Additionally, simultaneous excision repair of damaged or inappropriate bases incorporated in DNA that are in proximity and on opposite complementary DNA strands may lead to DNA double-stranded breaks and micronucleus formation, especially if the gap-filling step of the repair pathway is not completed.
42.
The term "'micronucleus "'may also refer to the smaller conjugation it furnishes the pairing of gamete nuclei, by whose reciprocal fusion a zygote nucleus is formed, which gives rise to the macronuclei and micronuclei of the individuals of the next cycle of fission.
43.
As a ciliated protozoan, " "'Tetrahymena thermophila " "'exhibits nuclear dimorphism : two types of cell non-germline macronucleus and a small, germline micronucleus in each cell at the same time and they both carry out different functions with distinct cytological and biological properties.
44.
After a brief period of co-stimulation ( ~ 1hr ), starved cells begin to pair at their anterior ends to form a specialized region of membrane called the conjugation junction . thumbnail It is at this junctional zone that several hundred fusion pores form, allowing for the mutual exchange of protein, RNA and eventually a meiotic product of their micronucleus.
45.
Unlike some other ciliates, " C . uncinata " contains millions of minichromosomes ( somatic chromosomes ) in its macronucleus while its micronucleus is estimated to contain 3 chromosomes . " Childonella uncinata " is the causative agent of Chilodonelloza, a disease that affects the gills and skin of fresh water fish, and may act as a facilitative parasite of mosquito larva.
