Isolation of two populations of sperm cells from the pollen tube of Torenia fournieri

Abstract

The two sperm cells of Torenia fournieri are dimorphic. The dimorphic character suggests that they might be preferentially involved in fertilization during in vivo fusion with the egg cell and central cell. To probe the mechanism of preferential fertilization, it is necessary to use the most current molecular techniques. For this purpose, populations of >1000 individuals of the two dimorphic sperm cells, Sua (unassociated with the vegetative nucleus) and Svn (associated with the vegetative nucleus) were isolated from pollen tubes that had grown out of the cut ends of the styles. The two sperm cells released from pollen tubes remained attached to one another. When the two attached sperm cells were transferred into a solution containing 0.01% cellulose, 0.01% pectinase, and 5% mannitol, the connection between the two cells disappeared, and they were easily separated using a micromanipulator. The collection of these two individual populations containing over a thousand cells will permit research on gametic recognition at the molecular level.

Detection of changes in the nuclear phase and evaluation of male germ units by flow cytometry during in vitro pollen tube growth in Alstroemeria aurea

“…Sperm dimorphism, which showed difference of sperm cells in size, shape, and organelle content, is also observed in the pollen tube (Russell 1991;Tian et al 2001;Chen et al 2006). …”

Sperm dimorphism in terms of nuclear shape and microtubule accumulation in Cyrtanthus mackenii

“…Immediately after the formation of sperm cells in pollen tubes cultured for 12 h, the Sua nuclei were found to be significantly longer than the Svn nuclei ( Table 2). The difference in nuclear length between Svn and Sua increased with extended culture time from 12 to 24 h. The patterns of dimorphism in sperm cells in the MGUs, in terms of cell shape, have been reported to vary among species: the volume and surface area of Svn are greater than those of Sua in P. zeylanica (Russell 1984) and Torenia fournieri (Chen et al 2006), while the volume of the Sua is greater than that of Svn in N. tabacum (Tian et al 2001). Moreover, in the case of N. tabacum, dimorphism arises late during sperm development (Tian et al 2001), whereas in Plumbago zeylanica, it progressively advanced during development (Russell and Strout 2005).…”

What we have learned from transcript profile analyses of male and female gametes in flowering plants

“…The dimorphic nature of the sperm cell in Plumbago zeylanica was reported by Russell [29]. Researchers have now successfully applied this technique to collect dimorphic sperm cells individually from P. zeylanica [23], N. tabacum [24], and Torenia fournieri [25], based upon known size differences.…”

“…Nicotiana tabacum [25] Semi-in vivo pollen tube Torenia fournieri [26] a) Including R. arborium, R. konori, R. macgregoriae, and R. nuttallii.…”