Organization of repetitive DNA sequences in the genome of the echinoderm Holothuria tubulosa.
The abundance of repetitive DNA in the haploid sea cucumber genome has been determined by screening a Holothuria genomic DNA library for clones containing repeated sequences using reverse genome hybridization. Analysis by in situ plaque hybridization of a set of 1132 clones has revealed the presence of repetitive DNA sequences in about 38.1% of the clones screened. The distribution of the reiterated DNA has been further analyzed by restriction endonuclease digestion of seven randomly selected repetitive clones. The repeated sequences have a fairly uniform distribution of lengths with an average length value of 7.3 kb. Analysis of the measurements suggests that the repetitive sequences are interspersed among longer single copy sequences with an average spacing interval of about 47.3 kb indicating that the repetitive and single copy DNA in the Holothuria genome are arranged in a long-period interspersion pattern.
Sainz
J
J
Department of Molecular and Cell Biology, Centro de Investigación y Desarrollo del CSIC, Barcelona, Spain.
Prats
E
E
Ruiz
S
S
Cornudella
L
L
D000818:Animals; D003001:Cloning, Molecular; D004247:DNA / Q000737:chemistry*; D015698:Genomic Library; D006238:Haploidy; D017403:In Situ Hybridization; D012091:Repetitive Sequences, Nucleic Acid; D015183:Restriction Mapping; D012616:Sea Cucumbers / Q000235:genetics*
D004247:DNA