Ontogeny of fetal hepatic and placental growth and in vitro oxygen consumption (VO2) was investigated in fetal lambs at 75, 100, and 136 days postconception. Fetal hepatic relative weight and placental absolute and relative weights declined during this period. Oxygen consumption per gram dry weight of fetal liver and maternal placenta declined between mid and late gestation while fetal placenta...

TCR gene rearrangement is strictly regulated during mouse ontogeny. The V-(D)-J junctions of alphabeta and gammadelta TCR transcripts expressed in the adult thymus are more highly diverse than those in the fetal thymus. We previously showed that adult hematopoietic stem cells (HSC) have a higher capacity to insert N nucleotides into Vgamma4 TCR transcripts than fetal HSC and that the level of N...

Polycomb-group (PcG) proteins are essential regulators of hematopoietic stem cells (HSCs). In contrast to Bmi1, a component of Polycomb repressive complex 1 (PRC1), the role of PRC2 and its components in hematopoiesis remains elusive. Here we show that Ezh2, a core component of PRC2, is essential for fetal, but not adult, HSCs. Ezh2-deficient embryos died of anemia because of insufficient expan...

Bcl11a is a transcription factor known to regulate lymphoid and erythroid development. Recent bioinformatic analysis of global gene expression patterns has suggested a role for Bcl11a in the development of dendritic cell (DC) lineages. We tested this hypothesis by analyzing the development of DC and other lineages in Bcl11a (-/-) mice. We found that Bcl11a was required for expression of IL-7 re...

We recently reported that epidermal growth factor (EGF) levels in the first urine to be voided by intrauterine growth retardation (IUGR) and heavy-for-dates (HFD) infants were lower than control infants (8). In this study, we analyzed EGF receptors to reveal the mechanisms controlling EGF levels. EGF binding to fetal rat liver increased markedly from day 19-21 of gestation. Fetal rats were divi...

Nineteen Landrace sows mated to Landrace boars were randomly assigned, on d 91 of pregnancy, to three groups: (1) control (six sows)--fed standard 13% protein corn-soybean meal gestation diet at 1.82 kg/d to d 112 of pregnancy; (2) 4-d fast (seven sows)--fed standard gestation diet to d 94 of pregnancy, fasted from d 95 to 98 of pregnancy and then refed a semipurified fat-free diet ad libitum u...

We investigated the effect of an isocaloric maternal low-protein diet during pregnancy in rats on the proliferative capacity of cultured fetal hepatocytes. The potential roles of these changes on the IGF-IGF-binding protein (IGFBP) axis, and the role of insulin and glucocorticoids in liver growth retardation, were also evaluated. Pregnant Wistar rats were fed a control (C) diet (20% protein) or...

The ontogeny of the functional capacity of B lymphocytes to generate a heterogeneous response to a haptenic determinant was studied by cell transfer techniques in LAF1 mice. Fetal liver, as a source of B lymphocytes, was transferred into adult, syngeneic, irradiated animals. All recipients received excess adult thymus cells so that T-cell activity did not limit the response and were immunized w...

We recently identified a stage in fetal ontogeny (NK1.1+/CD117+) that defines committed progenitors for T and NK lymphocytes. These cells are found in the fetal thymus as early as day 13 of gestation, but are absent in the fetal liver. Nonetheless, multipotent precursors derived from both the fetal thymus and fetal liver are capable of rapidly differentiating to the NK1.1+ stage upon transfer i...

INTRODUCTION We describe a case of early and persistent reverse end-diastolic flow in the middle cerebral artery in a fetus with severe ascites. These features are associated with a rare liver malformation known as ductal plate malformation. CASE PRESENTATION A 28-year-old Caucasian woman was referred to our high-risk obstetric unit at 24 weeks' gestation for fetal ascites detected during a r...