Gene expression, metabolic regulation and stress tolerance during diapause

Abstract

Diapause entails molecular, physiological and morphological remodeling of living animals, culminating in a dormant state characterized by enhanced stress tolerance. Molecular mechanisms driving diapause resemble those responsible for biochemical processes in proliferating cells and include transcriptional, post-transcriptional and post-translational processes. The results are directed gene expression, differential mRNA and protein accumulation and protein modifications, including those that occur in response to changes in cellular redox potential. Biochemical pathways switch, metabolic products change and energy production is adjusted. Changes to biosynthetic activities result for example in the synthesis of molecular chaperones, late embryogenesis abundant (LEA) proteins and protective coverings, all contributing to stress tolerance. The purpose of this review is to consider regulatory and mechanistic strategies that are potentially key to metabolic control and stress tolerance during diapause, while remembering that organisms undergoing diapause are as diverse as the processes itself. Some of the parameters described have well-established roles in diapause, whereas the evidence for others is cursory.

The African turquoise killifish: A research organism to study vertebrate aging and diapause

“…Diapause is a specialized state characterized not only by a temporal suspension of development but also by an extreme tolerance to various stresses to protect offspring from an adverse environment (MacRae, 2010; Schiesari & O'Connor, 2013). As a consequence, it helps the species survive extreme forms of stress (e.g., drought) and it also “times” the birth of offspring to a more favorable environment (e.g., rainy season).…”

Population dependent effects of photoperiod on diapause related physiological traits in an invasive beetle (Leptinotarsa decemlineata)

“…This decision is usually the integrated response to several environmental cues, such as photoperiod, temperature, food availability and humidity (Danilevski 1965, Tauber et al 1986). Adult diapause is usually characterized by reproductive arrest, suppressed metabolism and high tolerance to many environmental stressors, such as low temperatures, desiccation, and increased risk of infections (Danks 1987, MacRae 2010. Variation in the intensity and mode of diapause is very large (Tauber et al 1986, Saunders 2002, Hahn & Denlinger 2007.…”

“…The mechanism is usually referred to as homeoviscous adaptation. Another typical feature of diapausing insects is the chronic and inducible upregulation of heat shock protein (HSP) expression (Yocum 2001, Denlinger 2002, MacRae 2010. Heat shock proteins are molecular chaperones which assist in regulating the functionality of proteins during times of cellular stress (low/high pH or temperature for instance) (Lindquist 1986, Goto and Kimura 1998, Feder & Hoffmann 1999, Hochachka & Somero 2002.…”

“…Heat shock proteins are molecular chaperones which assist in regulating the functionality of proteins during times of cellular stress (low/high pH or temperature for instance) (Lindquist 1986, Goto and Kimura 1998, Feder & Hoffmann 1999, Hochachka & Somero 2002. During diapause, several different heat shock proteins have been found to be up-regulated for long periods, in some cases the whole overwintering period (Denlinger 2002, Rinehart et al 2007, MacRae 2010. Also other stress related proteins, such as desiccation proteins have been found to be up-regulated during diapause (Graham et al 1996, Yocum 2003, Yocum et al 2011.…”

Seasonal phenotype‐specific transcriptional reprogramming during metamorphosis in the European map butterfly Araschnia levana

“…Caterpillars encountering long‐day (LD) conditions develop rapidly into adult butterflies of the summer generation (Reinhardt 1984). Their offspring are exposed to short‐day (SD) conditions, and the resulting pupae enter a dormant state known as diapause characterized by enhanced stress tolerance, which is necessary to survive winter temperatures and prolonged exposure to pathogens (MacRae 2010). Both the day length during larval development and the temperature during early pupal development are known to influence the imago phenotype (Reinhardt 1984; Koch 1992; Windig and Lammar 1999).…”