Interestingly, the gene expression of all CCT subunits in D. antiqua was synchronously increased in association with the increase in cold hardiness (Fig. 2).
The mRNA levels of every CCT subunit in the three tissues of cold-acclimated and winter-diapause pupae increased in accordance with the increase in cold hardiness (Fig. 1, Fig. 2).
In the cold-hardy pupae, the increased levels of CCT protein maintain the higher structure of actin through the suppression of depolymerization or rearrangement of actin monomers, which results in the maintenance of cell membranes and thereby the increase in cold hardiness (Fig. 5B).
This development is irreversible and, once begun, the tissues can no longer increase their hardiness in response to low temperatures (Saxe et al. 2001; Rapacz 2002).
Breeding for increased cold hardiness in plants is an effective method to reduce the loss caused by cold stress.
A 2003 study from the Ohio State University, in which wild sunflowers were experimentally cross-pollinated with genetically modified Bt sunflowers, suggests that modified genes in cultivated crops may drift into closely related populations and increase the hardiness of these plants, including potential weed species.
In recent years, the European varieties have been bred with native American filberts (C. americana in the East and C. cornuta in the West) in an effort to increase hardiness and disease resistance.
And Rachel's three daughters, the delightful Trio, are clearly being given a similar education in hardiness and adventure.
Here, those high in hardiness report significantly fewer PTSD symptoms than those low in hardiness (PTSD symptoms measured by the Impact of Events Scale;[28]).
Under low-stress conditions, those high in hardiness are fairly similar to those low in hardiness in terms of health, in this case PTSD symptoms.
