We have analyzed the genetic basis of these thermal traits using isochromosomal lines for the O chromosome.
The hypothesis we wanted to test in the present study was whether the two neighbouring races, coming from different climate regions, differ in their thermal traits, especially as far as the upper thermal limits and the metabolism are concerned.
This makes ecotherms particularly sensitive to changes in thermal conditions but at the same time provides them with a greater flexibility in thermal traits than their homeotherm counterparts - superficially suggesting that they would be more fitness tolerant to thermal niche shifts [ 23].
The relative extent of phenotypic plasticity of native and introduced populations in thermal traits remains to be explored, however, as this may contribute to the successful establishment of populations in dramatically different climatic areas (e.g., the recent invasion of W. auropunctata in Israel).
For Drosophila, one of the best-studied systems with respect to thermal traits, studies have examined patterns of heat, cold and desiccation resistance across latitude and climate (Parkash and Munjal 1999; Hoffmann et al. 2002; Arthur et al. 2008; Sinclair et al. 2012).
As no data comparing these crucial thermal traits of the two races are available, adequate experiments were conducted with samples from populations of A. m. carnica and A. m. ligustica, obtained from their areas of origin (Styria, Austria and Emilia-Romagna, Italy, respectively), both bred by experts for many generations to assure purity of races.
To clearly juxtapose thermal degradation trait of the a-LAO/STO and c-LAO/STO heterostructures, the sheet conductances of the various heterostructures as a function of annealing temperature are plotted in Fig. 3.
Moreover, previous studies of body size [ 53], life span [ 54, 55] and thermal tolerance traits [ 56] in D. melanogaster indicate that the genetic architecture of each of these traits differs across the sexes.
As temperature can act as a stress inhibitor by affecting several different functions, we used two thermal tolerance traits derived from response fitness curves measured in laboratory experiments: the upper limit of the optimal temperature range (Topt), defined as the range over which feeding occurs and there are no external signs of abnormal behaviour and the optimal spawning temperature (Tsp).
The present study established that coral associated symbionts show heritable variation in thermal tolerance traits.
