wolodymyr (wolodymyr) wrote in biology,

Question about gametes produced by a Drosophila cross

I'm trying to put together three Drosophila crosses. I'm new at this, so I'm just getting the hang of nomenclature.

I've successfully done one. I'll use it as an example, and then, if you could, I would deeply appreciate your help figuring out the gametes of the other two.

BL7018 (Bloomington stock number 7018): w[*]; noc[Sco]/CyO; P{w[+mC]=tubP-GAL80[ts]}7

there are 3 genes here. w[*] means white eyes, noc[Sco]/CyO means curly wings and stubby bristles, and the 3rd, which I'll abbreviate Gal80ts, produces a temperature-sensitive Gal80 protein.

First question: Gal80ts has a mini-white marker on it. Does [+mC] indicate that marker?

There are 4 gametes possible from the male flies:
w; ScO; Gal80ts
w; CyO; Gal80ts
y; CyO; Gal80ts
y; CyO; Gal80ts

Second question: How do I determine the males' gametes for BL 7019, w[*]; P{w[+mC]=tubP-GAL80[ts]}20; TM2/TM6B? (Where w[*] is white eyes, P{ etc is the protein as above, and TM2/TM6B are balancers, meaning they're homozygous lethal. I don't know what phenotypes the heterozygotes show.)

Are they:
w; Gal80ts; TM2
w; Gal80ts; TM6B
y; Gal80ts; TM2
y; Gal80ts; TM6B


Third question: Pretty much the same thing for male fly gametes for BL 7016, P{w[+mC]=tubP-GAL80[ts]}9; w[*]/FM7c, where there seem to be two genes involved.

I'm a little more confused about this one, because I'm not exactly sure how the balancer FM7c works. Does it always have the phenotype bar eyes? Is it homozygous lethal, sterile? Can males carry it?

I was given a sample cross for this that I'm finding confusing. Here it is:


............\ Gal80ts...............FM7c..................Y



What confuses me is that it looks like all 3 of these genes are on the same chromosome (?) - so that the results are gene/gene, not gene;gene. Is Gal80 on X, here?

Also, (questions 8-10) what are the fates of these offspring? Is FM7c/Y viable? How do I recognize Gal80/Y? Are those all the males with normal-shaped eyes? And speaking of that, back to the gametes: the cross I was given doesn't include the mutant eye color. Should it?

Any confirmation, explanation, or instruction you could provide would be hugely appreciated.
  • Post a new comment


    default userpic
    When you submit the form an invisible reCAPTCHA check will be performed.
    You must follow the Privacy Policy and Google Terms of use.
  • 1 comment