RESUMO
We previously reported a rat chromosomal origin of DNA replication (oriA1) that encompassed the aldolase B (AldB) gene promoter. Here, we examined utilization of oriA1 in AldB-expressing and non-expressing cells. The results suggested the occurrence of mutually exclusive regulation between DNA replication and transcription. Nascent strand abundance as assayed by competitive polymerase chain reaction using bromodeoxyuridine-labeled nascent DNA indicated that oriA1 is not utilized in AldB-expressing cells, while it is fired in non-expressing cells. In the latter non-expressing cells, the replication fork seemed to slow at 20-22 kb downstream of oriA1.
Assuntos
Replicação do DNA , Frutose-Bifosfato Aldolase/biossíntese , Frutose-Bifosfato Aldolase/genética , Animais , Antimetabólitos Antineoplásicos/farmacologia , Bromodesoxiuridina/farmacologia , Immunoblotting , Modelos Genéticos , Reação em Cadeia da Polimerase , Regiões Promotoras Genéticas , Ratos , Transcrição Gênica , Células Tumorais CultivadasRESUMO
beta-conglycinin, a soybean seed storage protein, is comprised of three different subunits, a, alpha', and beta. Several candidates for the alpha subunit gene have been isolated, however, the structure of the alpha subunit gene has not been completely determined. Accordingly, it was also unknown which of the gene candidates are functionally active. Here, we have determined the nucleotide sequence and transcription start site of the alpha subunit gene, and compared the structural components with those of the other subunits or other seed protein genes. The a subunit gene, which is located on a 7.6-kb EcoRI fragment, was composed of six exons that had the same organization as those for the alpha' subunit gene. Within a 400 bp upstream region of the transcription start site, four regions (designated as boxes I, II, III, and IV) were found to be conserved among the alpha, alpha', and other seed protein genes. Genomic Southern blot analysis of soybean varieties lacking the alpha subunit gene candidate indicated that the gene characterized in this paper actually encodes the a subunit and is functionally active. In addition, these experiments revealed the presence of an additional gene which is also responsible for the expression of the a subunit.
Assuntos
Globulinas/genética , Glycine max/genética , Proteínas de Soja , Sequência de Aminoácidos , Antígenos de Plantas , Sequência de Bases , Southern Blotting , Éxons , Íntrons , Modelos Genéticos , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , RNA/metabolismo , RNA Mensageiro/metabolismo , Proteínas de Armazenamento de Sementes , Análise de Sequência de DNA , Homologia de Sequência do Ácido Nucleico , Transcrição GênicaRESUMO
Because it is difficult to identify morphologically the Japanese forms of Fasciola, additional taxonomic criteria are required. In order to clarify the genetic relationships between Fasciola hepatica, Fasciola gigantica, and the Japanese triploid forms of Fasciola, we compared nucleotide sequences of mitochondrial NADH dehydrogenase subunit 1 (ND1) and cytochrome c oxidase subunit I (COI) genes. Intraspecific variation in the ND1 and COI sequences was low, except for 1 specimen of F. gigantica in the ND1 sequence. The ND1 and COI sequences of Japanese triploid forms of Fasciola were nearly identical to those found in F. gigantica but were different from those of F. hepatica. Thus, the Japanese triploid forms of Fasciola are thought to be categorized as F. gigantica.