Article contents
New results on the genetics of mating types in Paramecium bursaria*
Published online by Cambridge University Press: 14 April 2009
Extract
1. The four mating-types I, II, III, IV known for P. bursaria, syngen 1 are determined by specific combinations of dominant and recessive alleles at two unlinked loci. Mating-type I is formed by cells with the genotypes AABB, AABb, AaBB and AaBb; type II is controlled by the genotypes aaBB and aaBb; the double recessive, aabb is type III, genotypes AAbb and Aabb bring about type IV.
2. Clones which are exceptions to these rules for mating-type determination occur in low frequency (2–3%) in one line of descent. All can be explained by assuming either a mutation of dominant gene B to its recessive allele b or to a loss of the B locus. The data suggest that in four clones, the macronuclear but not the micronuclear genotype is affected; in two clones both nuclei are aberrant.
3. The cytogenetic events of conjugation were verified by the use of the new genetic markers. No evidence for uniparental nuclear reorganization, autogamy, was found.
- Type
- Research Article
- Information
- Copyright
- Copyright © Cambridge University Press 1963
References
REFERENCES
- 17
- Cited by