Mapping of repetitive and non-repetitive DNA probes to chromosomes of the microsporidian Encephalitozoon cuniculi.
The molecular karyotype of a murine isolate of Encephalitozoon cuniculi, a microsporidian with a wide range of mammalian hosts, comprises eleven chromosomes ranging in size between 217 and 315 kb. To determine specific chromosomal markers, a partial genomic library was constructed and cloned DNA fragments were hybridized to chromosomal bands separated by pulsed-field gel electrophoresis. Most probes were assigned to single chromosomes, indicating prevalence of low-copy number nucleotide sequences within the very small genome of E. cuniculi (2.9 Mb). A few probes were shown to hybridize to all chromosomes. These repetitive DNA fragments corresponded to either rRNA genes or some non-coding regions whose sequences were characterized by short micro- and minisatellites. The chromosomal locations of beta-tubulin genes and six newly identified protein-encoding genes were determined. Genes encoding dihydrofolate reductase, thymidylate synthase, serine hydroxymethyl transferase, a cdc2 kinase-like protein and helicase ERCC6-like protein were each located on a single chromosome whereas genes for both beta-tubulin and aminopeptidase were on two different chromosomes. The mapping will serve as a reference for further analysis of intraspecific karyotype polymorphism in different isolates from different host species.
Biderre
C
C
Laboratoire de Protistologie Moléculaire et Cellulaire des Parasites Opportunistes, URA CNRS 1944, Université Blaise Pascal, Aubière, France.
Duffieux
F
F
Peyretaillade
E
E
Glaser
P
P
Peyret
P
P
Danchin
A
A
Pagès
M
M
Méténier
G
G
Vivarès
C P
CP
D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D015342:DNA Probes; D018076:DNA, Complementary; D016054:DNA, Protozoan; D009670:Encephalitozoon cuniculi / Q000235:genetics*; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D012091:Repetitive Sequences, Nucleic Acid; D017422:Sequence Analysis, DNA
D015342:DNA Probes; D018076:DNA, Complementary; D016054:DNA, Protozoan