Evolutionary DNA variation in the genus Hypochaeris

Citation
M. Cerbah et al., Evolutionary DNA variation in the genus Hypochaeris, HEREDITY, 82, 1999, pp. 261-266
Citations number
26
Categorie Soggetti
Biology,"Molecular Biology & Genetics
Journal title
HEREDITY
ISSN journal
0018067X → ACNP
Volume
82
Year of publication
1999
Part
3
Pages
261 - 266
Database
ISI
SICI code
0018-067X(199903)82:<261:EDVITG>2.0.ZU;2-#
Abstract
The genome size and the base composition (GC%) of sight Hypochaeris species were determined by flow cytometry in order to establish the pattern of nuc lear DNA variation within the genus. The species analysed showed an almost fivefold range of variation from 1.68 pg in H. cretensis to 8.10 pg in H. u niflora. This variation in DNA content is greater between taxonomic section s of Hypochaeris species than within a section. There was no correlation be tween 2C DNA content and GC% indicating that neither the GC fraction nor th e AT fraction were preferentially associated with variation in genome size. Because there is little heterochromatin, these results show that it is int erspersed repeated sequences that are most probably implicated in this vari ation. From phylogenetic analysis, it is likely that genome size has evolve d by loss of DNA content in some lineages and by gain in one lineage from a n ancestral genome which was probably similar to genomes of intermediate si ze in Hypochaeris.