This study was performed to evaluate the effect of heat stress on the status of physiological responses, blood parameter, serum T3 and cortisol, and heat shock proteins (HSP 27, 70, and 90) of Hanwoo cattle. Six Hanwoo steers (242.8 ± 7.2 kg of BW) were housed in the climate-controlled respiration chambers. The experiment consisted of 7 days (control; 0 day) at thermoneutral (air temperature (Ta) of 15oC and relative humidity (RH) of 60%; temperature-humidity index (THI) = 64), and by 3 and 6 days (treatment groups) at heat stress (Ta of 35oC and RH of 60%; THI = 87). Body temperature of each parts (frank, rump, perineum and foot) and rectal temperature elevated in heat stress groups (3 days and 6 days) than the control group (0 day). Respiration rates increased in 3 days and 6 days (88.5 ± 0.96 bpm and 86.3 ± 0.63 bpm, respectively) from 0 days (39.5 ± 0.65 bpm). Feed intake significantly decreased in heat stress groups (3 days and 6 days, 3.7 ± 0.14 kg and 4.0 ± 0.15 kg, respectively) than the control group (0 day, 5.0 ± 0.00 kg). In addition, final BW significantly decreased in heat stress groups (3 days and 6 days, 211.8 ± 4.75 kg and 215.5 ± 3.50 kg, respectively) than the control group (0 day, 240.0 ± 25.00 kg). However, heat stress has no significant effect on blood parameter, serum T3 and cortisol. Nevertheless, heat stress increased HSPs mRNA expression in liver tissue, and serum concentration of HSPs. Despite Hanwoo cattle may have high adaptive ability to heat stress, our results suggested that heat stress directly effect on body temperature and respiration rate as well as serum and tissue HSPs. Therefore, we are recommended that HSPs could be the most appropriate indicators of Hanwoo cattle response to heat stress.

A novel oxidant fumigation (NOF) is a commercial bleaching and disinfection agent. Recent study indicates its insecticidal activity. However, its exact mode of action to kill insects is not known. This study sets up a hypothesis that reactive oxygen species released from NOF is a main factor to kill insects. Plodia interpunctella is a lepidopteran insect pest infesting various stored grains. Both larvae and adults were susceptive to NOF. To test the hypothesis, we needed to identify antioxidant genes in P. interpunctella. Superoxide dismutase (SOD) and thioredoxin-peroxidase (Trx) were identified from P. interpunctella EST library using ortholog sequences of Bombyx mori. Both SOD and Trx were expressed in larvae of P. interpunctella expecially against oxidative stress induced by bacterial challenge. The bacterial challenge also induced some heat shock protein (HSP) genes. Similarly, different doses of NOF significantly induced both SOD and Trx genes. There results suggest that NOF at sublethal doses releases reactive oxygen species, which may be detoxified by the antioxidant activities of SOD and Trx of P. interpunctella.

Diapause duration of Paratlanticus ussuriensis is prolonged as an egg that enter both initial and final diapause stgaes. Environmental conditions, such as temperature, can modify the duration of initial diapause. Eggs enter initial diapause at 20℃, but continued early embryonic development at 30℃. Final diapause at a fully developed embryonic stage is obligatory regardless of temperature conditions. To determine temperature effects on initial diapause mechanism of P. ussuriensis eggs, we compared weights, DNA and RNA amounts of eggs incubated at either 20℃ or 30℃ for 50 days after oviposition. We identified small heat shock protein (shsp), heat shock protein 90 (hsp90) and three heat shock protein 70 (hsp70a, hap70b, hsp70c) genes of P. ussuriensis and determined those expression levels at different temperature conditions. The levels of shsp, hsp70a, hsp70b and hsp90 was not detectable until 20 days after oviposition at both temperature conditions, but highly increased at 50 and 60 days when incubated at 30℃. In contrast, hsp70c level was rapidly peaked at 20 days after oviposition, which is the time of initial diapause entrance. We analysis of temperature sensitivity of P. ussuriensis eggs. Hsp70a is expressed after the first cold treatment of mature eggs. Hsp70b is highly expressed just before hatching. Both shsp and hsp70c was highly expressed at the heat shock condition into immature egg stage. Our results suggest that high temperature breakdown initial diapause and one hsp gene, such as hsp70c, may be involved into the mechanism of initial diapause of P. ussuriensis eggs.