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Plant phosphate transporter (PT) genes comprise a large family with important roles in various physiological and biochemical processes. In this study, a database search yielded 26 potential PT family genes in rice (Oryza sativa). Analysis of these genes led to identification of eight conserved motifs and 5-12 trans-membrane segments, most of them conserved. A total of 237 putative cis elements were found in the 2-kb upstream region of these genes. Of these, a majority were Pi-response and other stress-related cis regulatory elements, such as PHO-like, TATA-box-like, PHR1, or Helix-loop-helix elements, and WRKY1 and ABRE elements, suggesting gene regulation by these signals. Comprehensive expression analysis of these genes was performed using data from microarrays hybridized with RNA from 27 tissues covering the entire lifecycle from three rice genotypes: Minghui 63, Zhenshan 97, and Shanyou 63. Real-time PCR analysis confirmed that three rice PT genes are preferentially expressed in stamen at 1 d before flowering, two in panicle at the heading stage, and two in flag leaf at 14 d after the heading stage. Hormone-treatment experiments revealed differential up-regulation or down-regulation of 11 rice PT genes in seedlings exposed to five hormones, respectively. These results will be useful for elucidating the roles of these genes in the growth, development, and stress response of the rice plant.

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The aim of the present study was to determine the potential long-term metabolic effects of early nutritional programming on carbohydrate utilisation in adult zebrafish (Danio rerio). High-carbohydrate diets were fed to fish during four ontogenetic stages: from the firstfeeding stage to the end of the yolk-sac larval stage; from the first-feeding stage to 2 d after yolk-sac exhaustion; after yolk-sac exhaustion for 3 or 5 d. The carbohydrate stimuli significantly increased the body weight of the first-feeding groups in the short term. The expression of genes was differentially regulated by the early dietary intervention. The high-carbohydrate diets resulted in decreased plasma glucose levels in the adult fish. The mRNA levels and enzyme activities of glucokinase, pyruvate kinase, a-amylase and sodium-dependent glucose co-transporter 1 were up-regulated in the first-feeding groups. There was no significant change in the mRNA levels of glucose-6-phosphatase (G6Pase) in any experimental group, and the activity of G6Pase enzyme in the FF-5 (first feeding to 2 d after yolk-sac exhaustion) group was significantly different from that of the other groups. The expression of phosphoenolpyruvate carboxykinase gene in all the groups was significantly decreased. In the examined early programming range, growth performance was not affected. Taken together, data reported herein indicate that the period ranging from the polyculture to the external feeding stage is an important window for potential modification of the long-term physiological functions. In conclusion, the present study demonstrates that it is possible to permanently modify carbohydrate digestion, transport and metabolism of adult zebrafish through early nutritional programming.Key words: First feeding: Early nutritional programming: Carbohydrate diets: Glucose metabolism: ZebrafishThe use of carbohydrates as digestible energy sources in fish diets bears economic significance in aquaculture industry (1) .Diets that contain digestible carbohydrates can promote rapid growth and provide metabolic intermediates for the synthesis of other biologically important compounds (2,3) . When carbohydrates are not provided in feedstuffs, more proteins are catabolised for energy and for the synthesis of glucose, which impairs protein retention and increases N excretion into the environment (1,4) . Therefore, it is important to provide an appropriate amount of carbohydrates in fish diets. However, the mechanisms of carbohydrate digestion, absorption and metabolism are different among different fish species; that is, omnivorous or herbivorous fish can utilise higher amounts of dietary carbohydrates and exhibit a greater degree of protein sparing (5 -7) , whereas carnivorous fish species have a relatively low ability to utilise carbohydrates (8) . The liver plays an important role in the coordination of whole-body metabolic functions in response to nutritional status. Specifically, in conjunction with the gastrointestinal tract, the liver plays a major role in glucose metabol...

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