In utero Exposure to Anesthetics Alters Neuronal Migration Pattern in Developing Cerebral Cortex and Causes Postnatal Behavioral Deficits in Rats.

During fetal development, cerebral cortical neurons are generated in the proliferative zone along the ventricles and then migrate to their final positions. To examine the impact of in utero exposure to anesthetics on neuronal migration, we injected pregnant rats with bromodeoxyuridine to label fetal neurons generated at embryonic Day (E) 17 and then randomized these rats to 9 different groups receiving 3 different means of anesthesia (oxygen/control, propofol, isoflurane) for 3 exposure durations (20, 50, 120 min). Histological analysis of brains from 54 pups revealed that significant number of neurons in anesthetized animals failed to acquire their correct cortical position and remained dispersed within inappropriate cortical layers and/or adjacent white matter. Behavioral testing of 86 littermates pointed to abnormalities that correspond to the aberrations in the brain areas that are specifically developing during the E17. In the second set of experiments, fetal brains exposed to isoflurane at E16 had diminished expression of the reelin and glutamic acid decarboxylase 67, proteins critical for neuronal migration. Together, these results call for cautious use of anesthetics during the neuronal migration period in pregnancy and more comprehensive investigation of neurodevelopmental consequences for the fetus and possible consequences later in life.

Identification of novel genes regulated by chorionic gonadotropin in baboon endometrium during the window of implantation.

Chorionic gonadotropin (CG) is an early embryo-derived signal that is known to support the corpus luteum. An in vivo baboon model was used to study the direct actions of human CG (hCG) on the endometrium, during the periimplantation period. Endometrial gene expression was analyzed using microarrays. The endometrial biopsies were taken from hCG-treated (n = 5) and control (n = 6) animals on d 10 after ovulation. Class comparison identified 61 genes whose transcript levels differed between control and hCG-treated samples (48 increased, 13 decreased in mean expression level more than 2.5-fold; P < 0.01). Real-time PCR of transcript abundance confirmed up-regulation of several of these, including SerpinA3, matrix metalloproteinase 7, leukemia inhibitory factor (LIF), IL-6, and Complement 3 (P

A novel nuclear protein, 5qNCA (LOC51780) is a candidate for the myeloid leukemia tumor suppressor gene on chromosome 5 band q31.

Interstitial deletion or loss of chromosome 5, del(5q) or -5, is a frequent finding in myeloid leukemias and myelodysplasias, suggesting the presence of a tumor suppressor gene within the deleted region. In our search for this gene, we identified a candidate, 5qNCA (LOC51780), which lies within a consistently-deleted segment of 5q31. 5qNCA expresses a 7.2-kb transcript with a 5286-bp open reading frame which is present at high levels in heart, skeletal muscle, kidney, placenta, and liver as well as CD34+ cells and AML cell lines. 5qNCA encodes a 191-kD nuclear protein which contains a highly-conserved C-terminus containing a zinc finger with the unique spacing Cys-X2-Cys-X7-His-X2-Cys-X2-Cys-X4-Cys-X2-Cys and a jmjC domain, which is often found in proteins that regulate chromatin remodeling. Expression of 5qNCA in a del(5q) cell line results in suppression of clonogenic growth. Preliminary sequence results in AML and MDS samples and cell lines has revealed a possible mutation in the KG-1 cell line resulting in a THR to ALA substitution that has not been found in over 100 normal alleles to date. We propose 5qNCA is a good candidate for the del(5q) tumor suppressor gene based on its predicted function and growth suppressive activities, and suggest that further mutational and functional study of this interesting gene is warranted.

The human gene for the type III isozyme of hexokinase: structure, basal promoter, and evolution.

The structure of the gene for the Type III isozyme of human hexokinase is nearly identical to that of previously characterized genes for other isozymes of hexokinase. The most striking difference is that the 5'-untranslated sequence and the initial coding sequence are contained in two exons in the Type III hexokinase gene but in a single exon in genes for the other isozymes. Sequence at the transcriptional start site for rat Type III hexokinase (S. Sebastian, J. A. White, and J. E. Wilson, 1999, J. Biol. Chem. 274, 31700-31706) is conserved in the human gene, as is an Oct-1 site, in reverse orientation, approximately 30 bp upstream from the start site. This site has been shown to regulate transcription of both human and rat genes for Type III hexokinase. Comparison of the genes for the various mammalian isozymes of hexokinase indicates that a major feature in the evolution of this isozyme family has been acquisition of alternative first exons.

Highly abundant genes in the transcriptosome of human and baboon CD34 antigen-positive bone marrow cells.

Nonhuman primates are useful large animal model systems for the in vivo study of hematopoietic stem cell biology. To better understand the degree of similarity of the hematopoietic systems between humans and baboons, and to explore the relevance of such studies in nonhuman primates to humans, this study was designed to compare the global gene expression profile of bone marrow CD34(+) cells isolated from these 2 species. Human complementary DNA (cDNA) filter arrays containing 25 920 human cDNAs were surveyed for this purpose. The expression pattern and relative gene abundance of the 2 RNA sources were similar, with a correlation coefficient of 0.87. A total of 15 970 of these cDNAs were expressed in human CD34(+) cells, of which the majority (96%) varied less than 3-fold in their relative level of expression between human and baboon. Reverse transcriptase-polymerase chain reaction analysis of selected genes confirmed that expression was comparable between the 2 species. No species-restricted transcripts have been identified, further reinforcing the high degree of similarity between the 2 populations. A subset of 1554 cDNAs, which are expressed at levels 100-fold and greater than background, is described, which includes 959 expressed sequence tags and uncharacterized cDNAs, and 595 named genes, including many that are clearly involved in hematopoiesis. The cDNAs reported here represent a selection of some of the most highly abundant genes in hematopoietic cells and provide a starting point to develop a profile of the transcriptosome of CD34(+) cells.

High-resolution physical map and transcript identification of a prostate cancer deletion interval on 8p22.

A genomic interval of approximately 1-1.5 Mb centered at the MSR marker on 8p22 has emerged as a possible site for a tumor suppressor gene, based on high rates of allele loss and the presence of a homozygous deletion found in metastatic prostate cancer. The objective of this study was to prepare a bacterial contig of this interval, integrate the contig with radiation hybrid (RH) databases, and use these resources to identify transcription units that might represent the candidate tumor suppressor genes. Here we present a complete bacterial contig across the interval, which was assembled using 22 published and 17 newly originated STSs. The physical map provides twofold or greater coverage over much of the interval, including 17 BACs, 15 P1s, 2 cosmids, and 1 PAC clone. The position of the selected markers across the interval in relation to the other markers on the larger chromosomal scale was confirmed by RH mapping using the Stanford G3 RH panel. Transcribed units within the deletion region were identified by exon amplification, searching of the Human Transcript Map, placement of unmapped expressed sequence tags (ESTs) from the Radiation Hybrid Database (RHdb), and from other published sources, resulting in the isolation of six unique expressed sequences. The transcript map of the deletion interval now includes two known genes (MSR and N33) and six novel ESTs.