snRNP: Rich Nuclear Bodies in Hyacinthus orientalis L. Microspores and Developing Pollen Cells

Figure 2

Graph illustrating the average number of silver nitrate-stained extranucleolar bodies in the polarized microspores and differentiating pollen cells. In the microspore the average number of nuclear bodies was 2.2. During the whole course of pollen development the number of these structures was much higher in the vegetative nucleus that in the generative one. Until the separation of the generative cell from the sporoderm, the average number of agyrophylic nuclear bodies in the vegetative nucleus was the highest and reached values of over 2 per nucleus. During later stages of pollen development the average number of nuclear bodies in the vegetative nucleus successively decreased. In the generative nucleus silver nitrate-stained bodies were observed only in young pollen grains and their average number never reached over 0.5 per nucleus. In both nuclei of mature pollen grain no nuclear bodies were indicated. The values represent the average of three replicate experiments; the error bars indicate one standard error of the mean.