Bio 321 F13 lecture 3 v2

Morgan group at columbia in 1908

Info icon This preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: unfer0lized eggs) phenomenology of sex linkage in Drosophila melanogaster •  Thomas Hunt Morgan group at Columbia in 1908 –  male with white eyes discovered in a wild type (red eyed) strain •  mated this male to parental strain red eyed females •  all F1 progeny were red eyed •  mated red eyed female F1 to (parent or brother) red eyed male –  female F2: 100% red eyed –  male F2: 50% red eyed, 50% white eyed •  mated F1 male (red eyed) to parental strain red eyed female –  all progeny of both sexes were red eyed •  The muta0on, which Morgan called white, was linked to maleness in this cross; it was sex- linked hZp://en.wikipedia.org/wiki/Thomas_Hunt_Morgan hZp://diogenesii.files.wordpress.com/2010/07/lewis- 16.gif hZp://nobel.caltech.edu/ hZp://991.com/newGallery/Burl- Ives- Song- Book- 294106.jpg hZp://fcdn.filmonic.netdna- cdn.com/wp- content/uploads/2008/03/nedflanders.JPG how did Morgan get white eyed females? •  mate white eyed F1 males to red eyed females whose fathers were white eyed –  males: 50% red eyed, 50% white eyed –  females: 50% red eyed, 50% white eyed hZp://www.schooltr.com/Teacher_Resources/Lesson_Plans/ Lesson_Plan_images/Drowsy_Drosophila27.jpg sex chromosome PunneZ square female gametes X 50% 25% X male gametes 50% XX ♀ 25% Y 50% XY ♂ X 50% 25% XX ♀ 50% females 25% XY ♂ 50% males Drosophila melanogaster white wild type female gametes X+ 50% X+ 50% 25% white- eyed male gametes Xw 50% 25% 25% 25% X+Xw X+Xw ♀ ♀ X+Y X+Y Y ♂ 50% ♂ females: 100% red eyed (all X+Xw heterozygotes) males 100% red eyed (all X+Y hemizygotes) next genera0on (F1 cross) heterozygous female gametes X+ 50% Xw 50% 25% wild type male gametes X+ 50% 25% 25% 25% X+X+ X+Xw ♀ ♀ X+Y XwY Y ♂ 50% ♂ overall Ÿ༉50% of offspring will be red eyed females Ÿ༉25% of offspring will be red eyed males Ÿ༉25% of offspring will be white eyed males females: 100% red eyed Ÿ༉50% are X+X+ homozygotes Ÿ༉50% are X+Xw heterozygotes males 50% red eyed Ÿ༉X+Y hemizygotes 50% white eyed Ÿ༉XwY hemizygotes to generate white eyed females heterozygous female gametes X+ 50% Xw 50% 25% white eyed male gametes Xw 50% 25% 25% 25% X+Xw XwXw ♀ ♀ X+Y XwY Y ♂ 50% ♂ overall Ÿ༉25% of offspring will be red eyed females Ÿ༉25% of offspring wi...
View Full Document

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern