Éditeur(s) : HAL CCSD Landes Bioscience
Résumé : International audience
In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
Autophagy

hal-00735751
https://hal.archives-ouvertes.fr/hal-00735751
PUBMED : 22966490

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
The Western Indian Ocean harbors one of theworld’s most diverse marine biota yet is threatened byexploitation with few conservation measures in place.Primary candidates for conservation in the region are theScattered Islands (Iles Eparses), a group of relativelypristine and uninhabited islands in the MozambiqueChannel. However, while optimal conservation strategiesdepend on the degree of population connectivity amongspatially isolated habitats, very few studies have beenconducted in the area. Here, we use highly variablemicrosatellite markers from two damselfishes (Amphiprionakallopisos and Dascyllus trimaculatus) with differing lifehistory traits [pelagic larval duration (PLD), adult habitat]to compare genetic structure and connectivity among theseislands using classic population structure indices as well asBayesian clustering methods. All classical fixation indexesFST, RST, G0ST, and Jost’s D show stronger genetic differentiationamong islands for A. akallopisos compared to D.trimaculatus, consistent with the former species’ shorterPLD and stronger adult site attachment, which may restrictlarval dispersal potential. In agreement with these results,the Bayesian analysis revealed clear genetic differentiationamong the islands in A. akallopisos, separating the southerngroup (Bassas da India and Europa) from the center(Juan de Nova) and northern (Iles Glorieuses) islands, butnot for D. trimaculatus. Local oceanographic patterns suchas eddies that occur along the Mozambique Channel appearto parallel the results reported for A. akallopisos, but suchfeatures seem to have little effect on the genetic differentiationof D. trimaculatus. The contrasting patterns ofgenetic differentiation between species within the samefamily highlight the importance of accounting for diverselife history traits when assessing community-wide connectivity,an increasingly common consideration in conservationplanning.
ISSN: 0722-4028

hal-01561992
https://hal-univ-perp.archives-ouvertes.fr/hal-01561992
DOI : 10.1007/s00338-016-1495-z