. Contributions to the genetics of Drosophila melanogaster. Drosophila melanogaster; Heredity; Karyokinesis. GENES MODIFYING NOTCH. 300 FOURTH TEST (FOR FOURTH-CHROMOSOME MODIFIERS). The following method of findrng out whether a niodifyinfr j^cne it^ present m a particular chromosome was su^^ested by Dr. .\. 11. Sturte- vant. A short-Notch female is first crossed to a hhirk pink hcnt nuile. The Fi males^ are then crossed (in pairs) to stock short-Notdi females (see scheme below). Sladk. pinl^ I-x-tH 6 W Slioil Kotcli (. F„ Notch p b>' Short Notch O biy Blackpiukb«-nt O Since the Fi male had
. Contributions to the genetics of Drosophila melanogaster. Drosophila melanogaster; Heredity; Karyokinesis. GENES MODIFYING NOTCH. 300 FOURTH TEST (FOR FOURTH-CHROMOSOME MODIFIERS). The following method of findrng out whether a niodifyinfr j^cne it^ present m a particular chromosome was su^^ested by Dr. .\. 11. Sturte- vant. A short-Notch female is first crossed to a hhirk pink hcnt nuile. The Fi males^ are then crossed (in pairs) to stock short-Notdi females (see scheme below). Sladk. pinl^ I-x-tH 6 W Slioil Kotcli (. F„ Notch p b>' Short Notch O biy Blackpiukb«-nt O Since the Fi male had one fourth chromosome from black pink bent (and since there is no crossing -over in the male), half of his Notch (Fj) daughters will have this chromosome (only one each), and half will not have it. If they are of two sorts (so classified in table 12), such as intermediate and short Notch, their differences might depend on the presence of the bent fourth chromosome in half of the Notch females. If now we separate as far as possible the females into two classes, and Table 12.—Fi cf {out of short Notch 9 by hmt cf) by short Notch 9 . Normal 9. Short Notch ?. Interm. Notch 9. Eosin 9. Eosin Eo.«in- Notch 9. Nonual 1 9 2 15 66 21 / 22 I 12 4 13 12 27 68 41 28 30 28 .30 (2 al- most ata- vistic). 6 36 15 73 122 47 60 32 40 14 51 / 29 I 24 85 102 30 64 30 27 33 52 41 1 (intcrni.) •) 3 4 5 1 (sJiort) 6 7. 8 test each female separately to find out if she has or hiis not a l)ent fourth chromosome, we should get an answer to our question. Each female was bred to a black pink bent stock male. The presence of black, of pink, and of bent (separate or combined) in the offspring wiis recorded. Table 13 gives the end-results; the first column records the kind of F2 female tested, the next three columns the kind of notch, and the next three columns indicate (by X) whether l)lack. pink, or l>ent was present; and the last column the total number of fliei>. * Their sisters that were n
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectkaryoki, bookyear1919
