An enzymatic comparison of two interbreeding but genetically isolated varieties of Paramecium aurelia
✍ Scribed by Levine, Myron
- Book ID
- 102881442
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1955
- Tongue
- English
- Weight
- 531 KB
- Volume
- 45
- Category
- Article
- ISSN
- 0095-9898
No coin nor oath required. For personal study only.
✦ Synopsis
The ciliated protozoan, Pnrawic uiiz nurcliu, can be divided into eight physiological species or varieties, each genetically isolated from the other. The mixing together of cultures of the complementary mating types of thesc varieties generally results in weak mating reactions, if they OCCLW at all; and when they lead to conjugation, gencrally gives rise to high F1 viability. Exceptions to this rule are the interactions of the stocks of varieties 4 and 8. ITnder optimum conditions, these intervarietal mating reactions are a s strong a s those occuning within a variety, yet thc F1 generation is almost coinplctely nonviable ( Sonnehorn and Diypell, '46a and 1, ; Sonnehorn, '47 and '30 ; lievine, ' 5 3 ) .
The mechanism, 011 the biological level, maintaining the genetic isolation of varieties 4 and 8 was rcccntly studied by Lcvinc ( ' 5 3 ) . Death of these intervarietal hybrids is due to a two way nucleo-cytoplasniic incornpa tibility system. Small amounts of cytoplasm of each variety are antagonistic to the normal development and fuiictioniny of the nuclei of
The followiiig nbbrevintioiis will hr, used : I)PK nut1 TPN, ilipliospliop?.ridiiie nuclcotide and tripliospliopSridine iiucleoti(1e respectivclu ; D P K H arid T P N H , rcdiicetl diI'liospliopyriilii1~ iiuclrotidr xiid reilurcd triphoiplio~~yritline iiucleotide ri~\l)c~ctivclv; DPS:rsr, d i ~~l ~o ~~~l i o p ~r i ~l i n r iiiirl(vtit1:rsc; ATP, ndc~nosiue tnpllospli:itc ; ATP:ihe, adciiosiiic tripliohpli:itnsc.
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