The Chinese rare minnow (Gobiocypris rarus) as an in vivo model for endocrine disruption in freshwater teleosts: a full life-cycle test with diethylstilbestrol

Chinese rare minnow (Gobiocypris rarus), a freshwater teleost,. was exposed to diethylstilbestrol (DES) at 0.05, 0.5, 1 and 5 mug/L from fertilized eggs for up to mature period under flow-through condition. Several endpoints that related to development, reproductive fitness and transgenerational effects were evaluated. It was found that body length and body weight were significantly reduced and vitellogenin (Via) levels were significantly increased for fish exposed to DES. Histological examination showed that the sex ratios of F-0 fish skewed to female and about 2% of the fish exposed to 0.05 mug/L DES developed testes-ova. The reproductive success, as determined from data on egg production, was reduced in female fish exposed to 0.05, 0.5, 1 and 5 mug/L DES. The lowest-observed-effect concentrations (LOEC) for chances of sex ratios, reproductive success and histology alteration of F-0 are 0.05 mug/L. In the offspring, transgenerational effects on egg hatching rate. egg fertilization and Vtg levels of juvenile individuals were not observed. However. survival of F, generation fry significantly declined. The analysis of sex steroid levels revealed a significant decrease of testosterone (T) in the whole body homogenates (WBH) of male progeny and somewhat elevation of estradiol (E-T) in the WBH of female offspring. These findings indicate that exposure to DES causes a variety of developmental, reproductive and transgenerational effects. (C) 2004 Elsevier B.V. All rights reserved.

The adjustment of children of Australian Vietnam veterans: is there evidence for the transgenerational transmission of the effects of war-related trauma?

Objective: The presence of posttraumatic stress disorder (PTSD) in trauma survivors has been linked with family dysfunction and symptoms in their children, including lower self-esteem, higher disorder rates and symptoms resembling those of the traumatized parent. This study aims to examine the phenomenon of intergenerational transfer of PTSD in an Australian context.

Method: 50 children (aged 16–30) of 50 male Vietnam veterans, subgrouped according to their fathers' PTSD status, were compared with an age-matched group of 33 civilian peers. Participants completed questionnaires with measures of self-esteem, PTSD symptomatology and family functioning.

Results: Contrary to expectations, no significant differences were found between the self-esteem and PTSD symptomatology scores for any offspring groups. Unhealthy family functioning is the area in which the effect of the veteran's PTSD appears to manifest itself, particularly the inability of the family both to experience appropriate emotional responses and to solve problems effectively within and outside the family unit.

Conclusion: Methodological refinements and further focus on the role of wives/mothers in buffering the impact of veterans' PTSD symptomatology on their children are indicated. Further effort to support families of Veterans with PTSD is also indicated.

Effect of obesity on rat reproduction and on the development of their adult offspring

The aim of the present study was to assess the reproductive parameters of obese Wistar rats and to determine the frequency of their obese adult offspring. Neonatal rats were divided into two groups: F-1 generation, induced to obesity by monosodium glutamate (MSG; F(1)MSG, N = 30), and rats given saline (F1CON, N = 13). At 90 days of age all animals were mated, producing the F-2 offspring (F2CON, N = 28; F(2)MSG, N = 15). Reproductive parameters (fertility, pregnancy, and delivery indexes) were evaluated in F-1 rats. F-2 newborns were weighed, and the obesity parameter for F-1 and F-2 generations was determined from months 5 to 7 of life. At month 7, periovarian fat was weighed and no differences were found. Mean newborn weight also did not differ. The F-1 and F(2)MSG groups presented approximately 90% of obese rats since month 5 of life, whereas F-1 and F2CON groups presented only 33%. There was no difference in periovarian weight among groups. Although obesity did not affect reproductive parameters, obese dams (F(1)MSG) were responsible for the appearance of obesity in the subsequent generation. Thus, obesity induced by neonatal MSG administration did not interfere with reproduction, but did provide a viable model for obesity in second-generation adult Wistar rats. This model might contribute to a better understanding of the pathophysiological mechanisms involved in transgenerational obesity.

Transgenerational effects of temperature on egg and larval development in Cyprinodon variegatus

Transgenerational plasticity (TGP), a type of maternal effect, occurs when the environment experienced by one or both the parents prior to fertilization directly translates, without changing DNA sequences, into changes in offspring reaction norms. Evidence of such effects has been found in several traits throughout many phyla, and, although of great potential importance - especially in a time of rapid climate change - TGP in thermal growth physiology had never been demonstrated for vertebrates until the first experiment on thermal TGP in sheepshead minnows, who, given sufficient time, adaptively program their offspring for maximal egg viability and growth at the temperature experienced before fertilization. This study on sheepshead minnows from South Carolina and Connecticut investigates how population, parent temperature, and offspring temperature affect egg production, size, viability, larval survival and growth rates, whether these effects provide evidence of TGP, and whether and how they vary with length of exposure time (5, 12, 19, 26, 33 and 43 days) of the parents to the new experimental temperatures of either 26°C or 32°C. Several results are consistent with those obtained in the previous TGP study, which outline a sequence of events consisting of an initial adjustment period to the new temperatures, in which egg production decreases and no signs of TGP are present, followed by a shift to TGP (towards 26-33 days of exposure) in which parents start to produce more eggs which are better adapted to the new thermal environment. Other results present new information, such as signs of TGP in the parent temperature effect on egg sizes already around 20 days of exposure. The innovative idea of populations being able to adapt to rapidly shifting environments through non-genetic mechanisms such as TGP opens new possibilities of survival of species and will have important implications on ecology, physiology, and contemporary evolution.