RESUMEN
We used a genetic system of the gene complex leg-arista-wing complex/TBP related factor 2 (lawc/Trf2) as a suitable model for in vivo study of operational characteristics of divergent overlapping genes. We established lines of transgenic fruit flies carrying constructs capable of expressing hairpin RNA directed at post-transcriptional suppression of the mRNA gene lawc by way of RNA-interference. The attempt to artificially suppress lawc-transcripts caused a rise in the level of expression of the gene lawc by several times. It is shown that change in the concentration of lawc-transcripts can affect the concentration of Trf2 transcripts. Possible mechanisms of regulation of expression of the overlapping genes studied are discussed.
Asunto(s)
Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Genes Sobrepuestos , Proteína 2 de Unión a Repeticiones Teloméricas/genética , Animales , Animales Modificados Genéticamente , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/embriología , Regulación del Desarrollo de la Expresión Génica , Interferencia de ARN , ARN Interferente Pequeño , Proteína 2 de Unión a Repeticiones Teloméricas/metabolismoRESUMEN
A family of closely related genes, named the d4 family, has been previously identified in mammals. It comprises three genes encoding structurally related proteins. The hallmark of the family is d4 domain--a double-paired finger motifthat consists of two tandemly arranged PHD finger domains. These genes are expressed in various tissues and at various developmental stages. Two of those, neuro-d4 and cer-d4, are strictly neurospecific and their expression is developmentally regulated. Another gene, ubi-d4/Requiem is ubiquitously expressed in all embryonic and adult tissues at the same levels. d4 family genes are evolutionary conserved. Human, mouse, rat, and chicken d4 genes have been cloned. The only d4-like gene was found in the genome of nematode C. elegans. The sole member of d4 family was identified also in the genome of D. melanogaster. However, d4 genes are not believed to be present in the genomes of prokaryotes and yeast. This review describes genomic organization and expression ofd4family genes in different organisms.
Asunto(s)
Expresión Génica , Familia de Multigenes , Vertebrados/genética , Secuencias de Aminoácidos , Animales , Caenorhabditis elegans/genética , Pollos/genética , Proteínas de Unión al ADN/genética , Drosophila melanogaster/genética , Regulación del Desarrollo de la Expresión Génica , Humanos , Ratones , Proteínas del Tejido Nervioso/genética , Ratas , Factores de Transcripción/genética , Dedos de Zinc/genéticaAsunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/deficiencia , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Proteínas de Unión al ADN/deficiencia , Proteínas de Unión al ADN/genética , Ingeniería Genética/métodos , Familia de Multigenes/genética , Mutación/genética , Proteínas del Tejido Nervioso/deficiencia , Proteínas del Tejido Nervioso/genética , Factores de Transcripción/deficiencia , Factores de Transcripción/genética , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/clasificación , Proteínas de Unión al ADN/clasificación , Genoma/genética , Ratones , Ratones Noqueados , Proteínas del Tejido Nervioso/clasificación , Factores de Transcripción/clasificaciónRESUMEN
A newly found locus of the Drosophila melanogaster genome, named toothrin (tth) has been used to study the role of the conserved domain 2/3 of genes from the d4 family. In contrast to the 2/3 domain of all vertebrates studied (including humans), which is always accompanied by the d4 domain, the tth gene contains the sequence encoding the 2/3 domain but lacks that encoding the d4 domain. The tth gene overexpression has been studied using the two-component system UAS-GAL4. It has been demonstrated that the tth overexpression at the third-instar larval (prepupal) stage decreases survival rate, simultaneously causing a substantial deceleration of development in Drosophila. It is known that the change of developmental stages in Drosophila is controlled by the rates of the expression of ecdysteroid and juvenile hormones (JHs). It is supposed that the overexpression of the tth gene causes either a shift in the ecdysterone-to-JH ratio (through a decreased JH decay rate or a delayed initiation of ecdysone synthesis) or a deceleration of the release of ecdysterones synthesized.
Asunto(s)
Proteínas de Drosophila/biosíntesis , Drosophila melanogaster/metabolismo , Genes de Insecto , Animales , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Drosophila melanogaster/fisiología , Ecdisteroides/biosíntesis , Ecdisteroides/genética , Hormonas Juveniles/biosíntesis , Hormonas Juveniles/genética , Larva , Metamorfosis BiológicaRESUMEN
Transgenic Drosophila stocks were selected. These stocks contained human ngf and bdnf genes under Drosophila heat-shock promoter. The expression of foreign genes during Drosophila development was demonstrated with Northern and whole mount hybridization.
Asunto(s)
Factor Neurotrófico Derivado del Encéfalo/genética , Drosophila melanogaster/embriología , Regulación del Desarrollo de la Expresión Génica , Factores de Crecimiento Nervioso/genética , Animales , Animales Modificados Genéticamente , Factor Neurotrófico Derivado del Encéfalo/biosíntesis , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Embrión no Mamífero , Proteínas de Choque Térmico/genética , Humanos , Técnicas de Sonda Molecular , Factores de Crecimiento Nervioso/biosíntesis , Regiones Promotoras Genéticas , TransgenesRESUMEN
Two members of the d4 family of presumptive transcription modulators, neuro-d4 (Neud4) and ubi-d4/Requiem (Req), have been characterized previously. We cloned and characterized the third member of this gene family, cer-d4 (Cerd4), from chicken and mouse cDNA libraries. The expression patterns of Cerd4 gene in both species are similar and more restricted than expression patterns of other two d4 genes. The main sites of Cerd4 expression are retina and cerebellum, where multiple transcripts could be detected. Two major types of Cerd4 proteins are a full-length isoform possessing all domains characteristic to the d4 family and truncated XZ isoform without C-terminal tandem of PHD fingers. The developmental kinetics of expression of these isoforms is different. The intron/exon structure of human Cerd4 gene is similar to that of neuro-d4 and ubi-d4/Requiem genes, but most introns of Cerd4 gene are much larger than the corresponding introns of the other two genes.
Asunto(s)
Proteínas de Unión al ADN/genética , Factores de Transcripción/genética , Dedos de Zinc/genética , Secuencia de Aminoácidos , Animales , Embrión de Pollo , Pollos , Mapeo Cromosómico , Clonación Molecular , ADN/química , ADN/genética , ADN Complementario/química , ADN Complementario/genética , Exones , Expresión Génica , Regulación del Desarrollo de la Expresión Génica , Genes/genética , Intrones , Ratones , Ratones Endogámicos , Datos de Secuencia Molecular , Alineación de Secuencia , Análisis de Secuencia de ADN , Homología de Secuencia de AminoácidoRESUMEN
A transgenic line of Drosophila melanogaster was selected which carried the following genes: Delta, lacZ (for bacterial galactosidase), and human GDNF (for glial cell line-derived neurotrophic factor). Drosophila neuroectodermal embryonic cells were transplanted with the embryonic neurohomografts into the occipital brain region of an adult rat. Xenografts were found to block scar formation at the graft-host tissue boundary, stimulated homograft development (so that it was twice as large as the control homograft transplanted alone with no xenograft added), and noticeably improved vascularization of the homograft area.
Asunto(s)
Encéfalo/anatomía & histología , Drosophila melanogaster/genética , Neocórtex/trasplante , Factores de Crecimiento Nervioso , Proteínas del Tejido Nervioso/genética , Animales , Encéfalo/cirugía , Trasplante de Células , Drosophila melanogaster/citología , Drosophila melanogaster/embriología , Embrión no Mamífero/citología , Femenino , Trasplante de Tejido Fetal , Técnicas de Transferencia de Gen , Factor Neurotrófico Derivado de la Línea Celular Glial , Humanos , Inmunohistoquímica , Péptidos y Proteínas de Señalización Intracelular , Operón Lac , Proteínas de la Membrana/genética , Neocórtex/embriología , Ratas , Selección Genética , Trasplante HeterólogoRESUMEN
As the first step toward obtaining the null mutation or knock out of the neuro-d4 gene, we isolated phages containing fragments of the gene from a mouse genomic library. The nucleotide sequence of a region of the gene more than 10 kb in size was determined.
Asunto(s)
Genoma , Proteínas del Tejido Nervioso/genética , Factores de Transcripción , Dedos de Zinc , Secuencia de Aminoácidos , Animales , Bacteriófagos/genética , Secuencia de Bases , ADN , Humanos , Ratones , Ratones Noqueados , Datos de Secuencia Molecular , RatasAsunto(s)
Regulación del Desarrollo de la Expresión Génica , Familia de Multigenes , Ganglio del Trigémino/química , Dedos de Zinc/genética , Empalme Alternativo/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Northern Blotting , ADN/química , Sondas de ADN/química , Femenino , Biblioteca de Genes , Marcación de Gen , Masculino , Ratones , Datos de Secuencia Molecular , Mapeo Físico de Cromosoma , ARN/química , Alineación de Secuencia , Análisis de Secuencia de ADN , Homología de Secuencia de AminoácidoRESUMEN
A 12.5-kb DNA fragment containing the entire human neurogranin gene (hng) was isolated from the genomic phage library using the human neurogranin (hNG) cDNA as a probe. The gene consists of four exons and three introns. The first two exons include the nucleotide sequence that encodes the complete 78-amino acid sequence of neurogranin. It is shown that the genome organization of hug is essentially similar to that of the homologous rat neurogranin gene (rng). The hng gene has several potential transcription start sites, and the promoter region is characterized by the absence of the CCAAT and TATA boxes in the proximal region upstream from the transcription start sites. The 5'-flanking region of hng has a domain with multiple AT-rich motifs, which is similar to the region present nearly at the same position in the promoter of rng. It was shown by fluorescence in situ hybridization that hng is located on chromosome 11 in the region 11q23.3-q24.1.
Asunto(s)
Proteínas de Unión a Calmodulina/genética , Cromosomas Humanos Par 11 , Proteínas del Tejido Nervioso/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Sondas de ADN , ADN Complementario/genética , Exones , Genoma Humano , Biblioteca Genómica , Humanos , Hibridación Fluorescente in Situ , Intrones , Datos de Secuencia Molecular , Neurogranina , Regiones Promotoras Genéticas/genética , Ratas , Homología de Secuencia de Aminoácido , Homología de Secuencia de Ácido Nucleico , TATA Box , Transcripción GenéticaRESUMEN
By using the human fetal brain library, a 1.2-kb cDNA coding for human neurogranin, a neurospecific endogenous substrate of protein kinase C, was cloned. The results of the Northern blot analysis of the human brain cortex mRNA show that the human neurogranin mRNA exists as a single transcript. Its gene thereby differs from the rat neurogranin gene (RC3), which was shown to produce two mRNAs of different lengths. cDNAs of the human and rat neurogranins show a 70% homology, whereas the protein sequences only differ in three amino acid residues out of the total of 78. The 3'-untranslated region of the human neurogranin cDNA lacks the purine-rich stretch characteristic of the rat neurogranin cDNA.
Asunto(s)
Proteínas de Unión a Calmodulina/genética , Proteínas del Tejido Nervioso/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Northern Blotting , Encéfalo/metabolismo , Clonación Molecular , ADN Complementario , Humanos , Datos de Secuencia Molecular , Neurogranina , ARN Mensajero/genética , Homología de Secuencia de AminoácidoRESUMEN
Polymerase chain reaction was applied to human genomic DNA using primers corresponding to the rat substance P receptor cDNA. As a result, a fragment of 94 b.p. was isolated identical to the fragment 771-864 of the above-mentioned cDNA, with the exception of the G796----A substitution (Val----Ile in the amino acid sequence). A comparison of the established sequence with the published structures of tachykinin receptors of NK-1, NK-2 and NK-3 types allows its assignment to the substance P receptor (NK-1 tachykinin receptor) gene detected in the human genome.