We conducted an experiment and let a bar eye male mate with normal eye vergine female. The results of different members in the group make us confused. I get 4 flies with Bar eyes, my colleague get 20 flies with eyes like what in the attached pictures. we are confused if what is in the picture is bar or normal?
https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-xpt1/v/t34.0-12/11150282_978901195455291_5325775358325902954_n.jpg?oh=fac5c5ec3982cd00f60cb538dc559fd7&oe=552CE7FF&__gda__=1428988982_ec655ccf641da82e29d93fe7496827f8
https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-xpf1/v/t34.0-12/10372744_978901202121957_6618028727227451125_n.jpg?oh=10550f4ecb6186a670abca85cda6a7c7&oe=552CDDE0&__gda__=1428977631_9f4931a362f9554dd65e2c43bcb5c5e9
Dear Esraa,
The Bar phenotype with respect to the eye is a dominant phenotype and the eye in the pictures you sent is indeed exhibiting the phenotype, I suspect in a female heterozygote.
I suspect you might be getting confused by the the difference in phenotypes between hemizygotes, homozygotes and heterozyogotes. Keep in mind that the mutant allele is on the X chromosome. Therefore your original male is hemizygous for the Bar mutation; it has only one X chromosome, and the Bar gene on it is the mutant allele. Your females (XX) from this cross will be heterozygotes, that is they will have one wild-type copy of the Bar gene, and one mutant allelle of it. The phenotype will not be as severe as in the original male parent because of the extra presence of the wild-type allele, but it should still be distinguishable (kidney bean shaped with that nick/notch in it) from wild-type fly eyes.
I am attaching an image from Lindsey and Zimm (1992) which illustrates the difference between the phenotypes in heterozygous females (left) and hemizygous males (right).
I hope this helps. Good luck with your research.
Shaad
Bar eye is X-linked and dominant (agree with Shaad's answer) in that a heterozygous female will have kidney shaped eyes. If you have a Bar/+ female crossed to a Bar/Y male, then you should get some homozygous Bar/Bar females that have eyes looking like the male, with the strong Bar phenotype (the smallest eye). Good Luck
I would like to ask 1) Do you know what allele of Bar you are using? 2) Are you working with a balancer chromosome like FM7? 3) Do you have access to the FlyBase website?
If you do, then you can search for Bar on flybase and read about it there.
The spontaneous mutation Bar1 has a visible dominant phenotype and is the common Bar eye mutation associated with the FM balancer chromosomes. This allele is what Bar was named for and hence it is written with a capital letter "B" which indicates dominance. It is also true that Bar has alleles (mutations) that are not dominant visible but that are recessive lethal. This is probably not what you are working with given that you started with a male that is alive with a Bar eye phenotype. Hope this helps.
http://flybase.org/reports/FBgn0000154.html
Beth Stronach If Bar eye is X linked and dominant then what is the genotype for kidney shaped eyes?
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