RESUMO
5-Bromo-2’-deoxyuridine (BrdUrd) has long been known to interfere with cell differentiation. We found that treatment ofBradysia hygida larvae with BrdUrd during DNA puff anlage formation in the polytene chromosomes of the salivary gland S1 region noticeably affects anlage morphology. However, it does not affect subsequent metamorphosis to the adult stage. The chromatin of the chromosomal sites that would normally form DNA puffs remains very compact and DNA puff expansion does not occur with administration of 4 to 8 mM BrdUrd. Injection of BrdUrd at different ages provoked a gradient of compaction of the DNA puff chromatin, leading to the formation of very small to almost normal puffs. By immunodetection, we show that the analogue is preferentially incorporated into the DNA puff anlages. When BrdUrd is injected in a mixture with thymidine, it is not incorporated into the DNA, and normal DNA puffs form. Therefore, incorporation of this analogue into the amplified DNA seems to be the cause of this extreme compaction. Autoradiographic experiments and silver grains counting showed that this treatment decreases the efficiency of RNA synthesis at DNA puff anlages.
Assuntos
Animais , Bromodesoxiuridina/farmacologia , DNA , Dípteros/genética , Proteínas de Insetos/efeitos dos fármacos , Glândulas Salivares/química , Proteínas e Peptídeos Salivares/efeitos dos fármacos , Autorradiografia , Diferenciação Celular , Proteínas de Insetos/genética , Larva/efeitos dos fármacos , Glândulas Salivares/efeitos dos fármacos , Proteínas e Peptídeos Salivares/genéticaRESUMO
BhB10-1 is an amplified gene present in DNA puff B10. This gene is very active in the salivary gland regions S1 and S3 at the end of the larval development. Two transcripts of this gene, 1.3 and 1.1 kb in size, were detected. A secretory protein, SP23, is the product of BhB10-1. In this work, we present evidence supporting the hypothesis that a biphasic process of mRNA degradation is an important component in the control of BhB10-1 gene expression. The 1.3 kb transcript, by a process of poly(A) tail shortening, is converted to the inactive transcript of 1.1 kb which is detected during and after the period of SP23 expression. Cycloheximide in very low concentration, if applied at a proper time, can disrupt this process leading to extended periods of 1.3 kb RNA detection and SP23 synthesis. A tentative model is proposed to explain this phenomenon.
Assuntos
Cicloeximida/farmacologia , Dípteros/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Genes de Insetos , Inibidores da Síntese de Proteínas/farmacologia , Animais , Poliadenilação , RNA , Glândulas Salivares/metabolismoRESUMO
O estudo citogenético convencional em uma menina com aniridia esporádica resultou em uma aparente translocaçäo balanceada t(11;13)(p13;q33) de novo. Entretanto, o estudo citogenético pela hibridaçäo in situ fluorescente (FISH) detectou a presença de uma deleçäo críptica 11p13p14, incluindo a regiäo WAGR e envolvendo aproximadamente 7.5 Mb de DNA, deletando os genes PAX6 e WT1. Estes resultados correlacionam-se com o quadro clínico da paciente e a coloca em alto risco de desenvolver tumor de Wilms. A ausência de retardo mental na paciente indica que a posiçäo distal do ponto de quebra poderá refinar o mapeamento do locus retardo mental na síndrome de genes contíguos WAGR (Wilms, aniridia, anomalias genitais e retardo mental).
Assuntos
Humanos , Feminino , Recém-Nascido , Lactente , Pré-Escolar , Aniridia/genética , Hibridização in Situ Fluorescente , Deleção Cromossômica , Síndrome WAGR/genéticaRESUMO
During the last 30 h of the larval stage, the salivary glands of Bradysia hygida show the amplification of some genes, resulting in the formation of two successive groups of DNA puffs, which direct the synthesis of two different sets of polypeptides. Incubation of anterior (S1) salivary gland regions, at age E7, beginning of first group of DNA puffs activity, in culture medium for 2 to 10 h results in a decrease in the synthesis of the polypeptides characteristic of this period. However, during subsequent incubation (from E7 to E7+12 h-24 h), when the second group of DNA puffs is active, S1 regions were able to synthesize some polypeptides characteristic of this period. The role of 20-OH ecdysone was studied, in vitro and in vivo, during these two periods of protein synthesis in S1 regions. The presence of the hormone was shown to be necessary to maintain, in vitro, the synthesis of the first set of polypeptides and was strongly inhibitory, in vitro and in vivo, to the synthesis of the second set of polypeptides. Thus, it is likely that the activity of the two distinct groups of DNA puffs is under opposite 20-OH-ecdysone control mechanisms.
Assuntos
Dípteros/genética , Ecdisterona/farmacologia , Amplificação de Genes , Glândulas Salivares/fisiologia , Animais , DNA/genética , Regulação da Expressão Gênica no Desenvolvimento , Larva/crescimento & desenvolvimento , Biossíntese de Proteínas , Transcrição GênicaRESUMO
We present the molecular characterization of a gene of Bradysia hygida DNA puff B10 whose temporal expression in the salivary gland correlates with the puff expansion. The transcription unit of this gene, named BhB10-1, was mapped in a 2-kb EcoRI genomic fragment that is amplified in the salivary gland of late fourth instar larvae. Its 1.3-kb transcript undergoes poly-A tail shortening during development, indicating that post-transcriptional controls as well as transcription activation are involved in the temporal regulation of the BhB10-1 gene. Analysis of the deduced amino acid sequence from the cDNA indicates that the BhB10-1 protein is a glycine-rich secretory protein. A BhB10-1-fusion protein expressed in bacteria was used to raise polyclonal antibodies. Using an immunopurified antibody, we identified the product of the DNA puff BhB10-1 gene as a 23-kDa polypeptide that is produced mainly by the salivary gland regions S1 and S3 and is present in the saliva of late larvae. This is the first direct identification of a protein encoded by a DNA puff amplified gene.
Assuntos
Genes de Insetos , Glicina/análise , Proteínas de Insetos , Insetos/genética , Larva/metabolismo , Glândulas Salivares/metabolismo , Proteínas e Peptídeos Salivares/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , DNA , DNA Complementar , Insetos/embriologia , Dados de Sequência Molecular , Glândulas Salivares/embriologia , Proteínas e Peptídeos Salivares/química , Proteínas e Peptídeos Salivares/metabolismo , Transcrição GênicaRESUMO
When the first group of DNA puffs is active in the salivary gland regions S1 and S3 of Bradysia hygida larvae, there is a large increase in the production and secretion of new salivary proteins demonstrable by [3H]-Leu incorporation. The present study shows that protein separation by SDS-PAGE and detection by fluorography demonstrated that these polypeptides range in molecular mass from about 23 to 100 kDa. Furthermore, these proteins were synthesized mainly in the S1 and S3 salivary gland regions where the DNA puffs C7, C5, C4 and B10 are conspicuous, while in the S2 region protein synthesis was very low. Others have shown that the extent of amplification for DNA sequences that code for mRNA in the DNA puffs C4 and B10 was about 22 and 10 times, respectively. The present data for this group of DNA puffs are consistent with the proposition that gene amplification is necessary to provide some cells with additional gene copies for the production of massive amounts of proteins within a short period of time.
Assuntos
Dípteros/genética , Biossíntese Peptídica/genética , Glândulas Salivares/fisiologia , Animais , Sondas de DNA , Feminino , Amplificação de Genes/genética , Saliva/químicaRESUMO
The endocytic pathway of Tritrichomonas foetus, a parasitic protozoan of cattle, was studied using (a) vital dyes, such as Lucifer yellow, neutral red and acridine orange, (b) cationized ferritin, (c) gold-labeled lactoferrin and lectins: HPA, UEA, PNA and LPA, and (d) DAMP (3-(2,4-dinitroanilino) 3' amino-N-methyldipropylamine). Light and confocal laser microscopy as well as transmission electron microscopy were used in this study. Assays were monitored by fluorescence and electron microscopy after exposing the parasites to different conditions. Cells that were incubated at 15 degrees C or 20 degrees C with gold-labeled lactoferrin and processed for electron microscopy show that of 15 degrees C this ligand is found only in an early endosomal compartment and at 20 degrees C it is found in late endosomes but not in lysosomes. Immunocytochemical data from cryosections using DAMP as a pH probe show that T. foetus has acidic compartments, with a pH range of 5.2 to 6.6, with variable morphology, localization and size. Lectin-binding sites and anionic sites were also internalized and appear to be associated with membranes lining the vacuoles. Images of patching and shedding of these sites were also observed when HPA and UEA were used.
Assuntos
Compartimento Celular , Citoplasma/química , Endocitose , Tritrichomonas foetus/citologia , Animais , Carboidratos/química , Bovinos , Membrana Celular/química , Dinitrobenzenos/metabolismo , Concentração de Íons de Hidrogênio , Indicadores e Reagentes/metabolismo , Cinética , Lactoferrina/metabolismo , Masculino , Microscopia Confocal , TemperaturaRESUMO
We report on a family in which the autosomal dominant Werner syndrome (WS) (MIM# 188770) affects ten members in three generations. Besides the absent tibiae the propositus had duplication of the fibulae. Possible pathogenetic mechanism is discussed.
Assuntos
Anormalidades Múltiplas/genética , Osso e Ossos/anormalidades , Polidactilia/genética , Adolescente , Adulto , Fíbula/anormalidades , Genes Dominantes , Humanos , Lactente , Masculino , Linhagem , Síndrome , Polegar/anormalidades , Tíbia/anormalidadesRESUMO
We report on a young girl with psychomotor delay, cataracts, abnormally shaped teeth, malformed ears, and radiological findings of spondylo-epiphyseal dysplasia. The clinical picture resembles the CODAS syndrome described by Shebib et al. [Am J Med Genet 40: 88-93, 1991].
Assuntos
Anormalidades Múltiplas/diagnóstico por imagem , Osteocondrodisplasias/diagnóstico por imagem , Anormalidades Múltiplas/genética , Pré-Escolar , Feminino , Humanos , Osteocondrodisplasias/genética , RadiografiaRESUMO
Misoprostol, a synthetic analog of prostaglandin, has been widely used in Brazil as an abortifacient. Abortion is illegal in Brazil. An uncertain number of these abortion attempts are unsuccessful and the pregnancy continues. We report on 7 patients whose mothers attempted to abort using this drug in the first trimester of gestation without success. The 7 patients presented with limb defects and in 4 of them a diagnosis of Möbius sequence was made.
Assuntos
Anormalidades Induzidas por Medicamentos , Anormalidades Múltiplas/induzido quimicamente , Doenças dos Nervos Cranianos/congênito , Ectromelia/induzido quimicamente , Paralisia Facial/congênito , Misoprostol/efeitos adversos , Aborto Criminoso , Brasil , Doenças dos Nervos Cranianos/induzido quimicamente , Paralisia Facial/induzido quimicamente , Feminino , Deformidades Congênitas do Pé/induzido quimicamente , Deformidades Congênitas da Mão/induzido quimicamente , Humanos , Recém-Nascido , Masculino , Gravidez , SíndromeRESUMO
We report here the isolation and characterization of a 2.3 kb genomic EcoRI fragment that co-localizes in the DNA puff C4 of Bradysia hygida with a 4 kb EcoRI fragment previously characterized as containing part of a gene amplified and expressed in the salivary gland at the time when puff C4 expands. Verification of the relative amount of DNA complementary to these two genomic fragments shows that they are unequally amplified in the salivary gland. The fragment containing part of the gene expressed when puff C4 expands amplifies about eight times more than the 2.3 kb fragment. This 2.3 kb fragment also carries sequences complementary to RNA species present in the gland in a period when puff C4 has already receded. Based on these data we discuss the nature of the DNA puff and the possible way in which amplification is occurring at these sites.
Assuntos
Dípteros/genética , Amplificação de Genes , Animais , Southern Blotting , Cromossomos/ultraestrutura , DNA/genética , DNA/isolamento & purificação , Desoxirribonuclease EcoRI , Feminino , Hibridização in Situ Fluorescente , Larva , Mapeamento de Peptídeos , RNA/isolamento & purificação , Glândulas Salivares/citologiaRESUMO
We report on a boy with severe radial hypoplasia, absent thumbs and patellae, short stature, persistent diarrhea, slender nose and normal intelligence as another example of the RAPADILINO syndrome.
Assuntos
Anormalidades Múltiplas , Nanismo , Face/anormalidades , Comunicação Interatrial , Deformidades Congênitas dos Membros , Anormalidades Múltiplas/patologia , Canal Anal/anormalidades , Criança , Humanos , Masculino , Patela/anormalidades , SíndromeRESUMO
A recombinant clone carrying a 2-kb fragment was isolated from a mini-library of the B10 DNA puff of Bradysia hygida. This fragment was amplified in the salivary gland during the period of DNA puff formation. Amplification started when DNA puff anlage was formed and continued to increase, reaching a maximum of about 10-fold 28 h later. Northern blot hybridization experiments showed that this 2-kb fragment was complementary to two RNA species of about 1.3 kb and 1.1 kb, which are developmentally regulated in the salivary gland. Maximum amounts of these messages were present when the B10 puff is fully expanded.
Assuntos
Cromossomos/ultraestrutura , Clonagem Molecular/métodos , DNA/genética , Dípteros/genética , Amplificação de Genes/genética , Regulação da Expressão Gênica/genética , Glândulas Salivares/ultraestrutura , Animais , Sequência de Bases , Northern Blotting , Dípteros/crescimento & desenvolvimento , Biblioteca Gênica , Hibridização In Situ , Larva/genética , Larva/crescimento & desenvolvimento , Recombinação Genética/genéticaRESUMO
Three XX males, two XX true hermaphrodites, and an XY female were studied for possible deletions using probes for the recently characterised SRY gene and the pseudoautosomal boundary. The XX males and true hermaphrodites were negative for all three probes, while the XY female was positive. One XX male and one XX true hermaphrodite were sibs. A previous sib pair of an XX male and an XX true hermaphrodite have been shown to be positive for Y chromosomal material near the pseudoautosomal boundary. Thus, both phenotypes can be produced from different mutations, some involving the SRY gene and others not.
Assuntos
Deleção Cromossômica , Sondas de DNA , Transtornos do Desenvolvimento Sexual/genética , Genes , Aberrações dos Cromossomos Sexuais/genética , Análise para Determinação do Sexo , Cromossomo X , Cromossomo Y , Adolescente , Southern Blotting , Pré-Escolar , Passeio de Cromossomo , Feminino , Humanos , Masculino , Fenótipo , Diferenciação Sexual/genética , Testículo/embriologiaRESUMO
Two sibs with a phenotype characterised by short stature, brachydactyly, and ocular anomalies (Peters' anomaly) are reported (Peters'-plus syndrome). The consanguinity is in agreement with the proposed autosomal recessive inheritance.
Assuntos
Córnea/anormalidades , Genes Recessivos , Transtornos do Crescimento/genética , Pré-Escolar , Consanguinidade , Feminino , Humanos , Lactente , Masculino , Fenótipo , SíndromeRESUMO
Rabbits were injected either intravitreally or intra-aqueously with L-[3H]-fucose and killed at several intervals after the administration of this marker for glycoproteins. The aqueous humor, the vitreous body and the ciliary body were processed for radiometry (liquid scintillation counting), sodium dodecyl sulfate-poly-acrylamide gel electrophoresis (SDS-PAGE) and fluorography. Light microscopic autoradiography was carried out on semi-thin sections of the ciliary body and revealed intense activity in terms of the synthesis, migration and renewal of glycoproteins in the ciliary epithelium. The amount of unbound [3H]-fucose in the aqueous humor decreased sharply by 4 h, and the labeled glycoproteins were present only in very small quantities at 1 day after the intra-aqueous injection. When [3H]-fucose was injected intravitreally, unbound radiolabel could be detected in the aqueous humor for greater than 1 day and the labeled glycoproteins, for up to 21 days after injection. The amount of unbound or bound [3H]-fucose was higher in the vitreous than in the aqueous at any interval after the intravitreal injection. Following the intra-aqueous injection, the amount of label that reached the vitreous body was practically insignificant. The levels of radioactivity in the serum were extremely low, as they were in the contralateral eye when tritiated fucose was injected into one eye only. Most of the Coomassie blue-stained bands detected in SDS-PAGE contained labeled glycoproteins as revealed by fluorography of gels simultaneously containing aqueous and vitreous samples.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Humor Aquoso/metabolismo , Proteínas do Olho/metabolismo , Glicoproteínas/metabolismo , Animais , Autorradiografia , Corpo Ciliar/metabolismo , Eletroforese em Gel de Poliacrilamida , Coelhos , Radiometria , Corpo Vítreo/metabolismoRESUMO
A de novo t(4;22)(q1200;p13) is reported in a girl with a florid 4p trisomy phenotype. The abnormal chromosome was identified by high resolution, C-bands and confirmed by 5-BrdU as de novo dicentric translocated chromosome.
Assuntos
Cromossomos Humanos Par 4 , Translocação Genética/genética , Trissomia , Adolescente , Feminino , Humanos , CariotipagemRESUMO
L-[3H]fucose was injected intravitreally into rabbits that were killed from 1 hr to 28 days after injection. The vitreous bodies were processed for radiometric techniques, and electrophoresis followed by fluorography. Unbound [3H]fucose remained at a high level up to 1 day, whereas the peak of [3H]fucose bound to glycoproteins was observed at 3 days after injection with a continuous decrease afterwards. The turnover rate of vitreous glycoproteins was estimated at 4.37% per day and their turnover time at 22.85 days. Electrophoresis and fluorography combined revealed about 14 bands of glycoproteins with fucose residues and there were strong indications of differences in turnover rate among individual glycoproteins. The most prominent band in the Coomassie blue-stained gels was the one having a molecular weight of 69 kDa and it was not labeled with [3H]fucose. This band was tentatively identified as serum albumin. On the other hand, the 14 bands labeled with [3H]fucose were glycoproteins originating from within the eye, that is, they are intrinsic constituents of the vitreous body.
Assuntos
Glicoproteínas/metabolismo , Corpo Vítreo/metabolismo , Animais , Eletroforese em Gel de Poliacrilamida , Glicoproteínas/análise , Masculino , CoelhosRESUMO
A cartilage matrix glycoprotein (CMGP), previously identified in human and bovine vitreous, now has been found in the vitreous body of rabbits aged 1-22 months by immunohistochemical techniques. Epithelial cells of the inner layer of the ciliary epithelium contain material that has immunologic cross-reactivity with a specific antibody to CMGP. These cells also secrete glycoproteins, as determined by autoradiography after intravitreal injection of [3H]fucose. Approximately 14 bands, representing intrinsic glycoproteins containing fucose residues, can be identified in fluorograms of SDS-polyacrylamide gels of vitreous bodies from 6- and 22-month-old rabbits. Fluorograms of gels of samples of vitreous and ciliary bodies from several time points after intravitreal injection of [3H]fucose reveal at least seven comigrating protein bands and also demonstrate turnover of the labeled ciliary body glycoproteins. These results suggest that the inner layer of the ciliary epithelium is the source of the glycoproteins of the vitreous body and that these glycoproteins undergo turnover, probably throughout the entire life of the animals.
Assuntos
Proteínas do Olho/análise , Corpo Vítreo/análise , Animais , Antígenos/análise , Autorradiografia , Corpo Ciliar/análise , Epitélio/análise , Feminino , Técnicas Imunoenzimáticas , Masculino , CoelhosRESUMO
The authors present the clinical and cytogenetic studies of a white malformed baby with dup (3p) secondary to the malsegregation of a maternal balanced (X;3) (p22.3;p21) translocation. Besides the typical clinical features he also presented polydactyly of both hands. X-replication findings of the mother's lymphocytes did not strictly follow the usual inactivation pattern of balanced X;A translocations.