Effects of heat shock on ovary development and hsp83 expression in Tribolium castaneum (Coleoptera: Tenebrionidae)

Abstract

Heat shock affects reproductive performance in insects including Tribolium castaneum. In this study, the effects of heat shock on ovary development and hsp83 expression in T. castaneum were investigated. Two lines of T. castaneum, H line and C line, from the same base population were established and maintained for five successive generations. In each generation, the newly hatched beetles (within 3 h after eclosion) in the H line were treated with a heat shock at 40 degrees C for 1 h, and those in the C line were raised at normal temperature (30 degrees C) as control treatment. Four traits related to ovary development were measured for the beetles of the fifth generation: days from eclosion to laying the first eggs (T(o)), days from eclosion to laying the first hatchable eggs (T(h)), ovariole size on the third day after eclosion, and pupal mass of their offspring. The results showed that the beetles of the H line had a significantly longer pre-oviposition period (0.6 more days) and smaller ovariole size than those of the C line. No significant difference in pupal mass was observed. Applying heat shock to the offspring of the fifth generation of both lines led to significantly higher hsp83 expression in offspring of the C line than in offspring of the H line. Within each line, the hsp83 expression level in offspring with heat shock was significantly higher than that of offspring without heat shock, but the difference in the C line was much larger than that in the H line. We infer from these results that a tradeoff between heat resistance, registered as hsp83 expression, and ovarian development operates under heat stress in T. castaneum.

An HSP90-regulated reduced-eye phenotype in Tribolium shows fitness benefits and thus provides evidence for evolutionary capacitance

“…Hsp83 knockdown, confirmed by RT-qPCR, resulted in a strong, dose-dependent reduction in the injected males and females, while there were normal Hsp83 levels in their offspring, indicating the depletion of the introduced dsRNA (Figure 1-figure supplement 1A and B). The maternal treatment with the low dsRNA concentration reduced the offspring number, while the high dsRNA concentration completely sterilized the females due to its effects on ovarian maturation and oocyte development, as previously shown (Xu et al, 2010, 2009).…”

Downregulation of the evolutionary capacitor Hsp90 is mediated by social cues

“…We concentrated on the 18 h time point, where Hsp83 expression differences were previously found to be strongest ( figure 1 ), and two treatment groups: N N and N W . In addition to Hsp83 , which codes for the more well-known cytosolic protein of the HSP90 group and is the homologue of Drosophila Hsp83 [ 35 , 53 , 54 ], we included the more recently described paralogue Hsp90 , which codes for an endoplasmatic reticulum-based HSP90 protein [ 34 ]. We predicted that Hsp90 would behave similarly to Hsp83.…”

The function of nuclear receptors in regulation of female reproduction and embryogenesis in the red flour beetle, Tribolium castaneum

“…The following linear models were used for analyzing the expression of each NR, y ij = μ + t i + s j + ts ij + e ijk where y ijl is an observed expression level of each NR, μ is the overall mean, t i is the i th ( i =1,2,3) tissues effect (ovary, fat body or the whole body), s k is the k th ( k =1,2…7) days effect after emergence (from d0 to d7), t sij , is the interaction between tissues and days effect, and e ijk is the residual error, as described previously by Xu et al (2009).…”