trihybrid

Assuming independent assortment

In Drosophila the following wild type alleles are used for analysis v (vermilion eyes), cv (cross-veinless) and ct (cut or snipped wing edges). Flies doubly recessive and homozygous (v+v+,cvcv,ctct) are crossed with flies singly recessive and homozygous (vv, cv+cv+, ct+ct+). Female progeny that are vv+, cvcv+, ctct+ are then test crossed with the tripley recessive males (vv, cvcv, ctct)

P1=v+v+,cvcv,ctct x vv, cv+cv+, ct+ct+

F1 =Wild Type - V+V, cv+cv, ct+ct x vv, cvcv, ctct (gametes v, cv, ct)

F1 gamete types			exp	obs
v	cv⁺	ct⁺	181	580
v⁺	cv	ct	181	592
v	cv	ct⁺	181	45
v⁺	cv⁺	ct	181	40
v	cv	ct	181	89
v⁺	cv⁺	ct⁺	181	94
v	cv⁺	ct	181	3
v⁺	cv	ct⁺	181	5
				1448

Text iGenetics by Peter J. Russell

This web site is provided for instruction in Botany and Zoology 342

by Kenneth G. Wilson,
Professor of Botany
Miami University
wilsonkg@muohio.edu