title: Size and complexity of the nuclear genome of Colletotrichum graminicola.
abstract: DNA reassociation was used to estimate GC content, size, and complexity of the nuclear genomes of Colletotrichum from maize and sorghum. Melting-temperature analysis indicated that the GC content of the maize pathotype DNA was 51% and that the GC content of the sorghum pathotype was 52%. DNA reassociation kinetics employing S1 nuclease digestion and an appropriately modified second-order equation indicated that the genome sizes of the maize and sorghum pathotypes were 4.8 x 10(7) bp, and 5.0 x 10(7) bp, respectively. Genomic reconstruction experiments based on Southern blot hybridization between a cloned single-copy gene, PYR1 (orotate phosphoribosyl transferase), and maize-pathotype DNA confirmed the size of the nuclear genome. The single-copy component of the genomes of both pathotypes was estimated at about 90%. For both pathotypes, ca. 7% of the genome represented repetitive DNA, and 2 to 3% was foldback DNA.
authors.affiliation: Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907-1155, USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: Randhir
authors.forename: R M
authors.initials: RM
authors.lastname: Hanau
mesh_terms: D001482:Base Composition; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D002523:Edible Grain / Q000382:microbiology; D005800:Genes, Fungal; D016681:Genome, Fungal; D007700:Kinetics; D003904:Mitosporic Fungi / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D009695:Nucleic Acid Renaturation; D009962:Orotate Phosphoribosyltransferase / Q000235:genetics; D013816:Thermodynamics; D003313:Zea mays / Q000382:microbiology
chemical_list: D004271:DNA, Fungal; D009962:Orotate Phosphoribosyltransferase