Transformation with Artificial Chromosomes in and Their Applications.

, like other ciliates, has separate germline and somatic nuclei. The diploid germline genome in the micronucleus is composed of long conventional chromosomes. The macronucleus contains a somatic genome which is naturally fragmented into thousands of kilobase-sized chromosomes.

(C) Gene Transfer between Strains Occurs by Homologous Recombination after Co-infection: Implications for Spread of Tetracycline-Resistance among .

is a swine pathogen that has also recently been found to cause zoonotic infections of the human eye, pharynx, and gastrointestinal tract. Many strains contain a tetracycline class C gene [(C)] cassette that confers tetracycline resistance. The cassette was likely originally acquired by horizontal gene transfer from a Gram-negative donor after the introduction of tetracycline into animal feed in the 1950s.