dMAN1 is detectable in the nuclear envelope of embryonic cells including the pole cells.
The remainder of the male reproductive system is derived from embryonic mesoderm, except for the germ cells, or spermatogonia, which descend from the primordial pole cells very early during embryogenesis.
From these results I thus conclude that Tud protein remains largely uncleaved before pole cells form.
Phase III was defined as beginning at the initial dorsal movement of the pole cells which occurs early in embryogenesis.
Among these genes are oskar, vasa (vas), tudor (tud), and valois (vls) which are essential for the formation of pole cells, the germline progenitors [4].
As an initial step to elucidate the biochemical activity of Tud I asked whether a limited region of the molecule would support the formation of pole cells.
In early Drosophila embryos, the germ plasm is localized to the posterior pole region and is partitioned into the germline progenitors, known as pole cells.
Among these genes are oskar (osk), vasa (vas), tudor (tud), and valois (vls) which are essential for the formation of pole cells, the germline progenitors [3].
The different GFP-Tud transgenes were introduced into a tud1 background and the formation of pole cells in eggs laid by transgenic tud1 females was analyzed.
MtrRNA injected into the UV-irradiated Drosophila zygote restored the formation of pole cells [14] indicating that this class of RNA may be essential for pre-patterning of the germ plasm in Drosophila, sea urchin [15] and Xenopus [16] zygote.
From the five tested transgenic lines, only the largest C-terminal Tud-3ZS+L construct was found to be able to restore the formation of pole cells (Fig. 4D).
