The onset and progression of type II diabetes is closely related to environmental factors, in particular dietary habit. Moreover, the environmental exposures very early in life can influence the risk for development of type II diabetes later in life. In this study, we investigated pathophysiological changes in the pups of maternal Spontaneously Diabetic Torii (SDT) rats that were fed a high-fat diet (HFD) throughout gestation and lactation. Maternal SDT rats were continued on HFD for 5 weeks, from day 8 of gestation to day 21 after birth, and biological analyses of the pups were performed from 2 to 22 weeks of age. Results of serum lipid levels in pups from dams fed HFD were higher than pups from dams fed a standard diet, and the onset of diabetes was significantly accelerated in pups from dams fed HFD. In pathological analyses, pups from dams fed HFD showed increases in liver weight and vacuolation of hepatic cells at 2 weeks of age. In conclusion, the metabolic disorder of lipids and glucose in SDT rats is closely related to the nutritional condition of dams during the periods of gestation and lactation.

These physiological phenomena were confirmed at the molecular level. Two genes (CS-ACS1G and CS-ACS2) which encode a key enzyme in the ethylene biosynthesis pathway, 1-aminocyclopropane-1-carboxylic acid (ACC) synthase, were identified as being related to sex expression in cucumber plants. The CS-ACS1G gene, which exists in gynoecious cucumber plants but not in monoecious cucumber plants, was closely linked to the F gene (Trebitsh et al., 1997 Monoecious cucumber (Cucumis sativus L.) produces male and female flowers on the same plant, but application of ethylene promotes expression of female flowers. In the early bisexual stage, all flower buds contain primordia for both stamens and pistils and sexual differences are established by the selective arrest of sexual organ primordia. The expression of six cell cycle-related genes [Cs Cyclin A (CsCycA), CsCycB, CsCycD3; 1, CsCycD3; 2, Cs Cyclin-dependent kinase A CsCDKA), and CsCDKB] was analyzed in male and female flower buds to investigate cell cycle activity in sexual organs. CsCycA was expressed specifically in the area containing arrested stamen primordia (ACASP) in female flower buds, but was barely detected in male flower buds. Expression of the other five genes was detected in the ACASP but not in pistils of female flower buds. Expression of all six genes was elevated transiently following the application of 2-chloroethylphosphonic acid (ethephon), an ethylene-releasing agent, to the shoot apices. The correlation of expression of these genes with the formation of female flowers suggests they play a role in the arrest of stamens of female flowers in monoecious cucumber plants.