NIO). We then discuss our results with respect to the above abiotic features in order to understand the contemporary distribution of genetic diversity of the species. To do so, restriction site-associated DNA sequencing (RAD-seq) was utilized to carry out population genetic analyses on P. maculosus sampled throughout the species’ distributional range. First, genetic data were correlated to geographic and environmental distances, and tested for isolation-by-distance and isolation-by-environment, respectively, by applying the Mantel test. Secondly, we used distance-based and model-based methods for clustering genetic data. Our results suggest the presence of two putative barriers to dispersal; one off the southern coast of the Arabian Peninsula and the other off northern Somalia, which together create three genetic subdivisions of P. maculosus within the NIO. Around the Arabian Peninsula, one genetic cluster was associated with the Red Sea and the adjacent Gulf of Aden in the west, and another cluster was associated with the Arabian Gulf and the Sea of Oman in the east. Individuals sampled in Kenya represented a third genetic cluster. The geographic locations of genetic discontinuities observed between genetic subdivisions coincide with the presence of substantial upwelling systems, as well as habitat discontinuity. Our findings shed light on the origin and maintenance of genetic patterns in a common coral reef fish inhabiting the NIO, and reinforce the hypothesis that the evolution of marine fish species in this region has likely been shaped by multiple vicariance events

Ice ages and butterflyfishes: Phylogenomics elucidates the ecological and evolutionary history of reef fishes in an endemism hotspot

For tropical marine species, hotspots of endemism occur in peripheral areas furthest from the center of diversity, but the evolutionary processes that lead to their origin remain elusive. We test several hypotheses related to the evolution of peripheral endemics by sequencing ultraconserved element (UCE) loci to produce a genome-scale phylogeny of 47 butterflyfish species (family Chaetodontidae) that includes all shallow water butterflyfish from the coastal waters of the Arabian Peninsula (i.e., Red Sea to Arabian Gulf) and their close relatives. Bayesian tree building methods produced a well-resolved phylogeny that elucidated the origins of butterflyfishes in this hotspots of endemism. We show that UCEs, often used to resolve deep evolutionary relationships, represent an important tool to assess the mechanisms underlying recently diverged taxa. Our analyses indicate that unique environmental conditions in the coastal waters of the Arabian Peninsula probably contributed to the formation of endemic butterflyfishes. Older endemic species are also associated with narrow versus broad depth ranges, suggesting that adaptation to deeper coral reefs in this region occurred only recently (<1.75 Ma). Even though deep reef environments were drastically reduced during the extreme low sea level stands of glacial ages, shallow reefs persisted, and as such there was no evidence supporting mass extirpation of fauna in this region

On the origin of endemic species in the Red Sea

Aim: The geological and palaeo-climatic forces that produced the unique biodiversity in the Red Sea are a subject of vigorous debate. Here, we review evidence for and against the hypotheses that: (1) Red Sea fauna was extirpated during glacial cycles of the Pleistocene and (2) coral reef fauna found refuge within or just outside the Red Sea during low sea level stands when conditions were inhospitable. Location: Red Sea and Western Indian Ocean. Methods: We review the literature on palaeontological, geological, biological and genetic evidence that allow us to explore competing hypotheses on the origins and maintenance of shallow-water reef fauna in the Red Sea. Results: Palaeontological (microfossil) evidence indicates that some areas of the central Red Sea were devoid of most plankton during low sea level stands due to hypersaline conditions caused by almost complete isolation from the Indian Ocean. However, two areas may have retained conditions adequate for survival: the Gulf of Aqaba and the southern Red Sea. In addition to isolation within the Red Sea, which separated the northern and southern faunas, a strong barrier may also operate in the region: the cold, nutrient-rich water upwelling at the boundary of the Gulf of Aden and the Arabian Sea. Biological data are either inconclusive or support these putative barriers and refugia, but no data set, that we know of rejects them. Genetic evidence suggests that many endemic lineages diverged from their Indian Ocean counterparts long before the most recent glaciations and/or are restricted to narrow areas, especially in the northern Red Sea. Main conclusions: High endemism observed in the Red Sea and Gulf of Aden appears to have multiple origins. A cold, nutrient-rich water barrier separates the Gulf of Aden from the rest of the Arabian Sea, whereas a narrow strait separates the Red Sea from the Gulf of Aden, each providing potential isolating barriers. Additional barriers may arise from environmental gradients, circulation patterns and the constriction at the mouth of the Gulf of Aqaba. Endemics that evolved within the Red Sea basin had to survive glacial cycles in relatively low salinity refugia. It therefore appears that the unique conditions in the Red Sea, in addition to those characteristics of the Arabian Peninsula region as a whole, drive the divergence of populations via a combination of isolation and selection

A review of contemporary patterns of endemism for shallow water reef fauna in the Red Sea

Aim: The Red Sea is characterised by a unique fauna and historical periods of desiccation, hypersalinity and intermittent isolation. The origin and contemporary composition of reef-associated taxa in this region can illuminate biogeographical principles about vicariance and the establishment (or local extirpation) of existing species. Here we aim to: (1) outline the distribution of shallow water fauna between the Red Sea and adjacent regions, (2) explore mechanisms for maintaining these distributions and (3) propose hypotheses to test these mechanisms. Location: Red Sea, Gulf of Aden, Arabian Sea, Arabian Gulf and Indian Ocean. Methods: Updated checklists for scleractinian corals, fishes and non-coral invertebrates were used to determine species richness in the Red Sea and the rest of the Arabian Peninsula and assess levels of endemism. Fine-scale diversity and abundance of reef fishes within the Red Sea were explored using ecological survey data. Results: Within the Red Sea, we recorded 346 zooxanthellate and azooxanthellate scleractinian coral species of which 19 are endemic (5.5%). Currently 635 species of polychaetes, 211 echinoderms and 79 ascidians have been documented, with endemism rates of 12.6%, 8.1% and 16.5% respectively. A preliminary compilation of 231 species of crustaceans and 137 species of molluscs include 10.0% and 6.6% endemism respectively. We documented 1071 shallow fish species, with 12.9% endemic in the entire Red Sea and 14.1% endemic in the Red Sea and Gulf of Aden. Based on ecological survey data of endemic fishes, there were no major changes in species richness or abundance across 1100 km of Saudi Arabian coastline. Main conclusions: The Red Sea biota appears resilient to major environmental fluctuations and is characterized by high rates of endemism with variable degrees of incursion into the Gulf of Aden. The nearby Omani and Arabian Gulfs also have variable environments and high levels of endemism, but these are not consistently distinct across taxa. The presence of physical barriers does not appear to explain species distributions, which are more likely determined by ecological plasticity and genetic diversity

Fish Intelligence, Sentience and Ethics

Fish are one of the most highly utilised vertebrate taxa by humans; they are harvested from wild stocks as part of global fishing industries, grown under intensive aquaculture conditions, are the most common pet and are widely used for scientific research. But fish are seldom afforded the same level of compassion or welfare as warm-blooded vertebrates. Part of the problem is the large gap between people’s perception of fish intelligence and the scientific reality. This is an important issue because public perception guides government policy. The perception of an animal’s intelligence often drives our decision whether or not to include them in our moral circle. From a welfare perspective, most researchers would suggest that if an animal is sentient, then it can most likely suffer and should therefore be offered some form of formal protection. There has been a debate about fish welfare for decades which centres on the question of whether they are sentient or conscious. The implications for affording the same level of protection to fish as other vertebrates are great, not least because of fishing-related industries. Here, I review the current state of knowledge of fish cognition starting with their sensory perception and moving on to cognition. The review reveals that fish perception and cognitive abilities often match or exceed other vertebrates. A review of the evidence for pain perception strongly suggests that fish experience pain in a manner similar to the rest of the vertebrates. Although scientists cannot provide a definitive answer on the level of consciousness for any nonhuman vertebrate, the extensive evidence of fish behavioural and cognitive sophistication and pain perception suggests that best practice would be to lend fish the same level of protection as any other vertebrate

See- und Süßwasserfische von Sumatra und Java

Durch die Herren Dr. EDUARD und HANS-RUDOLF SCHMIDT, Tropicarium Frankfurt am Main, erhielt das Senckenberg-Museum eine Reihe von See- und Süßwasserfischen, die im folgenden kurz dargestellt werden. Eine Art der Gattung Chaerodon sowie eine Unterart von Parosphromenus deissneri werden neu beschrieben. Auffällige Abweichungen der untersuchten Fische von den bisherigen Darstellungen und Beschreibungen werden durch Zeichnungen veranschaulicht

Die physiographische Zonierung der Saumriffe von Sarso : 4. Beitrag der Arbeitsgruppe Litoralforschung

1. The physiographical zones of the coast of the islands Sarso and Sindi Sarso (Farsan Archipelago, Red Sea) were analyzed by 3 profiles. As shore types a steep coast with an eroded eulitoral platform, a steep coast without such a platform and a sandbeach were selected. 2. The most conspicuous and characteristic fishes, invertebrates and algae were identified, their distribution and zonational limit were studied. 3. In contrast to a normal fringing reef the whole litoral area of these islands is of coral origin. The islands themselves are raised subfossil reefs from the early pleistocene or late tertiary. The recent reefs are based on eroded platforms of these subfossil reefs. 4. Terrestially and subaquatically there are distinguishable different water level marks. They may be the result not only of tectonic occurrences, but also of eustatic changes of the sea-level by glacial origin. 5. The litoral area along the NE coast of the island Sarso was mapped. The 3 zones were studied and described as cross-sections. 6. Samples of the characteristic lime stone of different zones were studied and identified as of only corallogene. 7. As profile II is distinguished from profile I only by the sedimentation of sand upon the eroded platform along the beach there arc great morphological and ecological differences between profile I and III. 8. A reconstruction of the reef development of profiles I and III by raising sea-level was tried. Despite the morphological differences there are many important geological coincidences

Forcipiger longirostris und Chaetodon leucopleura (Pisces, Perciformes, Chaetodontidae), zwei Neunachweise für das Rote Meer, und einige zoogeographische Probleme der Rotmeer-Fische : 9. Beitrag der Arbeitsgruppe Litoralforschung

During the first Meteor-Expedition two species of fish, hitherto unrecorded in the Red Sea, were colected near the Island Sarso (Farsan Archipelago): Forcipiger longirostris (BROUSSONET) and Chaetodon lettcoplettra GÜNTHER & PLAYFAIR. As both are identical with specimens from the Indian Ocean and as their distribution within the Red Sea is limited to the far South, it is concluded that these two species are postglacial immigrants. Besides this small group of immigrants, the majority of the endemic Red Sea species appear to be preglacial immigrants from the Indian Ocean. A few other species seem to be of Mediterranean Tethys origin from the middle or early tertiary