DNA methyltransferases and stress-related genes expression in zebrafish larvae after exposure to heat and copper during reprogramming of DNA methylation

DNA methylation, a well-studied epigenetic mark, is important for gene regulation in adulthood and for development. Using genetic and epigenetic approaches, the present study aimed at evaluating the effects of heat stress and copper exposure during zebrafish early embryogenesis when patterns of DNA methylation are being established, a process called reprogramming. Embryos were exposed to 325 μg Cu/L from fertilization (<1 h post fertilization - hpf) to 4 hpf at either 26.5 °C or 34 °C, followed by incubation in clean water at 26.5 °C till 96 hpf. Significant increased mortality rates and delayed hatching were observed following exposure to combined high temperature and Cu. Secondly, both stressors, alone or in combination, significantly upregulated the expression of de novo DNA methyltransferase genes (dnmt3) along with no differences in global cytosine methylation level. Finally, Cu exposure significantly increased the expression of metallothionein (mt2) and heat shock protein (hsp70), the latter being also increased following exposure to high temperature. These results highlighted the sensitivity of early embryogenesis and more precisely of the reprogramming period to environmental challenges, in a realistic situation of combined stressors

Marquette Literary Review, Issue 1, Spring 2009

Table of Contents POETRY ... 2 AVALON THEATER, Amy Schoofs‐Rahne ... 2 ALABASTER, Alex Elliott ... 3 MENTAL SALUTATIONS, Ali Boyd ... 4 MUSSELS, Ian Parker ... 5 UNCERTAIN IS A VERB, Desiree Valentine ... 6 THE FUTURE, Ali Boyd ... 7 THE QUAIL’S HUSBAND, Emilie Eschbacher ... 8 PROGRESS REPORT, Amanda Wolff ... 9 FICTION ... 11 OVER CANADIAN WHISKEY, Austin Gilmour ... 11 WORDS OF RIGHT, Kira Boswell ... 24 NAPA VALLEY, Cecilia Ehlenbach ... 32 CREATIVE NON‐FICTION ... 38 THE PROFESSIONAL AND THE POLAR TWIN: A FIVE‐ACT DRAMA (WITH AUTHOR’S NOTES), Mark Brennan Kelley ... 3

L’expérimentation animale reste indispensable (OPINION)

Trop fréquemment, l’expérimentation animale est présentée comme une pratique archaïque. Elle a bien changé. Et 100 % des patients traités le sont grâce aux concepts et techniques développés grâce à elle