Open AccessTransition of R‐ to I‐type in inbred lines of Drosophila melanogaster
Author(s) -
WU X.
Publication year - 1990
Publication title -
hereditas
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 50
eISSN - 1601-5223
pISSN - 0018-0661
DOI - 10.1111/j.1601-5223.1990.tb00066.x
Subject(s) - drosophila melanogaster , biology , mating type , genetics , type (biology) , recombination , line (geometry) , inbred strain , wild type , transition (genetics) , melanogaster , microbiology and biotechnology , gene , ecology , geometry , mathematics , mutant
In several branches derived from an inbred line of Drosophila melunogaster . transitions from R‐ to I‐type in the I‐R system have been observed. After a recent split into two batches of an R‐type +K subline, one branch showed, on retesting, an alteration to I‐type. Genome from the R‐type +K branch was introduced into two R‐type sublines with strong and fairly weak R‐reactivity, respectively. The original R‐type +‐K and the two new derivates were each split into five sublines. The new I‐type line was also split into five sublines. These fifteen R‐ and five I‐type sublines were repeatedly tested for about 50 generations. One of the R‐sublines with strong R‐reactivity changed to I‐type. None of the five I‐type sublines showed any change in the reaction pattern. Another line, which had been derived by recombination from an I‐type line, showed R‐type reaction in repeated tests. After 23 generations of mass‐mating, this line gave indications of inductivity in offspring from a single male. Subsequent splitting into five sublines confirmed that one of them rapidly switched to I‐type. The consequences are discussed in relation to the models proposed to explain the existence of R‐ and I‐lines.