Marine Protected Areas effectively maintain endemic Pinna nobilis populations

Coastal habitat degradation compromise sessile marine species. Populations of the endemic species, fan shell bivalve Pinna nobilis are declining in spite of species protection. Models analyzed environmental versus human-derived stressors as explanatory variables depicting populations at mesoscale level. Human stressors explained most variability in density spatial distribution significantly disturbing benthic communities, while habitat protection affected P. nobilis structure and physical aggression by anchoring highly impact on densities. Environmental variables played a secondary role, indicating that global change processes are not so relevant in coastal benthic communities as human-derived impacts

Heat shock results in cell cycle delay and synchronisation of mitotic domains in cellularised Drosophila melanogaster embryos

Cells of Drosophila embryos that are subjected to a 37 degrees C temperature shock whilst undergoing the S-phase of cell cycle 14 arrest with their microtubules in an interphase-like state, and with nuclei showing unusual chromatin condensation. They do not recover from this state within a 30 minute period even though extensive gastrulation movements can occur. Cells of embryos heat shocked in G2-phase are delayed in interphase with high levels of cyclins A and B. Within ten minutes recovery from heat shock, cells enter mitosis throughout the embryo. The degradation of the mitotic cyclins A and B in these synchronised mitotic domains does not follow the normal timing, but is delayed. These findings point to a need for caution when interpreting experiments that use the heat shock promoter to study the expression of cell cycle control genes in Drosophila

Heat shock results in cell cycle delay and synchronisation of mitotic domains in cellularised Drosophila melanogaster embryos

Cells of Drosophila embryos that are subjected to a 37 degrees C temperature shock whilst undergoing the S-phase of cell cycle 14 arrest with their microtubules in an interphase-like state, and with nuclei showing unusual chromatin condensation. They do not recover from this state within a 30 minute period even though extensive gastrulation movements can occur. Cells of embryos heat shocked in G2-phase are delayed in interphase with high levels of cyclins A and B. Within ten minutes recovery from heat shock, cells enter mitosis throughout the embryo. The degradation of the mitotic cyclins A and B in these synchronised mitotic domains does not follow the normal timing, but is delayed. These findings point to a need for caution when interpreting experiments that use the heat shock promoter to study the expression of cell cycle control genes in Drosophila

Mauve/LYST limits fusion of lysosome-related organelles and promotes centrosomal recruitment of microtubule nucleating proteins.

Lysosome-related organelles (LROs) are endosomal compartments carrying tissue-specific proteins, which become enlarged in Chediak-Higashi syndrome (CHS) due to mutations in LYST. Here, we show that Drosophila Mauve, a counterpart of LYST, suppresses vesicle fusion events with lipid droplets (LDs) during the formation of yolk granules (YGs), the LROs of the syncytial embryo, and opposes Rab5, which promotes fusion. Mauve localizes on YGs and at spindle poles, and it co-immunoprecipitates with the LDs' component and microtubule-associated protein Minispindles/Ch-TOG. Minispindles levels are increased at the enlarged YGs and diminished around centrosomes in mauve-derived mutant embryos. This leads to decreased microtubule nucleation from centrosomes, a defect that can be rescued by dominant-negative Rab5. Together, this reveals an unanticipated link between endosomal vesicles and centrosomes. These findings establish Mauve/LYST's role in regulating LRO formation and centrosome behavior, a role that could account for the enlarged LROs and centrosome positioning defects at the immune synapse of CHS patients

Residuos en el mar Balear

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Amphipods associated on the algal and debris communities with the presence of invasive algae Lophocladia lallemandii sa Dragonera Natural Park (Balearic Islands)

En el litoral Balear es troben comunitats d’algues fotòfiles associades a fons rocosos. Es tracta d’un dels ecosistemes més representats a l’infralitoral i que són objecte d’un gran nombre d’impactes, com és la colonització d’espècies invasores, entre les que destaca l’alga Lophocladia lallemandii. Aquesta espècie no només altera les comunitats d’algues sinó que també, en les zones amb un baix hidrodinamisme, forma grans acumulacions de detritus, que en molts casos superen en biomassa a les algues i fanerògames locals. Aquests dos hàbitats sostenen comunitats d’amfípodes que són uns bioindicadors molt eficaços dels canvis produït en els medi. En el present estudi entre les mostres de detritus i dels fons rocosos s’han identificat 43 espècies d’amfípodes que pertanyen a 20 famílies. La majoria de mostres identificades són pròpies de fons rocosos i, en el cas dels cúmuls detrítics, apareixen espècies característiques d’aquest hàbitat. Les màximes abundàncies pels amfípodes es donen en el període hivernal. Les espècies classificades mostren diferents valors en el nombre d’individus segons es tracti de zones envaïdes per L. lallemandii o zones control. Aquest efecte pot afavorir determinades espècies i fer disminuir les abundàncies d’altres quan l’alga invasora s’estableix. Les mostres realitzades a l’estiu en fons rocosos a partir de quadrants 20x20 cm i amb la presència de L. lallemandii, presenten unes majors abundàncies i riquesa específica que les zones control. Contràriament, en les mostres obtingudes amb la utilització de la xarxa de mà 40x20cm, els resultats indiquen majors abundàncies i un nombre major d’espècies que les zones control durant el període estival. Aquest efecte és producte de la colonització de l’hàbitat per part de L. lallemandii que genera canvis estructurals en les comunitats algals i que poden repercutir en les taxes de predació a diferents nivells dins de la comunitat. L’efecte d’aquestes algues invasores dins l’ecosistema ha de ser estudiat a llarg termini per determinar si els canvis produïts en els ecosistemes es mantenen en el temps.In the Balearic coastline there are photophile seaweed communities associated with rocky bottom. It is one of the largest ecosystems and it’s subject to a great number of impacts, such as the arrival of invasive species, among which there’s Lophocladia lallemandii. This species not only alters the communities of algae, but also in areas with low hydrodynamics, it forms large accumulations of debris, which often exceed the algal biomass and local phanerogams. These two habitats sustain communities of amphipods that are very effective bioindicators of changes occurred in the environment. In the present study, among the samples of detritus and of the rocky bottoms, 43 species of amphipods that belong to 20 families have been identified. The majority of identified samples are typical of rocky bottoms and in the case of detrital sediment load, characteristic species of this habitat turn up. The maximum abundance for amphipods in the study are given in the winter. Classified species show different values in the number of individuals in the case of areas invaded by L. lallemandii or control areas. This effect may favour certain species and reduce the abundance of others in case the invading seaweed settles. The samples carried out in the summer in rocky bottoms from 20x20cm quadrants and with the presence of L. lallemandii, present higher abundances and species richness than the control zones. By contrast, in the samples obtained with the use of the 40X20cm hand net, results indicate that the control zones during the summer show higher abundances and species richness. This effect is a result of the colonization of the habitat by L. lallemandii which generates structural changes in algal communities that may affect the rates of predation at different levels within the community. The effect of these invasive algae in the ecosystem must be studied long term to determine whether changes in ecosystems are maintained over time

Applying Fourier analyses to assess influence of environmental factors on shell morphology of Mediterranean endemic bivalve Pinna nobilis

Environmental factors such as depth or hydrodynamics can influence the morphology of Pinna nobilis. In the present work the variation in shape morphology was studied by Fourier analysis according to different environmental conditions. Important differences were found within juveniles and adults. Discriminant analysis with elliptical Fourier descriptors was able to classify with high accuracy 97.1% of the individuals according to the factors studie

Spatial distribution of macro- and micro-litter items along rocky and sandy beaches of a Marine Protected Area in the western Mediterranean Sea

In this study, the spatial distribution and physical characteristics of beach macro- and micro-litter within the Cabrera Archipelago Maritime-Terrestrial National Park (Cabrera MPA), in the Balearic Islands have been analysed. For macro-litter items, a mean concentration of 1.9 ± 2.4 items/m2 weighing a total of 13 kg was quantified. In terms of beach composition, cobble beaches with deposited seagrass had almost twice as much marine litter as other beaches. For beach micro-litter items, white and transparent microplastics within the size class of 1–2 mm were the most abundant on all the beaches, and the most common polymer types were polyethylene (64%) and polypropylene (17.2%). Overall, for both macro- and micro-litter items, plastic was the most dominant material (90%) identified on all beaches surveyed within Cabrera MPA, indicating areas of low anthropogenic pressures are increasingly becoming sinks for marine litter.En prens