Inheritance of protection from osmotic stress

Exposure of mother worms to mild osmotic stress induces gene expression changes in offspring that protect them from strong osmotic stress. Inheritance of protection is now shown to depend on altered insulin-like signalling in the maternal germline, which confers protection through increased expression of zygotic gpdh-2, a rate-limiting enzyme in glycerol biosynthesis

Persistence rate and progression of vertically acquired hepatitis C infection.

Data were collected from 104 infected children who were followed up from birth for a mean of 49 (range, 6-153) months in 22 European centers, to outline the natural history of perinatal hepatitis C virus (HCV) infection. Fifty-four children were persistently HCV RNA positive, 44 were occasionally positive, and 6 never had detectable viremia. At least 90% of the children had evidence of ongoing infection at the latest analysis. Eighteen children became HCV RNA negative at their last assessments, but 40% of these had high alanine aminotransferase (ALT) concentrations. Infection was asymptomatic in all but 2 children, who developed hepatomegaly. Mean ALT concentrations decreased substantially after the first 2 years of life; 14 children had persistently normal ALT values. Signs of minimal to moderate inflammation were noted in all 20 patients who underwent liver biopsy. Perinatal HCV infection is usually asymptomatic in the first years of life, but the virus persists in most children, even in the absence of elevated ALT activity

Transgenerational epigenetic inheritance: how important is it?

Much attention has been given to the idea of transgenerational epigenetic inheritance, but fundamental questions remain regarding how much takes place and the impact that this might have on organisms. We asked five leading researchers in this area--working on a range of model organisms and in human disease--for their views on these topics. Their responses highlight the mixture of excitement and caution that surrounds transgenerational epigenetic inheritance and the wide gulf between species in terms of our knowledge of the mechanisms that may be involved

Ancestral dichlorodiphenyltrichloroethane (DDT) exposure promotes epigenetic transgenerational inheritance of obesity

BACKGROUND: Ancestral environmental exposures to a variety of environmental factors and toxicants have been shown to promote the epigenetic transgenerational inheritance of adult onset disease. The present work examined the potential transgenerational actions of the insecticide dichlorodiphenyltrichloroethane (DDT) on obesity and associated disease. METHODS: Outbred gestating female rats were transiently exposed to a vehicle control or DDT and the F1 generation offspring bred to generate the F2 generation and F2 generation bred to generate the F3 generation. The F1 and F3 generation control and DDT lineage rats were aged and various pathologies investigated. The F3 generation male sperm were collected to investigate methylation between the control and DDT lineage male sperm. RESULTS: The F1 generation offspring (directly exposed as a fetus) derived from the F0 generation exposed gestating female rats were not found to develop obesity. The F1 generation DDT lineage animals did develop kidney disease, prostate disease, ovary disease and tumor development as adults. Interestingly, the F3 generation (great grand-offspring) had over 50% of males and females develop obesity. Several transgenerational diseases previously shown to be associated with metabolic syndrome and obesity were observed in the testis, ovary and kidney. The transgenerational transmission of disease was through both female (egg) and male (sperm) germlines. F3 generation sperm epimutations, differential DNA methylation regions (DMR), induced by DDT were identified. A number of the genes associated with the DMR have previously been shown to be associated with obesity. CONCLUSIONS: Observations indicate ancestral exposure to DDT can promote obesity and associated disease transgenerationally. The etiology of disease such as obesity may be in part due to environmentally induced epigenetic transgenerational inheritance