GENERATIVE CELLS AND MALE GAMETES - ISOLATION, PHYSIOLOGY, AND BIOCHEMISTRY

This chapter focuses on the isolation procedures of generative cells and male gametes with an emphasis on the physiology and biochemistry of these isolated cells. In angiosperms the male gametes originate from the division of the generative cell, which occurs either in the pollen grain before anthesis or in the pollen tube after pollination. These cells are devoted to the transport of the genetic information of the male to the embryo sac for fertilization. The structural characteristics of generative cells and male gametes in situ are investigated by transmission electron microscopy (TEM), freeze fracture, and immunocytochemistry to observe the relationship among the different cells of the male gametophyte and the mechanism of their transmission in the pollen tube. In numerous species the two male gametes remain together in close association with the vegetative nucleus in the pollen grain, in the pollen tube, or both. This association, in which all the DNA of male heredity is contained, is termed the “male germ unit.” © 1992, Academic Press Inc.