Zhao Zhi-Jun Ph.D.: 2003－2006 Supervisors: Prof. Wang De-Hua Present affiliation: Liaocheng University Email: zhaozj73@yahoo.com.cn or zj.zhao@addn.ac.uk Tel: ＋44(0) 1224 274486 (Aberdeen, UK)

Thesis
　　Roles of photoperiod and diet quality in the regulation of energy metabolism, body mass, and thermogenic capacity in Brandt’s voles and Mongolian gerbils

Research interest
　　Small mammal ecological physiology (especially energy metabolism and adaptive regulation in physiology during growth, development, maturation and aging) in response to environmental fluctuations.

Award
　　Scholarship in 2005 and 2006, and awardee of excellent PhD during the course.

Experience as a visiting scholar
　　Colloge of Life Sciences and Medicine, Univesity of Aberdeen (Post-doctoral Reaearch Fellow, 2007.5-2008.5）The Ecology and evolution institute of Russian Academy of Scienses (2006.7)

Doctoral Studies
　　In order to further understand the adaptive physiological strategies in Brandt’s voles (Lasiopodomys brandtii) and Mongolian gerbils (Meriones unguiculatus), based on our previous research and integrated the changes from organism to molecular levels, we determine the body mass, body fat content with ether extraction in a Soxhlet apparatus, energy budgets with metabolism cages, serum levels of iodothyronine (T3), thyroxine (T4) and leptin by radio-immunoassay (RIA), oxygen consumption by a closed-circuit respirometer, cytochrome C oxidase (COX) activity with oxygen electrode units, and uncoupling protein 1 (UCP1) by western blotting in the two species. Our data indicated that Brandt’s voles and Mongolian gerbils exhibited adaptive physiological regulations when exposed to different photoperiods and food qualities. As responses to changes in food quality, voles and gerbils could increase the gut size and food intake, increase the absorbtion by shortening the time of food turnover and reduce energy expenditure by decreasing BMR and/or NST, to compensate for the lower digestibility and higher energy requirement caused by high-fiber diet, and thus maintained a positive energy balance and constant body mass. The plasticity in energy intake, BMR and/or NST was very important for the regulations in energy balance and thermogenesis in Mongolian gerbils exposed to different diets. Change in BAT COX activity and UCP1 was cellular and molecular basis of adaptive thermogeneis. Leptin, an important endocrine factor, was involved in the regulation in energy intake, body mass and thermogenesis in both species. The cause and effect relationship among parameters and the neuroendocrine mechanism for these regulations need further investigation.

Post-doctoral Studies
　　There are several hypothesis about the limits to sustained energy intake, including the hypotheses of central and peripheral limits. However, neither of these hypotheses fully explains the mechanisms that limit sustained energy intake. Król and Speakman (2003) reported a novel hypothesis that the limits to sustained energy intake at peak lactation are imposed by the capacity of the animal to dissipate body heat. In our study, we will manipulate exercise levels of lactating mice by requiring them to run a pre-set distance daily to obtain their food. Once the animal reaches the target number of wheel turns, ad lib food is released from the hopper. We will work with two groups of lactating mice and a control non-exercising group. Food intake, energy expenditure, milk production and pup growth will be measured. This study will provide a valuable test of the novel heat dissipation limit hypothesis. Important

Publications

1. Zhao ZJ, Chi QS, Cao J, Han YD. 2011. The energy budget, thermogenic capacity and behavior in Swiss mice exposed to a consecutive decrease in temperatures. J Exp Biol, (accepted)
2. Zhao ZJ, Liu JJ, Zhang H, Yu R, Zhao YL. 2011. Body mass and behavior in Swiss mice subjected to continuous or discontinuous food restriction and refeeding. Acta Theriol, (accepted)
3. Zhao ZJ, Chi QS. Cao J. 2010. Limits to sustainable energy budget during lactation in striped hamster raising litters of different size. Zoology, (in press)
4. Zhao ZJ, Cao J, Chi QS. 2010. Milk energy output during peak lactation in shaved Swiss mice. Physiol Behav, 101, 59-66.
5. Zhao ZJ, Cao J, Meng XL, Li YB. 2010. Seasonal variations in metabolism and thermoregulation in the striped hamster (Cricetulus barabensis). J Therm Biol,35: 52-57.
6. Zhao ZJ and Wang DH. 2010. Diet-induced obesity in the short-day-lean Brandt's vole. Physiol Behav, 99: 47-53.
7. Zhao ZJ and Cao J. 2009. Effect of fur removal on the thermal conductance and energy budget in lactating Swiss mice. J Exp Biol, 212, 2541-2549.
8. Zhao ZJ and Cao J. 2009. Plasticity in energy budget and behavior in Swiss mice and striped hamsters under stochastic food deprivation and refeeding. Comp Biochem Physiol, 154A, 84-91
9. Zhao ZJ and Wang DH. 2009. Plasticity in the physiological energetics of Mongolian gerbils is associated with diet quality. Physiol Biochem Zool, 82, 504-515.
10. Zhao ZJ, Cao J, Tian Y, Wang RR and Wang GY. 2009. Effects of stochastic food deprivation on energy budget, body mass and activity in Swiss mice. Current Zoology, 55, 249-257.
11. Zhao ZJ and Wang DH. 2007. Effects of diet quality on energy budgets and thermogenesis in Brandt’s voles. Comp Biochem Physiol, 148A,168-177.
12. Zhao ZJ and Wang DH. 2006. Short photoperiod influences energy intake and serum leptin level in Brandt's voles (Microtus brandtii). Horm Behav,49, 463-469.
13. Zhao ZJ and Wang DH. 2006. Effect of photoperiod on body mass, energy balance and thermogenesis in Mongolian gerbils. J Therm Biol, 31,323-331.
14. Zhao ZJ and Wang DH. 2005. Short photoperiod enhances thermogenic capacity in Brandt's voles. Physiol Behav, 85, 143-149.
15. 赵志军．黑线仓鼠繁殖输出与基础代谢率的关系．兽类学报，2010, 30 (4):291 -296.
16. 赵志军．剃毛和增加胎仔数对KM 小鼠哺乳期能量收支的影响．兽类学报，2010, 30(2): 188 -194.
17. 赵志军，曹静，李路胜．小鼠基础代谢率与繁殖输出和繁殖期末器官的关系．动物学杂志，2010, （刊印中）
18. 赵志军，曹静，王桂英，马飞，孟喜龙．随机饥饿和重喂食对小鼠能量代谢和行为的影响．兽类学报，2009, 29(3): 277-285.
19. 赵志军，迟庆生，曹静．小型哺乳动物的持续能量收支限制研究进展．动物学杂志，2009, 44(4): 155-160.
20. 赵志军，王瑞瑞，曹 静，裴兰英．2009．随机限食和重喂食小鼠能量收支和生长发育的可塑性．动物学研究，30(5): 534-538.
21. 赵志军，陈竞峰，王德华．光周期和高脂食物对布氏田鼠能量代谢和产热的影响．动物学报，2008, 54 (4): 576-589.
22. 迟庆生，李兴升，赵志军, 王德华．布氏田鼠胎后发育过程中褐色脂肪组织和肝脏的产热特征．兽类学报，2006, 26(3): 274-279.