Electrophoretic karyotyping and construction of a bacterial artificial chromosome library of the winter mushroom Flammulina velutipes

SummaryAn electrophoretic karyotype of Korean Flammulina velutipes was obtained using contour-clamped homogeneous electric field (CHEF) gel electrophoresis. The monokaryotic progenies (4019-20 and 4019-18) and a dikaryotic strain (4019-2018) had 6–8 chromosomes, with sizes ranging from 1.6 to 5.8 megabase (Mb) pairs. Among the 3 strains that were examined, strain 4019-20 resolved into at least 7 chromosomes, with a total genome size of approximately 26.7 Mb. We selected several chromosome-specific genes from the cDNA library of F. velutipes using Southern hybridization analysis. In order to determine the whole genome sequence, we constructed a bacterial artificial chromosome (BAC) library of the 4019-20 strain. The BAC library comprised 3840 clones, and the insert size ranged from 60 to 228 kb, with an average size of 136 kb.