Abstract
The molecular karyotype of the coccidial parasiteEimeria tenella has been further resolved. Different conditions of pulsed-field gel electrophoresis were used to separate up to 14 chromosomes that ranged in size between 1 and in excess of 6 megabase pairs (Mb) of DNA. Comparisons of several populations revealed some size polymorphisms of homologous chromosomes. Probes containing tandem repeats of the DNA sequence CAG and the telomeric-like sequence TTTAGGG hybridised to each chromosome. All other probes containing either repetitive or non-repetitive sequences were mapped to individual chromosomes.