Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Genes, Developmental”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources

Developmental gene expression in Eimeria bovis.

By differential screening of stage-specific cDNA libraries of Eimeria bovis, we have identified and isolated a large set of genes that are regulated during development of the sporozoites and merozoites. Duplicate lifts of cDNA libraries constructed from partially sporulated oocysts and merozoites were probed with radioactively labeled first-strand cDNA prepared from partially sporulated oocyst and merozoite mRNA. Out of 60,000 plaques screened in each case, over 250 plaques from the partially sporulated oocyst library preferentially hybridized with the oocyst cDNA probe and 67 plaques from the merozoite library preferentially hybridized with the merozoite cDNA probe. Three of the oocyst phage and 7 of the merozoite phage were selected for further characterization. Northern analysis revealed a common pattern of mRNA expression for the oocyst cDNA clones. Consistent with the results of the differential screen, no hybridization to merozoite RNA was detected with any of these 3 oocyst cDNA clones. The expression of the merozoite cDNA clones was more complex, with 3 different classes of merozoite genes being identified based on their pattern of developmental regulation. Although each of the merozoite clones was expressed to some extent during sporulation, in all cases, expression was higher in merozoites than in partially sporulated oocysts, consistent with the restriction of expression defined by the differential screen. Sequence analysis revealed that 2 of the merozoite cDNA clones encode elongation factor 1 alpha and the ubiquitin/ribosomal protein fusion, and 1 of the sporozoite cDNAs displays a significant identity to insulin-degrading enzyme. The developmental expression of E. bovis genes involved in protein synthesis and degradation provides additional evidence for the importance of regulation of protein metabolism during parasite development.

Amino Acid Sequence↗

Tagging developmental genes in Dictyostelium by restriction enzyme-mediated integration of plasmid DNA.

Introduction of restriction enzyme along with linearized plasmid results in integration of plasmid DNA at genomic restriction sites in a high proportion of the resulting transformants. We have found that electroporating BamHI or EcoRI together with pyr5-6 plasmids cut with the same enzyme stimulates the efficiency of transformation in Dictyostelium discoideum more than 20-fold over the rate seen when plasmid DNA alone is introduced. Restriction enzyme-mediated integration generates insertions into genomic restriction sites in an apparently random manner, some of which cause mutations. About 1 in 400 of the Dictyostelium transformants displayed arrested or aberrant development. The integrated plasmid, along with flanking genomic DNA, was excised from some of these mutants, cloned in Escherichia coli, and used to transform other Dictyostelium cells. Homologous recombination within the flanking sequences resulted in the same phenotypes displayed by the original mutants, directly demonstrating that the affected genes were responsible for the specific morphological phenotypes. This method of insertional mutagenesis should be useful for tagging, and subsequent cloning, of many developmentally important genes that can be identified by their mutant phenotypes.

Animals↗

Expression of developmental genes during early embryogenesis of Hydra.

Hydra is a classical model to study key features of embryogenesis such as axial patterning and stem cell differentiation. In contrast to other organisms where these mechanisms are active only during embryonic development, in Hydra they can be studied in adults. The underlying assumption is that the machinery governing adult patterning mimics regulatory mechanisms which are also active during early embryogenesis. Whether, however, Hydra embryogenesis is governed by the same mechanisms which are controlling adult patterning, remains to be shown. In this paper, in precisely staged Hydra embryos, we examined the expression pattern of 15 regulatory genes shown previously to play a role in adult patterning and cell differentiation. RT-PCR revealed that most of the genes examined were expressed in rather late embryonic stages. In situ hybridization, nuclear run-on experiments, and staining of nucleolar organizer region-associated proteins indicated that genes expressed in early embryos are transcribed in the engulfed "nurse cells" (endocytes). This is the first direct evidence that endocytes in Hydra not only provide nutrients to the developing oocyte but also produce maternal factors critical for embryogenesis. Our findings are an initial step towards understanding the molecular machinery controlling embryogenesis of a key group of basal metazoans and raise the possibility that in Hydra there are differences in the mechanisms controlling embryogenesis and adult patterning.

Animals↗

Binary expression of olfactory bulb-protein tyrosine phosphatase in rat central nervous system: developmental gene regulation in neonate cerebral cortex and constitutive expression in olfactory-rhinencephalon.

Olfactory bulb-protein tyrosine phosphatase (OB-PTP) is a receptor type PTPase dominantly expressed in olfactory bulb. Previously, we isolated and molecularly cloned a rat OB-PTP cDNA from an embryonal brain cDNA library. In the present study, we investigated its temporal and spatial gene expression by Northern blot and in situ hybridization analysis. The expression of OB-PTP gene was firstly detected in day 16 post coitum embryo and significantly increased during the late-gestational stage, attaining the highest level in the first week of neonate. The OB-PTP transcript was then down-regulated postnatally and was detected barely in an adult brain. In situ hybridization analysis showed that the transcript was characteristically localized in the postmitotic neurons of cerebral cortex and subcortical structures, and was down-regulated by day 28 when the cortical and subcortical structures have been organized. In the olfactory-rhinencephalon system including olfactory bulb and piriform cortex, the OB-PTP was preferentially expressed in the postmitotic neurons, and in contrast continuously expressed in the matured brain. Based on the evidence that DPTP10D, the Drosophila homolog of OB-PTP, is localized in the axons of specific pioneer neurons in Drosophila embryo, the OB-PTP is presumably involved in the axonogenesis of cortical and subcortical neurons as well as olfactory neurons in mammalian central nervous system. The biological significance of transcriptional regulation in olfactory system is discussed in terms of continuous axonal connections by regenerating olfactory neurons.

Animals↗

Neonatal arthrogryposis and absent limb muscles: a muscle developmental gene defect?

We describe a child who presented at birth with arthrogryposis. Following a muscle biopsy a diagnosis of congenital muscular dystrophy was made and a skin biopsy 12 years later confirmed the presence of merosin. Her clinical picture was unusual, however, for merosin-positive congenital muscular dystrophy. She had extreme wasting and weakness of her arms and legs. In contrast, she had good neck and trunk control, and no facial or respiratory muscle weakness. We have used magnetic resonance imaging to examine the pattern of muscle involvement in this case. No recognizable muscle could be identified in the limbs. In contrast, the axial muscles were preserved. This striking pattern of virtual absence of muscles in the limbs with sparing of the axial muscle suggests that a gene responsible for the migration and/or proliferation of limb muscle precursor cells may be involved in the disease process. It is recognized that merosin-positive congenital muscular dystrophy is a heterogeneous disease. Magnetic resonance imaging is a useful tool for examining in detail the pattern of muscle involvement and identifying individual phenotypes. Understanding more about which muscles are affected in children with congenital myopathies may provide information on the underlying pathological process and help in the search for candidate proteins and genes.

Arthrogryposis↗

A molecular study of abdominal-A in the ant Myrmica rubra reveals lineage dependent evolutionary rates for a developmental gene.

We have characterized the abdominal-A locus in a Hymenopteran, the ant Myrmica rubra. The sequence of the homeotic domain of the Abdominal-A family of orthologous genes is known for a fairly large number of insects but the complete sequence of the Abdominal-A protein, is known only for a few. The two proteins of Drosophila melanogaster and Tribolium castaneum differ markedly outside the homeodomain. A comparison of the ant Abdominal-A protein sequences with those of these two insects shows that the ant and beetle sequences are very similar all along the length of the protein. The fruit fly has diverged considerably and equally from the other two insects. This divergence reflects different rates of evolution of the protein in different lineages.

Amino Acid Sequence↗

The SapB morphogen is a lantibiotic-like peptide derived from the product of the developmental gene ramS in Streptomyces coelicolor.

SapB is a morphogenetic peptide that is important for aerial mycelium formation by the filamentous bacterium Streptomyces coelicolor. Production of SapB commences during aerial mycelium formation and depends on most of the genes known to be required for the morphogenesis of aerial hyphae. Furthermore, the application of purified SapB to mutants blocked in morphogenesis restores their capacity to form aerial hyphae. Here, we present evidence that SapB is a lantibiotic-like peptide that is derived by posttranslational modification from the product of a gene (ramS) in the four-gene ram operon, which is under the control of the regulatory gene ramR. We show that the product of another gene in the operon (ramC) contains a region that is similar to enzymes involved in the biosynthesis of lantibiotics, suggesting that it might be involved in the posttranslational processing of RamS. We conclude that SapB is derived from RamS through proteolytic cleavage and the introduction of four dehydroalanine residues and two lanthionine bridges. We provide an example of a morphogenetic role for an antibiotic-like molecule.

Amino Acid Sequence↗

Expression and function of the developmental gene Wnt-4 during experimental acute renal failure in rats.

The Wnt-beta-catenin pathway plays key roles in embryogenesis. Wnt-4 is known to be expressed in the mesonephric duct in embryonic development. It is tempting to speculate that the Wnt-4-beta-catenin pathway contributes to the recovery from acute renal failure (ARF). This study used an in vivo model of ARF rats to clarify the significance of the Wnt-4-beta-catenin pathway in ARF. ARF was induced by clamping the rat left renal artery for 1 h. At 3, 6, 12, 24, 48, and 72 h after reperfusion, whole kidney homogenate and total RNA were extracted for examination by Western blot analysis and real-time RT-PCR. Wnt-4 mRNA and protein expression were strongly increased at 3 to 12 h and 6 to 24 h after ischemia, respectively. In immunohistologic examination, Wnt-4 was expressed in the proximal tubules and co-expressed with aquaporin-1, GM130, and PCNA. Cyclin D1 and cyclin A were expressed at 24 to 48 h after reperfusion. In addition, the overexpression of Wnt-4 and beta-catenin promoted the cell cycle and increased the promoter activity and protein expression of cyclin D1 in LLC-PK1 cells. Taken together, these data suggest that the Wnt-4-beta-catenin pathway plays a key role in the cell cycle progression of renal tubules in ARF. The Wnt-4-beta-catenin pathway may regulate the transcription of cyclin D1 and control the regeneration of renal tubules in ARF.

Acute Kidney Injury↗

Dynamic changes in developmental gene expression in the basal chordate Ciona intestinalis.

Large-scale expressed sequence tags (EST) analysis was used to demonstrate a number of dynamic changes in the global gene expression profile of the basal chordate Ciona intestinalis over the course of its development. The fertilized egg was found to store a great variety of maternal transcripts and, as development proceeds, the organism expresses a progressively smaller repertoire of genes. In addition, a significant portion of genes involved in embryogenesis were observed to be downregulated during metamorphosis, at which point the adult appears to utilize a different set of genes to form its body. At least 25% of the genes involved in development were found to be used multiple times. This kind of information is essential to form a comprehensive understanding of the overarching expression-control plan by which the basic chordate body is formed.

Age Factors↗

Developmental gene expression in Bacillus subtilis crsA47 mutants reveals glucose-activated control of the gene for the minor sigma factor sigma(H).

The presence of excess glucose in growth media prevents normal sporulation of Bacillus subtilis. The crsA47 mutation, located in the gene for the vegetative phase sigma factor (sigma(A)) results in a glucose-resistant sporulation phenotype. As part of a study of the mechanisms whereby the mutation in sigma(A) overcomes glucose repression of sporulation, we examined the expression of genes involved in sporulation initiation in the crsA47 background. The crsA47 mutation had a significant impact on a variety of genes. Changes to stage II gene expression could be linked to alterations in the expression of the sinI and sinR genes. In addition, there was a dramatic increase in the expression of genes dependent on the minor sigma factor sigma(H). This latter change was paralleled by the pattern of spo0H gene transcription in cells with the crsA47 mutation. In vitro analysis of RNA polymerase containing sigma(A47) indicated that it did not have unusually high affinity for the spo0H gene promoter. The in vivo pattern of spo0H expression is not predicted by the known regulatory constraints on spo0H and suggests novel regulation mechanisms that are revealed in the crsA47 background.

Bacillus subtilis↗

act operon control of developmental gene expression in Myxococcus xanthus.

Cell-bound C-signal guides the building of a fruiting body and triggers the differentiation of myxospores. Earlier work has shown that transcription of the csgA gene, which encodes the C-signal, is directed by four genes of the act operon. To see how expression of the genes encoding components of the aggregation and sporulation processes depends on C-signaling, mutants with loss-of-function mutations in each of the act genes were investigated. These mutations were found to have no effect on genes that are normally expressed up to 3 h into development and are C-signal independent. Neither the time of first expression nor the rate of expression increase was changed in actA, actB, actC, or actD mutant strains. Also, there was no effect on A-signal production, which normally starts before 3 h. By contrast, the null act mutants have striking defects in C-signal production. These mutations changed the expression of four gene reporters that are related to aggregation and sporulation and are expressed at 6 h or later in development. The actA and actB null mutations substantially decreased the expression of all these reporters. The other act null mutations caused either premature expression to wild-type levels (actC) or delayed expression (actD), which ultimately rose to wild-type levels. The pattern of effects on these reporters shows how the C-signal differentially regulates the steps that together build a fruiting body and differentiate spores within it.

Bacterial Proteins↗

Effects of maternal vitamin A status on fetal heart and lung: changes in expression of key developmental genes.

Vitamin A is required during pregnancy for fetal lung development. These experiments monitored fetal lung morphology in normal and vitamin A-deficient rats. The expression of elastin and the growth arrest-specific gene 6 (gas6) in fetal and neonatal hearts and lungs was assessed by Northern blotting. In normal-fed rats, elastin and gas6 were expressed in the fetal lung and heart from day 19 of gestation up to day 2 postnatally. Maternal vitamin A deficiency altered fetal lung development. On day 20, the bronchial passageways were less developed and showed reduced staining for elastic fibers, and in the neonates, the relative air space and the size of the sacculi were reduced. In the fetal lung, the mRNAs for elastin and gas6 were reduced to 56 and 68% of the control values, respectively. In the fetal heart, the mRNA for elastin was reduced to 64% of the control value, whereas gas6 was increased twofold. In the neonate, there was no change in elastin expression in the lung or heart, but gas6 expression in the heart was increased twofold. These results suggest that, in the pregnant rat, vitamin A deficiency may retard fetal lung development or influence the differentiation of critical cell lines. The changes in elastin and gas6 expression may be used to identify the cell types affected.

Animals↗

Developmental gene expression and immunohistochemical study of the human endocrine pancreas during fetal life.

The development of human endocrine pancreas has been the subject of many immunohistochemical studies but very little is known at the molecular level. We have determined the patterns of gene expression of glucagon, somatostatin and pancreatic polypeptide during fetal life (16-41 weeks of gestation) using the dot-blot hybridization method. In spite of some dispersion in the mRNA levels, no progressive increase or decrease during this period of fetal life could be found, as previously observed for insulin. In keeping with these molecular data, no increase in immunostaining of the four hormones was observed, but a dispersion of endocrine cells within the exocrine tissue was noticed at 20 weeks of gestation followed by a clear differentiation of the Langerhans islets at 31 weeks. Interestingly, the mRNA levels of the four hormones were always higher in the fetal pancreas than in the adult pancreas.

Blotting, Northern↗

Developmental gene expression profiling of mammalian, fetal orofacial tissue.

BACKGROUND: The embryonic orofacial region is an excellent developmental paradigm that has revealed the centrality of numerous genes encoding proteins with diverse and important biological functions in embryonic growth and morphogenesis. DNA microarray technology presents an efficient means of acquiring novel and valuable information regarding the expression, regulation, and function of a panoply of genes involved in mammalian orofacial development. METHODS: To identify differentially expressed genes during mammalian orofacial ontogenesis, the transcript profiles of GD-12, GD-13, and GD-14 murine orofacial tissue were compared utilizing GeneChip arrays from Affymetrix. Changes in gene expression were verified by TaqMan quantitative real-time PCR. Cluster analysis of the microarray data was done with the GeneCluster 2.0 Data Mining Tool and the GeneSpring software. RESULTS: Expression of >50% of the approximately 12,000 genes and expressed sequence tags examined in this study was detected in GD-12, GD-13, and GD-14 murine orofacial tissues and the expression of several hundred genes was up- and downregulated in the developing orofacial tissue from GD-12 to GD-13, as well as from GD-13 to GD-14. Such differential gene expression represents changes in the expression of genes encoding growth factors and signaling molecules; transcription factors; and proteins involved in epithelial-mesenchymal interactions, extracellular matrix synthesis, cell adhesion, proliferation, differentiation, and apoptosis. Following cluster analysis of the microarray data, eight distinct patterns of gene expression during murine orofacial ontogenesis were selected for graphic presentation of gene expression patterns. CONCLUSIONS: This gene expression profiling study identifies a number of potentially unique developmental participants and serves as a valuable aid in deciphering the complex molecular mechanisms crucial for mammalian orofacial development.

Animals↗

Myxococcus xanthus encodes an ATP-dependent protease which is required for developmental gene transcription and intercellular signaling.

The bsgA gene of Myxococcus xanthus plays an essential role in the regulation of early gene expression during fruiting body formation and sporulation. bsgA mutants behave as though unable to initiate a required cell-cell interaction and consequently fail to transcribe normal levels of many developmentally induced genes. We determined the nucleotide sequence of bsgA, which predicts a single gene encoding a 90.4-kDa protein. The deduced BsgA protein shares 45 and 48% amino acid identity with the lon genes of Escherichia coli and Bacillus brevis, respectively. The cloned bsgA gene was expressed in E. coli, and the BsgA protein was partially purified and found, like its E. coli homolog, to be an ATP-dependent protease. Thus, the basis for the phenotype of bsgA mutants is likely to be a defect in intracellular proteolysis.

ATP-Dependent Proteases↗

Molecular cloning and characterization of SRG-L, a novel mouse gene developmentally expressed in spermatogenic cells.

Full-length cDNA of a novel mouse gene upregulated in late stages of spermatogenic cells was cloned from mouse testis using overlapping RT-PCR and RACE. The mRNA of the gene was expressed mainly in diplotene/pachytene spermatocytes, round and elongating spermatids. We named this gene as SRG-L (Spermatogenesis Related Gene expressed in late stages of spermatogenic cells, GenBank Accession No. AY352586). The tissue-specific analysis showed a higher expression level in testis and spleen. The gene is mapped on chromosome 8q33.1 and contains 18 exons. The full-length of cDNA is 2,843 bp with an open reading frame (ORF) of 2,625 bp that encodes a 104 kDa protein (874 amino acids) with a putative transmembrane region. The bioinformatics analysis revealed that the SRG-L has two conserved regions, transglutaminase-like homologues domain and D-serine dehydratase domain, rich phosphorylation sites and methylation sites. The SRG-L protein was detected in diplotene/pachytene spermatocytes and spermatids by immunohistochemical staining and Western blot. The results suggest that SRG-L may play definite roles regulating differentiation of germ cells during spermatogenesis, particularly during meiosis and spermiogenesis.

Amino Acid Sequence↗