Contents

03 June 1994
Vol 264, Issue 5164

About The Cover

In certain fungi, the products of one meiosis remain encapsulated as a group, or tetrad, a feature that has allowed geneticists to study allele segregation, recombination, gene conversion, and other chromosomal properties. These studies are now possible in the higher plant Arabidopsis thaliana because of the discovery of the quartet mutations. Shown are pollen grains from plants with a quartet mutation, which, unlike wild-type pollen grains, are released in fused meiotic tetrads. See page 1458. [Photo: Daphne Preuss and Sung Y. Rheel