RESUMO
A cDNA subtraction and differential hybridization strategy was used to isolate cDNAs expressed early during male gametophyte development in the important crop species Brassica napus. Three cDNAs, corresponding to genes highly and specifically expressed at the tetrad and microspore stages, are presented here. The analysis of one of them, named BnM3.4, by in situ hybridization, showed that it is expressed specifically and at a high level in the rapeseed microspore. The specificity in its profile of expression is most likely transcriptionally controlled as a similar pattern of expression was also observed in Arabidopsis thaliana plants transformed by the BnM3.4 promoter fused to the reporter GUS-coding sequence. The putative BnM3.4 promoter contains three dispersed copies of a motif described previously in the promoters of several genes expressed in the male gametophyte. The BnM3.4 gene encodes a predicted novel proline-rich protein of 23.4 kDa which may interact with cytoskeletal components or have a structural role in the cell wall.
Assuntos
Brassica/genética , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Proteínas de Plantas/genética , Arabidopsis/genética , Sequência de Bases , Brassica/crescimento & desenvolvimento , Brassica/fisiologia , DNA Complementar , Regulação da Expressão Gênica no Desenvolvimento , Genes Reporter , Glucuronidase/genética , Hibridização In Situ , Dados de Sequência Molecular , Proteínas de Plantas/biossíntese , Proteínas de Plantas/química , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas , Reprodução , Mapeamento por Restrição , Alinhamento de Sequência , Homologia de Sequência do Ácido NucleicoRESUMO
The exon d of nad1 is located 993 bp upstream of the nad6 gene in the wheat mitochondrial genome. Transcription analyses of both sequences (nad1 exon d and the nad6 gene) were done by Northern hybridization using RNA from wheat seedlings and tissue cultures derived from immature embryos. A complicated pattern was generated with a probe including exon d of nad1 and the whole nad6 gene. An 0.71-kb transcript is specific to nad1 exon d whereas a 1.2-kb transcript is specific to the nad6 gene. Three larger transcripts hybridize to both probes suggesting that nad1 exon d and nad6 are co-transcribed. This co-transcription has been directly demonstrated by cDNA synthesis on mtRNAs and sequencing of the PCR amplification product.
Assuntos
Éxons , Genes de Plantas , Mitocôndrias/enzimologia , NAD(P)H Desidrogenase (Quinona)/genética , Triticum/enzimologia , Triticum/genética , Sequência de Bases , Células Cultivadas , Primers do DNA , Expressão Gênica , Íntrons , Dados de Sequência Molecular , NAD(P)H Desidrogenase (Quinona)/biossíntese , Conformação de Ácido Nucleico , Reação em Cadeia da Polimerase , RNA/biossíntese , RNA/química , RNA/metabolismo , Splicing de RNA , RNA Mitocondrial , Transcrição GênicaRESUMO
A region of the mitochondrial (mt) DNA of wheat was studied because of its homology with other plant mtDNAs. Sequence analysis revealed an open reading frame encoding a polypeptide of 247 amino acids. Comparison of the sequence of the putative polypeptide with the protein sequence data of the Swiss-Prot library reveals homology with subunit 6 of the NADH-ubiquinone complex of mitochondria from Marchantia polymorpha, Podospora anserina, Chlamydomonas reinhardtii and of chloroplasts from M. polymorpha and Oryza sativa. No similarity was detected when compared with the subunit 6 of animal mitochondria, probably due to the rapid evolution of the sequence. A single 1.2 kb transcript appears in northern RNA blots. We found 15 edited sites of which only 13 give amino acid changes. This is the first report of a mt nad6 gene in higher plants.
Assuntos
Genes de Plantas/genética , Mitocôndrias/fisiologia , NAD(P)H Desidrogenase (Quinona)/genética , RNA Mensageiro/genética , Triticum/genética , Sequência de Aminoácidos , Sequência de Bases , Genoma , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos , Transcrição Gênica , Triticum/enzimologiaRESUMO
We report a case of Rosaï-Dorfman Disease revealed by renal failure in a 43 years old patient. Clinical presentation included abdominal lymphadenopathy and general status deterioration. Diagnosis was established by histopathological examination of the node which revealed sinusal lymphohistiocytosis. Treatment combined prednisone and cyclophosphamide and was effective with regression of renal failure. We will review the diagnostic criteria and the prognosis of this disorder of unknown etiology.