81 research outputs found
The common nodulation genes of Astragalus sinicus rhizobia are conserved despite chromosomal diversity
The nodulation genes of Mesorhizobium sp. (Astragalus sinicus) strain 7653R were cloned by functional complementation of Sinorhizobium meliloti nod mutants. The common nod genes, nodD, nodA, and nodBC, were identified by heterologous hybridization and sequence analysis. The nodA gene was found to be separated from nodBC by approximately 22 kb and was divergently transcribed. The 2.0-kb nodDBC region was amplified by PCR from 24 rhizobial strains nodulating A. sinicus, which represented different chromosomal genotypes and geographic origins. No polymorphism was found in the size of PCR products, suggesting that the separation of nodA from nodBC is a common feature of A. sinicus rhizobia. Sequence analysis of the PCR-amplified nodA gene indicated that seven strains representing different 16S and 23S ribosomal DNA genotypes had identical nodA sequences. These data indicate that, whereas microsymbionts of A. sinicus exhibit chromosomal diversity, their nodulation genes are conserved, supporting the hypothesis of horizontal transfer of nod genes among diverse recipient bacteria
Continuously elevated serum matrix metalloproteinase-3 for 3 ~ 6 months predict one-year radiographic progression in rheumatoid arthritis: a prospective cohort study
Tomography Analysis Of Fiber Distribution And Orientation In Ultra High-Performance Fiber-Reinforced Composites With High-Fiber Dosages
Les techniques de rehabilitation des domaines skiables - Compte rendu de stage
SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : GR 1637 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc
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