ABSTRACT The mouse exo utero development system is useful for analyzing the roles of molecules or interactions between tissues in the histogenesis of organs after the mid-gestational period. In the article presented here, we review the mouse exo utero development system and its specific modifications depending on different purposes as well as its advantages over and limitations compared to other systems in the study of developmental biology and teratology.
ABSTRACT We have previously shown that erythropoietin and erythropoietin receptor mRNAs are expressed in mouse embryos and in decidua at the early postimplantation stage, and that erythropoietin receptor mRNA is expressed in advance of erythropoietin mRNA. We subsequently studied the role of exogenous erythropoietin in early development until the embryo proper can express erythropoietin by itself. In the present study, to block the erythropoietin signal in the decidual body where the early postimplantation embryo develops with decidua, we injected an antierythropoietin antibody or soluble erythropoietin receptor into decidual bodies through the uterine wall at day 6 of gestation. For controls, we injected saline or denatured soluble erythropoietin receptor. After 3 or 4 days, we examined the experimental and control decidual bodies. Macroscopic examinations revealed that experimental groups showed anemic small decidua in 50–60% of the decidual bodies of which 18–25% contained developmental-arrested embryos with brain anomalies. Immunohistochemical examination revealed that positive erythropoietin receptor immunoreactivity was detected in the sinusoidal linings of the decidua capsularis and the neuroepithelial cells of the embryos in the controls, while in the experimental groups, these erythropoietin receptor-positive cells were destroyed leading to few erythrocytes in the decidua, and lacy neuroepithelium of the embryos due to apoptosis. In conclusion, erythropoietin from maternal blood appears to be required for sinusoids to retain maternal blood, and for neurogenesis in embryos during a short period of mouse development.
ABSTRACT Hox genes play a critical role in morphogenesis of the early embryo along the anteroposterior axis. In mammals, 39 Hox genes with extensive homology are organized into 13 paralogous groups, forming four clusters on four separate chromosomes. The genes within each cluster are arranged in a 3′ to 5′ direction and expressed in a temporally and spatially coordinated manner along the anteroposterior axis in the vertebrae, limbs and viscera, including the gastrointestinal tract, but little is known about their spatial expression in the adult gastrointestinal tract. We used the quantitative polymerase chain reaction (PCR) intercalater method with SYBR GreenTM to quantify human Hox gene expression in the adult gastrointestinal tract tissue: esophagus, stomach, duodenum, jejunum, ileum, ileocecum, cecum, ascending colon, transverse colon, descending colon and rectum. Hox gene expression was normalized to glyceraldehyde-3-phosphate-dehydrogenase (GAPDH) gene expression. The spatial expression pattern was analyzed by the multivariate method. The expression level of all 39 Hox genes could be measured in a reproducible manner. Genes with higher expression in the foregut-derived segments tended to have lower expression in hindgut-derived segments, whereas those with low expression in the former tended to have higher in the latter. Principal components analysis and permax analysis revealed a position-specific expression pattern of Hox genes along the anteroposterior axis of the adult gastrointestinal tract. The pattern recapitulates the expression pattern in the embryonic gastrointestinal tract. We suggest that Hox genes may play a pivotal role in the position-specific regenerative process of intestinal epithelial cells.
ABSTRACT The phenotype of the genetic polydactyly/arhinencephaly mouse (Pdn/Pdn) is similar to Greig cephalopolysyndactyly syndrome (GCPS), which is induced by mutation of GLI3. Suppression of Gli3 gene expression has been observed in Pdn/Pdn. Thus, the gene responsible for Pdn/Pdn has been considered to be Gli3. Recently, the mutation point was demarcated, that is, a transposon was inserted into intron 3 of the Gli3 gene in the Pdn mouse. Forward and reverse primers were constructed in intron 3 near the insertion point. A forward primer in the long terminal repeat region of the transposon was also constructed. Now we can discriminate +/+, Pdn/+, Pdn/Pdn embryos from the PCR products. After genotyping of the Pdn embryos, Gli3 and other correlated gene expressions, such as sonic hedgehog (Shh), Bmp-2, Bmp-4, ptc-1, were analyzed by real-time PCR method. Gli3 gene expression in Pdn/Pdn was suppressed to 20–30% of +/+, and that in Pdn/+ was about 60% of +/+ through all the embryonic and neonatal periods examined. As Shh has been considered to be an antagonist of Gli3, Shh expression was analyzed, and a difference among genotypes was observed only on day 9 of gestation. We could not detect any alterations among genotypes in other gene expressions examined. Gli3 and Shh gene expression were also analyzed on day 9 by whole-mount in situ hybridization in the +/+ and Pdn/Pdn embryos. Neuroectoderm was positive by Gli3 probe in +/+ but not in Pdn/Pdn. Notochord, floor plate and prechordal mesoderm were positive by Shh probe both in +/+ and Pdn/Pdn embryos, but ectopic and/or over-expression of Shh were not observed in Pdn/Pdn embryos.
ABSTRACT To evaluate the neuronal cytoarchitectural changes in neuronal migration disorders, the immunohistochemical expression of microtubule-associated proteins (MAPs) was analyzed using the experimental model induced by ibotenate in newborn hamsters. The cortical lesions observed after intracerebral ibotenate injections strongly resembled the following neuronal migration disorders: (1) microgyria; (2) focal subcortical heterotopia; (3) focal subependymal heterotopia; and (4) leptomeningeal glioneuronal heterotopia. Microgyria and leptomeningeal glioneuronal heterotopia had MAP2 (HM-2: high and low-molecular-weight forms of MAP2) immunoreactive dendritic processes or neuronal elements. The high molecular weight isoform of MAP2 (AP-20), which is more characteristic of mature neurons, showed enhanced expression in neurons of focal subcortical or subependymal heterotopia, although MAP1B (AA6: early form of MAP) immunoreactive elements were not detected in these heterotopic areas. We conclude that high molecular weight isoform of MAP2 is closely associated with cytoarchitectural repair and remodeling of neuronal processes, resulting in neuronal heterotopia after NMDA receptor activation.
ABSTRACT Miconazole cream is used in Hungary to treat fungal genital and skin infections in pregnant women, but it causes anxiety for both patients and medical doctors due to the category C classification of the drug regarding teratogenic or fetotoxic risk. The objective of this case–control study was to analyze the teratogenic potential of topical miconazole used during pregnancy in the mothers of babies with congenital abnormalities and in matched control mothers of babies without congenital abnormalities. The population-based data set of the Hungarian Case–Control Surveillance of Congenital Abnormalities between 1980 and 1996 included 22 843 women who had newborns or fetuses with congenital abnormalities, and 38 151 pregnant women who had newborn infants without any defects (controls). In the case group, 24 (0.11%) and in the control group, 46 (0.12%) pregnant women were treated with miconazole (crude odd ratio [OR]: 0.9 with 95% confidence interval [CI]: 0.6–1.6). Different congenital abnormality groups were evaluated in case–control pairs and a higher prevalence of miconazole treatment was not found during the second or third month of pregnancy. Thus, treatment with topical miconazole during pregnancy does not increase the risk of congenital abnormalities.
ABSTRACT This study examined immunohistochemically the expression of an enzymatically active form of tyrosine hydroxylase (TH), phosphorylated TH at Ser40 (phospho-TH), in the cerebellum of ataxic mutant mice, rolling mouse Nagoya (RMN) and dilute-lethal (DL). TH immunostaining appeared in some Purkinje cells in RMN and DL, but in a few of the Purkinje cells of littermate controls for both mutants. In all groups of mice, there were no phospho-TH immunoreactive Purkinje cells in the cerebellum, although the subsets of TH immunoreactive Purkinje cells were found in the adjacent sections. The results suggest that TH expression in the Purkinje cells of ataxic mutants abnormally increases without activation of this enzyme by phosphorylation. This may mean that TH in Purkinje cells is not related to catecholamine synthesis.