266
Organ Culture
3. Wash the disc in fresh physiological solution, and remove any tissues
attached to the disc.
4. Cut the disc in half.
Implantation 1. Inject a disc fragment into the abdomen of a freshly emerged female
adult using a capillary or syringe while the female is anesthetized with
CO2•
Passage 1. After 1 or 2 weeks, excise the implanted disc, and cut it into several
pieces in physiological solution.
2. Implant each disc fragment into the abdomen of a different female
individual.
3. Repeat steps 1 and 2 continuously (Fig. 9) .
• • Results
Cells from imaginal discs stop dividing early in metamorphosis, because
the onset of differentiation brings any mitotic activity to an end. However, when these cells are transferred directly from the larva into an adult
body, thus avoiding metamorphosis, they undergo unlimited division.
According to Hadorn (1964), the cells of an implanted disc multiply in
the body cavity of the host. The proliferating cells do not lose their competence for differentiation, even after many passages. If the multiplied
cells are transplanted back into a metamorphosing host (such as a
prepupae), they form completely normal adult structures when the host
metamorphoses.
Imaginal
Donner larva
d;K~~ "J
SAH-1
~
TAH
112
M~
'~r-+D A~~AT
Differ
LH
~T
Differ
Fig. 9. Method for the permanent culturing imaginal discs from Drosophila
melanogaster in vivo. AT, adult tissues; Differ, differentiation; LH, larval host; Met,
metamorphosis; Proli, proliferation; SAH-l, the first-generation stem-line adult host;
SAH-2, the second-generation adult host; TAH, test adult host. Modified after Hadom
(1963) with permission of Academic Press
Organ Culture
3. Wash the disc in fresh physiological solution, and remove any tissues
attached to the disc.
4. Cut the disc in half.
Implantation 1. Inject a disc fragment into the abdomen of a freshly emerged female
adult using a capillary or syringe while the female is anesthetized with
CO2•
Passage 1. After 1 or 2 weeks, excise the implanted disc, and cut it into several
pieces in physiological solution.
2. Implant each disc fragment into the abdomen of a different female
individual.
3. Repeat steps 1 and 2 continuously (Fig. 9) .
• • Results
Cells from imaginal discs stop dividing early in metamorphosis, because
the onset of differentiation brings any mitotic activity to an end. However, when these cells are transferred directly from the larva into an adult
body, thus avoiding metamorphosis, they undergo unlimited division.
According to Hadorn (1964), the cells of an implanted disc multiply in
the body cavity of the host. The proliferating cells do not lose their competence for differentiation, even after many passages. If the multiplied
cells are transplanted back into a metamorphosing host (such as a
prepupae), they form completely normal adult structures when the host
metamorphoses.
Imaginal
Donner larva
d;K~~ "J
SAH-1
~
TAH
112
M~
'~r-+D A~~AT
Differ
LH
~T
Differ
Fig. 9. Method for the permanent culturing imaginal discs from Drosophila
melanogaster in vivo. AT, adult tissues; Differ, differentiation; LH, larval host; Met,
metamorphosis; Proli, proliferation; SAH-l, the first-generation stem-line adult host;
SAH-2, the second-generation adult host; TAH, test adult host. Modified after Hadom
(1963) with permission of Academic Press