Maternal loading of a small heat shock protein increases embryo thermal tolerance inDrosophila melanogaster

Abstract

Maternal investment is likely to have direct effects on offspring survival. In oviparous animals whose embryos are exposed to the external environment, maternal provisioning of molecular factors like mRNAs and proteins may help embryos cope with sudden changes in the environment. Here, we sought to modify the maternal mRNA contribution to offspring embryos and test for maternal effects on acute thermal tolerance in early embryos of We drove overexpression of a small heat shock protein gene () in female ovaries and measured the effects of acute thermal stress on offspring embryonic survival and larval development. We report that overexpression of the gene in female ovaries produced offspring embryos with increased thermal tolerance. We also found that brief heat stress in the early embryonic stage (0-1 h old) caused decreased larval performance later in life (5-10 days old), as indexed by pupation height. Maternal overexpression of protected embryos against this heat-induced defect in larval performance. Our data demonstrate that transient products of single genes have large and lasting effects on whole-organism environmental tolerance. Further, our results suggest that maternal effects have a profound impact on offspring survival in the context of thermal variability.

Small heat shock proteins determine synapse number and neuronal activity during development

“…In particular, these two chaperons are associated to temperature changes [48,49], environmental-stress-induced degeneration [50,51] and lifespan [52]. Besides, maternal loading of sHSP23 determines embryonic thermal tolerance pointing to a physiological role during development [53]. All these evidences support that sHsp disruption during embryogenesis and development can be associated to physiological defects in adulthood, therefore Pkm-sHSPs contribution during development is proposed as a central mechanism for nervous system correct formation, function and response to environmental stress.…”

Biogeographic parallels in thermal tolerance and gene expression variation under temperature stress in a widespread bumble bee

“…Our results show some overlap with differentially expressed genes observed in diapausing/post-diapausing B. terrestris queens and some Megachile 66 , 70 , and future research on old stress in queens and links to worker physiology would be particularly informative for understanding true targets of selection for cold tolerance. A related caveat is that while experimental workers were reared in the lab and never experienced field conditions that would alter their physiology via plasticity or acclimation, queens did overwinter in the field, which could contribute to maternal effects relating to region of origin 71 , 72 . Such effects might be avoided by rearing second-generation colonies, but this proved unsuccessful for B. vosnesenskii and is a technical challenge that must be overcome.…”

Developmental Expression and Functions of the Small Heat Shock Proteins in Drosophila

“…Hsp23 and Hsp26 exhibit distinct spatial and temporal patterns of expression [ 24 , 31 ]. Hsp26 mRNA is present in nurse cells and later in the oocyte, and recent studies [ 32 ] reveal that maternal loading of the Hsp23 plays an important role in thermal tolerance: overexpression of Hsp23 in female oocytes significantly increased thermal tolerance in offspring embryos and larval performance [ 32 ]. Marin et al [ 33 ] reported that, in head and testes, Drosophila Hsp23 is constitutively expressed in two forms (native Hsp23a and more acidic Hsp23b ).…”