Suitability of Lychee Fruits On and Off the Tree for Cryptophlebia spp.

Cryptophlebia illepida and C. ombrodelta larval establishment was studied in lychee fruit on and off the tree under field conditions. The proportion of larvae establishing from hatched eggs and the proportion of fruit with at least one larva establishing were significantly higher for C. illepida in fruit detached from the tree compared with fruit on the tree. The trend for C. ombrodelta was toward higher establishment in fruit on the tree compared with fruit detached from the tree but results were not significant. Although lychee is considered a poor host for C. illepida, the threat of introducing this pest in contraband fruit entering the U.S. mainland may be greater than previously thought

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Endogenous fluctuations of OCT4 and SOX2 bias pluripotent cell fate decisions

SOX2 and OCT4 are pioneer transcription factors playing a key role in embryonic stem (ES) cell self‐renewal and differentiation. How temporal fluctuations in their expression levels bias lineage commitment is unknown. Here, we generated knock‐in reporter fusion ES cell lines allowing to monitor endogenous SOX2 and OCT4 protein fluctuations in living cells and to determine their impact on mesendodermal and neuroectodermal commitment. We found that small differences in SOX2 and OCT4 levels impact cell fate commitment in G1 but not in S phase. Elevated SOX2 levels modestly increased neuroectodermal commitment and decreased mesendodermal commitment upon directed differentiation. In contrast, elevated OCT4 levels strongly biased ES cells towards both neuroectodermal and mesendodermal fates in undirected differentiation. Using ATAC‐seq on ES cells gated for different endogenous SOX2 and OCT4 levels, we found that high OCT4 levels increased chromatin accessibility at differentiation‐associated enhancers. This suggests that small endogenous fluctuations of pioneer transcription factors can bias cell fate decisions by concentration‐dependent priming of differentiation‐associated enhancers

Dynamic regulation of chromatin accessibility by pluripotency transcription factors across the cell cycle

The pioneer activity of transcription factors allows for opening of inaccessible regulatory elements and has been extensively studied in the context of cellular differentiation and reprogramming. In contrast, the function of pioneer activity in self-renewing cell divisions and across the cell cycle is poorly understood. Here we assessed the interplay between OCT4 and SOX2 in controlling chromatin accessibility of mouse embryonic stem cells. We found that OCT4 and SOX2 operate in a largely independent manner even at co-occupied sites, and that their cooperative binding is mostly mediated indirectly through regulation of chromatin accessibility. Controlled protein degradation strategies revealed that the uninterrupted presence of OCT4 is required for post-mitotic re-establishment and interphase maintenance of chromatin accessibility, and that highly OCT4-bound enhancers are particularly vulnerable to transient loss of OCT4 expression. Our study sheds light on the constant pioneer activity required to maintain the dynamic pluripotency regulatory landscape in an accessible state

Religions comparées des peuples sans écriture

Lévi-Strauss Claude, Jouin M., Pitt-Rivers Julian, Panoff Françoise, Zems A., Friedman J., Deluz A., Casevitz-Renard France-Marie, Yamaguchi M., Macherel C., Guiart Jean, Bensa A., Weller J., Bidou P., Le Roy Ladurie E., Lassus B., Betthe C., Lartigue F., Perrin Michel, Gasché Jürg, Izard M. Religions comparées des peuples sans écriture. In: Annuaire des sciences religieuses. Annuaire. Tomes 80-81, Fascicule III. Comptes rendus des conférences 1971-1972 et 1972-1973. 1971. pp. 5-19

Religions comparées des peuples sans écriture

Lévi-Strauss Claude, Jouin M., Pitt-Rivers Julian, Panoff Françoise, Zems A., Friedman J., Deluz A., Casevitz-Renard France-Marie, Yamaguchi M., Macherel C., Guiart Jean, Bensa A., Weller J., Bidou P., Le Roy Ladurie E., Lassus B., Betthe C., Lartigue F., Perrin Michel, Gasché Jürg, Izard M. Religions comparées des peuples sans écriture. In: Annuaire des sciences religieuses. Annuaire. Tomes 80-81, Fascicule III. Comptes rendus des conférences 1971-1972 et 1972-1973. 1971. pp. 5-19