Sex-dependent action of prenatal fractionated X-irradiation in the mouse. Biochemical findings

Summary X-Irradiation of pregnant NMRI-mice on gestational days 11–13 with 3×1.05 Gy increased postnatal mortality of the female offspring only. Weights, protein content and acetylcholinesterase, as well as Na, K-ATPase activities in the brains of all treated offspring, were changed. There were, however, no differences between females and males with respect to these parameters.We gratefully acknowledge the assistance of Miss C. Gutmann.     

Cytogenetics of South American akodont rodents (Cricetidae). V. Segregation of chromosome No. 1 polymorphism in Akodon molinae

Akodon molinae is polymorphic with 2n=42, 43, 44, where the metacentric autosome No. 1 is homologous to 2 acrocentrics 1a and 1b. Matings between 2n=43 heterozygotes 1/1a, 1b gave a surplus of 1/1 offspring, a moderate reduction of heterozygous and a strong reduction of homozygous 1a, 1b/1a, 1b offspring. The latter type also has a highly reduced fertility.     

Serum prolactin levels and maintenance of progeny by prenatally-stressed female offspring.

Prenatal stress significantly reduced the number of progeny born to 47% of the female offspring and significantly increased the incidence of low birthweight young. None of these litters survived by the tenth postpartum day when serum prolactin levels were significantly reduced. Upon autopsy, these females had twice as many uterine implantation sites than the number of fetuses they bore, suggesting that a) the reduced postpartum serum prolactin most likely was the cause rather than the effect of the neonatal mortality and b) major hormonal deficiencies (possibly gonadotropic-related) were present even before giving birth.     

Cytogenetics of South American akodont rodents (Cricetidae). V. Segregation of chromosome No. 1 polymorphism inAkodon molinae

Summary Akodon molinae is polymorphic with 2n=42, 43, 44, where the metacentric autosome No. 1 is homologous to 2 acrocentrics 1a and 1b. Matings between 2n=43 heterozygotes 1/1a, 1b gave a surplus of 1/1 offspring, a moderate reduction of heterozygous and a strong reduction of homozygous 1a, 1b/1a, 1b offspring. The latter type also has a highly reduced fertility.This work was supported by grants from the Consejo Nacional de Investigaciones Científicas y Técnicas, the Comisión de Investigaciones Científicas de la Provincia de Buenos Aires and the Organización de Estados Americanos.     

早期营养不良对SD大鼠海马AchE和ChAT表达的影响

目的探讨生命早期营养不良对21天雄性sD大鼠中枢AchE和ChAT的影响。方法从妊娠晚期到哺乳期末给予母鼠半量饲料,造成子鼠营养不良,取哺乳期末雄性子鼠脑海马组织进行测量。结果免疫组化结果示：实验组海马CA3区ChAT光密度低于对照组（P〈0．05）,在CA!区无差异（P〉0．05）;而两纽间CAl和CA3区AchE光密度均无差异（P〉0．05）;RT—PCR示：实验组海马ChAT、AchEmRNA少于对照组（P〈0．05）。结论早期营养不良能导致子鼠海马及中枢胆碱能系统发育障碍,可能会影响成年后大鼠学习记忆能力。     

Androstenedione or corticosterone treatment during pregnancy alters estrous cycle of adult female offspring in mice

Female offspring from mice injected with androstenedione during late pregnancy showed lengthened vaginal cycles, persistent estrus and decreased incidence of pro-estrus and diestrus, whilst offspring from mice injected with corticosterone showed increased incidence of diestrus. These observations give qualified support to the hypothesis that stress during pregnancy alters the female offspring reproductive system through the action of adrenal steroids.     

Androstenedione or corticosterone treatment during pregnancy alters estrous cycle of adult female offspring in mice

Summary Female offspring from mice injected with androstenedione during late pregnancy showed lengthened vaginal cycles, persistent estrus and decreased incidence of pro-estrus and dïestrus, whilst offspring from mice injected with corticosterone showed increased incidence of dïestrus. These observations give qualified support to the hypothesis that stress during pregnancy alters the female offspring reproductive system through the action of adrenal steroids.     

A synergistic interaction between the teratogenic effect of trypan blue and dietary deficiency in the rat.

There was an increased incidence, compared to controls, of exencephaly and microphthalmia in the offspring of rats fed a vitamin D deficient diet and injected with trypan blue on day 9 of gestation. Oral vitamin D did not reverse the effect.     

The effect of continuous exposure to low frequency electric fields on three generations of mice: a pilot study.

Mice were allowed to mate, gestate, deliver and rear their offspring for 3 successive generations while being continuously exposed to 60 Hz electric fields. Mice exposed to vertical electric fields exhibited decreased body weights at 35 days postpartum and increased mortality rates for 3 successive generations. Mice exposed to horizontal electric fields exhibited decreased body weights for 2 successive generations.     

You are what you eat, and so are your children: the impact of micronutrients on the epigenetic programming of offspring

The research field of fetal programming has developed tremendously over the years and increasing knowledge suggests that both maternal and paternal unbalanced diet can have long-lasting effects on the health of offspring. Studies implicate that macronutrients play an important role in fetal programming, although the importance of micronutrients is also becoming increasingly apparent. Folic acid and vitamins B2, B6 and B12 are essential for one-carbon metabolism and are involved in DNA methylation. They can therefore influence the programming of the offspring’s epigenome. Also, other micronutrients such as vitamins A and C, iron, chromium, zinc and flavonoids play a role in fetal programming. Since it is estimated that approximately 78 % of pregnant women in the US take vitamin supplements during pregnancy, more attention should be given to the long-term effects of these supplements on offspring. In this review we address several different studies which illustrate that an unbalanced diet prior and during pregnancy, regarding the intake of micronutrients of both mother and father, can have long-lasting effects on the health of adult offspring.     

Experimental gynogenesis provides evidence of hybridogenetic reproduction in the Rana esculenta complex.

The gynogenetic offspring of the hybrid frog Rana esculenta (R. ridibunda X R. lessonae) are exclusively of the ridibunda type. This is due to the premeiotic exclusion of the lessonae genome from the hybrid's germ cells.     

Critical period for induction of congenital hydrocephalus and dysplasia of subcommissural organ by prenatal X-irradiation in rats

A single whole-body X-irradiation of pregnant Wistar rats at a dose of 1.05 Gy at 10.30, 12.30 and 14.30 h respectively, of gestational day 10 resulted in significantly high incidences of hydrocephalic offspring. No hydrocephalic offspring resulted from X-irradiation of pregnant rats with 1.05 Gy at 16.30 h, whereas a dose of 1.22 Gy at 16.30 h resulted in a low but statistically significant incidence of hydrocephalus. Neither 1.05 Gy nor 1.22 Gy X-irradiation of pregnant rats at 18.30 h resulted in any hydrocephalic offspring. Dysplasia of the subcommissural organ was noticed in all the hydrocephalic brains histologically examined.     

Critical period for induction of congenital hydrocephalus and dysplasia of subcommissural organ by prenatal X-irradiation in rats

Summary A single whole-body X-irradiation of pregnant Wistar rats at a dose of 1.05 Gy at 10.30, 12.30 and 14.30 h respectively, of gestational day 10 resulted in significantly high incidences of hydrocephalic offspring. No hydrocephalic offspring resulted from X-irradiation of pregnant rats with 1.05 Gy at 16.30 h whereas a dose of 1.22 Gy at 16.30 h resulted in a low but statistically significant incidence of hydrocephalus. Neither 1.05 Gy nor 1.22 Gy X-irradiation of pregnant rats at 18.30 h resulted in any hydrocephalic offspring. Dysplasia of the subcommissural organ was noticed in all the hydrocephalic brains histologically examined.     

Queen success is correlated with worker-brood genetic relatedness in a primitively eusocial wasp (Ropalidia marginata)

Ropalidia marginata is a primitively eusocial polistine wasp in which, although there is only one queen at any given time, frequent queen replacements lead to a system of serial polygyny. One of the most striking features of this system, is the enormous variation in the success of different queens. Measuring queen success as queen tenure, total number of offspring produced, number of offspring produced per day of tenure, and proportion of eggs laid that develop into adults, we show here that each measure of queen success is correlated with worker-brood genetic relatedness and not correlated with worker: brood ratio or the age of the queen at takeover. We interpret these results as meaning that queens are better able to obtain the cooperation of workers when worker-brood genetic relatedness is high.     

An antiviral factor from Melia azedarach L. prevents Tacaribe virus encephalitis in mice

Treatment of neonatal mice with an antiviral factor, (AVF), obtained from the leaves of Melia azedarach L. protected them against lethal encephalitis caused by Tacaribe virus inoculation. The degree of protection obtained varied from 66% to 100% depending on the virus dose. Similarly, administration of AVF to nursing mothers protected their offspring from developing virus encephalitis. AVF does not directly inactivate Tacaribe virus; it inhibits an early step (s) in the replication process in cell cultures.     

Francis Galton’s regression towards mediocrity and the stability of types

A prevalent narrative locates the discovery of the statistical phenomenon of regression to the mean in the work of Francis Galton. It is claimed that after 1885, Galton came to explain the fact that offspring deviated less from the mean value of the population than their parents did as a population-level statistical phenomenon and not as the result of the processes of inheritance. Arguing against this claim, we show that Galton did not explain regression towards mediocrity statistically, and did not give up on his ideas regarding an inheritance process that caused offspring to revert to the mean. While the common narrative focuses almost exclusively on Galton’s statistics, our arguments emphasize the anthropological and biological questions that Galton addressed. Galton used regression towards mediocrity to support the claim that some biological types were more stable than others and hence were resistant to evolutionary change. This view had implications concerning both natural selection and eugenics. The statistical explanation attributed to Galton appeared later, during the biometrician-mutationist debate in the early 1900s. It was in the context of this debate and specifically by the biometricians, that the development of the statistical explanation was originally attributed to Galton.     

Persistent inverse maternal effect on corticosterone production in vitro

Adrenal cells from C57BL/Tb mice produced more steroid than those from DBA/2J mice. Reciprocal differences between both backcross and F1 hybrids showed a persistent maternal effect. Mothers with high output produce offspring with reduced hormone production when adult. Corticosterone output thus depends on maternal phenotype as well as on the genotype of the isolated cells.     

Maternal regulation of wing polymorphism inPyrrhocoris apterus: Effect of cold activation

Summary In a macropterous strain ofPyrrhocoris apterus the offspring of females kept under long-day conditions are invariably mostly macropterous, whereas the offspring of females from short-day conditions become macropters under long-day and brachypters under short-day conditions. The brachypterizing effect of short days was removed by the chilling of mothers for 70 days.     

Maternal stress alters monoamine metabolites in fetal and neonatal rat brain

Summary Heat-restraint stress given rats during the last week of gestation significantly altered dopaminergic dihydroxyphenylacetic acid and homovanillic acid (DOPAC and HVA) and noradrenergic 3-methoxy-4-hydroxy-phenyl-ethylene glycol (MOPEG) forebrain-hypothalamic monoamine (MA) metabolites in female offspring. On gestational day 21, HVA and MOPEG were significantly higher and lower, and on postnatal day 1 all were higher. There were virtually no differences in brain MA concentrations in males. Thus MA metabolic concentrations differ in fetal-neonatal forebrain-hypothalamus as a function of sex differences and maternal stress.     

Effects of prenatal stress on the estrous cycle of female offspring as adults

Stress during gestation significantly increased estrous cycle length in female offspring as adults, primarily by lengthening the estrus-metestrus stage. Therefore, prenatal stress may disturb the hormonal milieu of the female fetus during a critical hypothalamic differentiation stage.