Određivanje oblika mutacije prema dobivenim rezultatima križanja vinske mušice Drosophila melanogaster

undergraduate thesis

• Title (english): Determining the shape of the mutation from results obtainedby crossing fruit fly Drosophila melanogaster
• Author: Marija Nimac
• Mentor: Lidija Šver (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Biochemical Engineering); (Laboratory for Biology and Microbial Genetics); Zagreb
• Defense date and country: 2012-09-13, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Cilj rada je bio, na osnovu broja potomaka križanja kroz nekoliko generacija, odrediti da li je mutacija bijele boje očiju u vinske mušice Drosophila melanogaster mutacija nasljednog svojstva vezana uz spol ili dvostruka autosomalna mutacija. Za potrebe križanja, u staklenke s prethodno pripremljenom podlogama nasađivali smo po 5 mužjaka i 5 djevičanskih ženki. Brojanjem potomaka križanja divljeg tipa mušica i bijelih mušica kroz nekoliko generacija utvrđena je dvostruka autosomalna mutacija jer su postignuta 4 različita fenotipa smeđe, crvene, grimizne i bijele oči. Crvena boja očiju vinske mušice (divlji tip) posljedica su taloženja dva pigmenta, smeđeg ksantomatina i svjetlo crvenog pigmenata drosopteridina. Geni w, st i bw kodiraju za ABC protein koji sudjeluje u transportu oba pigmenta. Mutacija oba gena, st i bw, koji kodiraju neispravni protein, uzrokuje bijele oči zbog nemogućnosti transporta pigmenta u pigmentne granule unutar stanica omatidija. Mutacija gena bw rezultira smeđim očima dok mutacija gena st rezultira grimiznim očima. Rezultati broja potomaka nije se poklopio sa očekivanim omjerom potomaka F2 generacije 9:3:3:1. Razlozi nepodudarnosti s omjerom su moguće pogreške u radu prilikom prepoznavanja smeđe i crvene boje očiju, križanje već oplođene mušice umjesto djevičanske zatim ovisnost proizvodnje pigmenta o temperaturi, sljepoća bijelih mušica te kompeticija za hranom. Osim određivanja mutacije mušica, provodili smo križanja s ciljem dobivanja homozigota crvenih i smeđih očiju mušica.

Abstract (english)

The aim of this study was to determine whether the white eye mutation in fruit flies Drosophila melanogaster is due to inheritance sex linked gene or it is autosomal mutation. We inoculate 5 males and 5 virgin females in special containers which we provide with recently prepaired base. After crossing the wild type flies (red eyes) and white flies through several generations we counted offsprings and confirm autosomal mutation as we realise 4 different colours of eye white, brown, red and scarlet. Red colour eyes are result of deposition two pigments xanthommatin (brown) and drosopterins (scarlet) in the pigment granules. W, st and bw genes encode ABC transporter protein that is responsible for transporting both pigments brown and scarlet. Mutation of both genes, st and bw, which encode defective protein causes white eyes due to ineffective transport of pigments in the pigment granules within the cell ommatidia. Null mutants of st have reduced capability to take up tryptophan and the result are scarlet eyes. Similarly, mutants with null allel at bw have reduced capability to take up guanine and the result are brown eyes. After counting the offspring of F2 generation the results weren´t similar to expected ratio 9:3:3:1. The reasons for mismatch with the ratio were possible errors in work such as replacement brown eye and scarlet eye flies, commpetition for food, blindness of white eye flies, using non-virgin flies and dependence on temperature of pigment production. Despite determination of mutation in this work we carried out crossing in which we got homozygotes of brown and scarlet flies.

• Keywords: spolno vezani geni; autosomalna mutacija; ABC protein; bw; st i w geni; omatidija
• Keywords (english): sex linked gene; autosomal muatition; ABC protein; bw; st and w genes; ommatidia
• Language: croatian
• URN:NBN: urn:nbn:hr:159:798207
• Study programme: Title: Biotechnology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-05-15 09:58:55