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PubMed1985

Immunoassayable adrenocorticotropin in peripheral organs: concentrations during early development.

Although many have identified immunoassayable adrenocorticotropin (ACTH) in sites outside the pituitary (brain, gastrointestinal tract), there is relatively little information regarding immunoassayable ACTH in other major peripheral organs. Several major peripheral organs (pancreas, liver, kidney, heart) of rats were found to contain variable amounts of immunoreactive (IR-) ACTH which appeared to be authentic IR-ACTH on the basis of parallelism to ACTH1-39 upon serial dilution of extracts and gel filtration chromatography. Concentrations of IR-ACTH in peripheral organs were also studied to determine if changes occur during early development. Concentrations of IR-ACTH did not show significant changes in liver and heart at various ages between 10 and 80 days, but IR-ACTH in pancreas and kidney (day 10 vs. 80) did show significant decrements with aging.

Adrenocorticotropic Hormone↗

PubMed2006

Gene families encoding transcription factors expressed in early development of Strongylocentrotus purpuratus.

All genes encoding transcription factors of the bHLH, Nuclear Receptor, Basic Leucine Zipper, T-box, Smad, Sox, and other smaller families were identified in the Strongylocentrotus purpuratus genome by means of a permissive blast search of the genome using a database of known transcription factors. Phylogenetic trees were constructed for the major families, permitting a comparison of the regulatory protein repertoire of the sea urchin and other species. QPCR and whole mount in situ hybridization experiments revealed the temporal and spatial expression patterns of these genes during early development. These regulatory genes are initially expressed at a broad range of time points, and the large majority of genes of all families are expressed within the first 48 h of development. The observations suggest assignment of many regulatory genes to specific developmental sub-networks, including endomesodermal, oral, aboral, and apical.

Animals↗

PubMed1977

Effects of subanesthetic concentrations of enflurane on rat pregnancy and early development.

Anesthetic pollutants in the operating room have been implicated in producing spontaneous abortion in exposed personnel and congenital malformations among their offspring. To test the effects of trace concentrations of enflurane on pregnancy, rats were exposed to two levels (10.7 and 63.7 ppm) of the anesthetic for 8 hr daily from days 1 to 19 of pregnancy. Litter sizes were not affected but birth weights of exposed offspring were slightly higher than controls. During lactation, cross-fostering studies were performed. Exposed offspring were housed with nonexposed mothers and vice versa to determine if exposure during pregnancy affected early development. Weights at 7, 14, and 21 days of age did not differ among the offspring in the lower dose experiment. Weights of the cross-fostered groups in the high dose experiment were decreased at day seven compared to controls. In the same experiment, exposed offspring housed with exposed mothers were heavier than controls on day 21 of lactation. The modest nature of these alterations suggests that enflurane has little or no gross effect on rat pregnancy and postnatal development.

Animals↗

PubMed1991

Changes in cortisol and thyroid hormone concentrations during early development and metamorphosis in the Japanese flounder, Paralichthys olivaceus.

Both cortisol and thyroid hormones were detected in newly fertilized eggs of the Japanese flounder, Paralichthys olivaceus. Mean cortisol levels ranged around 2.5 ng/g wet weight. Cortisol concentrations declined to about one-tenth of their initial levels by 2 days before hatching. The concentrations of triiodothyronine (T3; 7 ng/g) were greater than those of thyroxine (T4; 0.4 ng/g). The T3 levels decreased gradually in the eggs until the time of hatching and then decreased rapidly to undetectable levels within 2 days, whereas T4 remained at more or less constant levels during early development. The significance of the "selective" clearance of the three hormones from eggs remains unclear. Tissue concentrations of cortisol during premetamorphosis were about 4 ng/g and increased to a peak level of 11 ng/g at climax. After climax, cortisol declined by 50%. The changes in thyroid hormone levels were in parallel with the changes in cortisol. T4 remained below 1 ng/g during prematamorphosis but increased gradually during prometamorphosis, reaching peak levels (12 ng/g) during metamorphic climax, and then declined by approximately 50%. T3 remained at low levels through most of the metamorphosis. Histologically, the interrenal tissue was activated during the metamorphosis. The coincident increases in cortisol and thyroid hormones support previous results of a synergistic action of both hormones during metamorphosis in the flounder.

Aging↗

PubMed1995

The concentrations of AcSDKP, a physiological inhibitor of cell proliferation, vary during oogenesis and early development in Xenopus laevis.

The endogenous tetrapeptide AcSer-Asp-Lys-Pro (AcSDKP) is present in the circulation and cells of mammals. Extracellular AcSDKP is a negative regulator of cell proliferation inhibiting the S phase entry of numerous cell types such as hematopoietic progenitors, hepatocytes, lymphocytes and several continuous cell lines. In contrast, the biological role of cellular AcSDKP remains unknown. We have recently reported a decrease of cellular AcSDKP concentrations by 50% accompanying the initiation of DNA synthesis in mitogen-induced proliferation of human lymphocytes. In the present study we measured the variations of cellular AcSDKP concentrations during oogenesis and early development of Xenopus. Cellular AcSDKP concentrations peaked at stage IV of oogenesis and then continuously decreased during the final oocyte maturation and during the initial 15-h period of exponential cell division of the embryo. Altogether, our present and previously published data suggest that cellular AcSDKP may be involved in the regulation of cell proliferation in eukaryotic species.

Amino Acid Sequence↗

PubMed1998

WHSC1, a 90 kb SET domain-containing gene, expressed in early development and homologous to a Drosophila dysmorphy gene maps in the Wolf-Hirschhorn syndrome critical region and is fused to IgH in t(4;14) multiple myeloma.

Wolf-Hirschhorn syndrome (WHS) is a malformation syndrome associated with a hemizygous deletion of the distal short arm of chromosome 4 (4p16.3). The smallest region of overlap between WHS patients, the WHS critical region, has been confined to 165 kb, of which the complete sequence is known. We have identified and studied a 90 kb gene, designated as WHSC1 , mapping to the 165 kb WHS critical region. This 25 exon gene is expressed ubiquitously in early development and undergoes complex alternative splicing and differential polyadenylation. It encodes a 136 kDa protein containing four domains present in other developmental proteins: a PWWP domain, an HMG box, a SET domain also found in the Drosophila dysmorphy gene ash -encoded protein, and a PHD-type zinc finger. It is expressed preferentially in rapidly growing embryonic tissues, in a pattern corresponding to affected organs in WHS patients. The nature of the protein motifs, the expression pattern and its mapping to the critical region led us to propose WHSC1 as a good candidate gene to be responsible for many of the phenotypic features of WHS. Finally, as a serendipitous finding, of the t(4;14) (p16.3;q32.3) translocations recently described in multiple myelomas, at least three breakpoints merge the IgH and WHSC1 genes, potentially causing fusion proteins replacing WHSC1 exons 1-4 by the IgH 5'-VDJ moiety.

Amino Acid Sequence↗

PubMed2004

Analysis of the Tcf-3 promoter during early development of Xenopus.

XTcf-3 functions as a transcriptional regulator in the canonical Wnt signaling cascade and can repress or activate downstream target genes. Expression of XTcf-3 is differentially regulated in time and place during development (Molenaar et al. [1998] Mech Dev. 75:151-154), but little is known about the mechanisms that control transcriptional activation and repression. A 15-kb genomic fragment of Tcf-3 sequences from Xenopus tropicalis was cloned, including the 5' untranslated region; exons 1, 2, and 3; and intron sequences. We used 5' deletion constructs for transgenesis and episomal luciferase assays in Xenopus to examine temporal and spatial regulation of the promoter during early development. A -3054/+34-bp Tcf-3 upstream region was identified that drives a green fluorescent protein (GFP) reporter transgene in a pattern similar to endogenous expression of XtTcf-3 from gastrula to tail bud stages. At stage 12, expression of the reporter is restricted to the middle and posterior neurectoderm. At stage 22, expression is strongest in the neural plate, the eye anlagen and branchial arches. At stage 35/36, expression is found in the head mesenchyme, the branchial arches, the heart, the mesencephalon, eyes, otic vesicles, notochord, somites and the lateral plate mesoderm. Part of the cis-acting elements driving this GFP reporter transgene expression map between -372 and -95 bp of the transcription start site. Furthermore, two TCF/LEF sites are necessary for full activity of the promoter during gastrula stages in episomal luciferase assays.

5' Untranslated Regions↗

PubMed2005

Sea bass (Dicentrarchus labrax) androgen receptor: cDNA cloning, tissue-specific expression, and mRNA levels during early development and sex differentiation.

Androgens play key roles in vertebrate sex differentiation, gonadal maturation and reproductive behaviour and their actions are generally mediated through specific nuclear receptors. The present study describes the isolation, sequencing and characterization of the cDNA encoding the androgen receptor (AR) in the European sea bass. AR was cloned from a sea bass testis cDNA library and encoded a predicted protein of 767 residues, with a calculated molecular weight of 86.4 kDa and a theoretical pI of 6.34. Several domains present in all cloned ARs were identified. The domains corresponded to an amino-terminal hypervariable transcriptional activation domain (TAD), a central highly conserved DNA-binding domain (DBD), and a carboxy-terminal ligand-binding domain (LBD). Percentages of homology-similarity among these functional domains in teleost fish ranged between 9 and 75% for the TAD, 73 and 98% for the DBD, and 78 and 96% for the LBD when compared to those of the sea bass. Tissue-specific expression showed that AR was preferentially expressed in testis, ovaries, and brain. Some other tissues such as the head kidney, liver and spleen also showed AR expression although at very low levels. A semiquantitative PCR was developed to study the expression of AR mRNA during the period of development encompassed between 50 and 300 DPH in sea bass gonads. An experimental design, involving repeated size gradings, based on the fact that sea bass females are larger than males already at sex differentiation, was set to obtain a group consisting of the largest fish (female-dominant) and a group consisting of the smallest fish (male-dominant). The results showed very low mRNA expression levels of AR in the gonads during early development. Differences in AR expression between groups were first encountered at 150 DPH and became especially marked at 250 DPH with much higher levels in the male-dominant group. These sex-related differences in expression profiles between males and females by the time of sex differentiation, suggest an important role for AR controlling this process in the sea bass.

Amino Acid Sequence↗

PubMed1990

Experimental model of type IV Streptococcus agalactiae (group B streptococcus) infection in mice with early development of septic arthritis.

We have established an experimental murine model to gain insight into the pathogenicity and clinical features of type IV group B streptococcus (GBS) infections. Adult CD-1 mice were challenged intravenously with 10(7) type IV GBS cells, inducing systemic invasion. Most of the animals were able to clear the infection from the blood, brain, and lungs within 2 weeks and from the spleen and liver within 1 month. However, the animals were unable to clear the microorganism from the joints and kidneys during the 60-day observation period. About 80% of the mice challenged intravenously with type IV GBS manifested early septic arthritis, which evolved from an acute exudative synovitis to permanent lesions characterized by irreversible joint damage and ankylosis. Induction of persistent septic arthritis was dependent on the number and viability of microorganisms inoculated and was unrelated to the strain of type IV GBS and the growth phase of the inoculum. Type-specific antibodies of both immunoglobulin M and G classes could be detected by agglutination and enzyme-linked immunosorbent assay from days 7 and 14, respectively; immunoglobulin G antibodies persisted for more than 40 days. Complexes of antibodies and group- and type-specific antigens were detected in mouse sera 24 h after infection and persisted up to day 22. These results were obtained an experimental model of type IV GBS chronic infection with early development of septic arthritis, which could be useful in future studies of pathogenicity and immune mechanisms involved in the host resistance to this microorganism.

Animals↗

PubMed2005

The early development of stereotypy and self-injury: a review of research methods.

BACKGROUND: The origin and developmental course of stereotypic and self-injurious behaviour among individuals with developmental disabilities such as intellectual disability (ID) or pervasive development disorders such as autism is not well understood. METHOD: Twelve studies designed to document the prevalence, nature, or development of stereotypic and/or self-injurious behaviour in children under 5 years of age and identified as at risk for developmental delay or disability were reviewed. Comparisons were made with similar studies with typically developing children. RESULTS: It appears that the onset of naturally occurring rhythmic motor stereotypies is delayed in young at-risk children, but that the sequencing may be similar. A very small database, differences in samples, measures, and designs limited the degree to which comparisons could be made across studies. CONCLUSION: Future work is needed based on appropriately designed prospective comparison studies and uniform quantitative measures to provide an empirical basis for new knowledge about the early development of one of the most serious behaviour disorders afflicting children with ID and related problems of development.

Autistic Disorder↗

PubMed1976

Multiple forms of DNA-dependent DNA polymerase during early development and in somatic cells of Xenopus laevis.

Four distinct DNA-dependent DNA polymerase activities (DNA polymerases I, II, III and IV according to the order of elution from a DEAE column) have been separated from extracts of unfertilized Xenopus laevis eggs. The same activities, on the basis of their chromatographic properties, template specificities and sedimentation coefficients, have been found in embryos at least until the gastrula stage. On the other hand, Xenopus kidney cells grown in culture, as well as full grown oocytes lack DNA polymerase I. These data suggest the DNA polymerase I might be a special DNA polymerase activity involved in the extremely rapid DNA synthesis which takes place during early development of X. laevis.

Animals↗

PubMed2005

Profile and analysis of gene expression changes during early development in germinating spores of Ceratopteris richardii.

Analysis of an expressed sequence tag library with more than 5,000 sequences from spores of the fern Ceratopteris richardii reveals that more than 3,900 of them represent distinct genes, and almost 70% of these have significant similarity to Arabidopsis (Arabidopsis thaliana) genes. Eight genes are common between three very different dormant plant systems, Ceratopteris spores, Arabidopsis seeds, and Arabidopsis pollen. We evaluated the pattern of mRNA abundance over the first 48 h of spore development using a microarray of cDNAs representing 3,207 distinct genes of C. richardii and determined the relative levels of RNA abundance for 3,143 of these genes using a Bayesian method of statistical analysis. More than 900 of them (29%) show a significant change between any of the five time points analyzed, and these have been annotated based on their sequence similarity with the Arabidopsis proteome. Novel data arising from these analyses identify genes likely to be critical for the germination and subsequent early development of diverse cells and tissues emerging from dormancy.

Arabidopsis↗

PubMed2000

Changes in the activities of protein phosphatase type 1 and type 2A in sea urchin embryos during early development.

In the eggs and embryos of sea urchins, the activity of protein phosphatase type 2A (PP2A) increased during the developmental period between fertilization and the morula stage, decreased after the prehatching blastula stage and increased again after hatching. The PP2A activity changed keeping pace with alteration to the activities of cAMP-dependent protein kinase (A kinase), Ca2+/calmodulin-dependent protein kinase (CaM kinase) and casein kinase. Probably, PP2A contributes to the quick turning off of cellular signals because of protein phosphorylation. The activity of protein phosphatase type 1 (PP1) was not detectable up to the morula stage and appreciably increased thereafter. In the isolated nucleus fraction, specific activities of PP1 and PP2A were higher than in whole embryos at all stages in early development. Exponential increase in the number of nuclei because of egg cleavage probably makes PP1 activity detectable in whole embryos after the morula stage. In isolated nuclei, the activities of PP1 and PP2A appreciably decreased after hatching, whereas the activities of A kinase, Ca2+/phospholipid-dependent protein kinase (C kinase) and CaM kinase, as well as casein kinase, became higher. In nuclei, cellular signals caused by protein phosphorylation after hatching do not seem to be turned off by these protein kinases so quickly as before hatching. The PP1 and PP2A in nuclei also seem to contribute to the elimination of signal noise.

Animals↗

PubMed1995

Effect of FSH on progesterone secretion by porcine large and small luteal cells isolated from early-developing corpora lutea.

Isolated porcine luteal cells from d 0-3 of the estrous cycle (estrus-d 0) were incubated with or without addition of 0, 10, 10(2) or 10(3) ng FSH/ml. Progesterone (P4) content was determined after 24 hrs of incubation. In nonstimulated conditions the basal P4 production of large cells (LCs) was 65 fold higher than that of small cells (SCs). The LCs but not SCs were stimulated by doses of 10 and 10(2) ng FSH. FSH in doses of 10 and 10(2) ng did not influence P4 production by SCs, but higher doses (10(3) ng) significantly decreased their P4 secretion The results indicated that FSH can have a distinct cellular luteotropic effect during the early development luteal phase of the pig. FSH influenced P4 secretion by LCs whereas, with SCs it had no effect (10 and 10(2) ng) or P4 secretion decreased (10(3) ng).

Animals↗

PubMed2005

Identification of alternative promoter usage for the matrix Gla protein gene. Evidence for differential expression during early development in Xenopus laevis.

Recent cloning of the Xenopus laevis (Xl) matrix Gla protein (MGP) gene indicated the presence of a conserved overall structure for this gene between mammals and amphibians but identified an additional 5'-exon, not detected in mammals, flanked by a functional, calcium-sensitive promoter, 3042 bp distant from the ATG initiation codon. DNA sequence analysis identified a second TATA-like DNA motif located at the 3' end of intron 1 and adjacent to the ATG-containing second exon. This putative proximal promoter was found to direct transcription of the luciferase reporter gene in the X. laevis A6 cell line, a result confirmed by subsequent deletion mutant analysis. RT-PCR analysis of XlMGP gene expression during early development identified a different temporal expression of the two transcripts, strongly suggesting differential promoter activation under the control of either maternally inherited or developmentally induced regulatory factors. Our results provide further evidence of the usefulness of nonmammalian model systems to elucidate the complex regulation of MGP gene transcription and raise the possibility that a similar mechanism of regulation may also exist in mammals.

Animals↗

PubMed1983

Chronic exposure to caffeine during early development increases dendritic spine and branch formation in midbrain optic tectum.

Sibling juvenile jewel fish were chronically exposed to caffeine solution (14 mg/l) between 50 and 100 days after fertilization. Some experimental animals were sacrificed at this time, together with control siblings reared without drugs; others were allowed to recover in the absence of caffeine for 18 months. Golgi-stained preparations showed increased formation of dendritic spines on apical stem dendrites of pyriform tectal neurons in juveniles exposed to caffeine. Adults showed minimal effects on the stem dendrite, but caffeine adults formed more primary dendritic branches and more spines on branches than controls did. This study demonstrates the facilitation of neuronal growth and complexity by chronic administration of a chemical agent commonly present during early development in humans.

Animals↗

PubMed1999

CO2-induced prolongation of expiratory time during early development.

In these studies, we determined the contribution of central mechanisms and the role of GABA(A)-receptor signal transduction pathways in mediating hypercapnia-induced slowing of breathing frequency. Experiments were performed in decerebrate, vagotomized, paralyzed and mechanically ventilated piglets of 3-5 days and 2-3 weeks of age (n=19). Repeated exposure to progressive hyperoxic hypercapnia induced a reproducible increase in phrenic nerve activity, accompanied by a CO2 concentration-dependent increase in expiratory duration. No differences were observed in piglets with intact or cut carotid sinus nerves. Intravenous administration of bicuculline (2 mg/kg: n=7), a gamma-aminobutyric acid (GABA(A)) receptor antagonist, significantly reduced the CO2-induced prolongation of TE. These data demonstrate for the first time that in early postnatal life, hypercapnia induced increase in phrenic activity is associated with centrally mediated prolongation of expiratory duration. Furthermore. the results suggest that brainstem GABAergic mechanisms play an important role in CO2-induced prolongation of expiratory time during early development.

Animals↗

PubMed1995

XCL100, an inducible nuclear MAP kinase phosphatase from Xenopus laevis: its role in MAP kinase inactivation in differentiated cells and its expression during early development.

We have cloned the Xenopus laevis homologue (XCL100) of the human CL100 (Thr/Tyr) MAP kinase phosphatase. Expression of the XCL100 mRNA and protein is inducible by serum stimulation and oxidative/heat stress in a X. laevis kidney cell line. In contrast, XCL100 is constitutively expressed in growing Xenopus oocytes. Recombinant XCL100 protein is able to dephosphorylate both tyrosine and threonine residues of activated p42 MAP kinase in vitro and both the Xenopus and human CL100 proteins were localised predominantly in the nucleus in transfected COS-1 cells. As nuclear translocation of activated MAP kinase is necessary for some of its essential functions in proliferation and cell differentiation our results indicate a role for CL100 in the regulation of these nuclear signalling events. In Xenopus kidney cells both heat shock and serum stimulation lead to transient activation of MAP kinase. However, in contrast to results previously reported from studies on mammalian fibroblasts the inactivation of MAP kinase in these epitheloid cells is rapid and is not dependent on synthesis of new protein. These results indicate that the induction of CL100 (or CL100-like enzymes) may not be required for MAP kinase inactivation in all cell types. Finally, during early embryogenesis, levels of XCL100 mRNA are greatly increased at the mid-blastula transition, suggesting that this enzyme may be involved in the regulation of MAP kinase activity during early development.

Amino Acid Sequence↗