Boule

Abstract: We have identified a localized RNA component of Xenopus germ plasm. This RNA, Xdazl (Xenopus DAZ-like), encodes a protein homologous to human DAZ (Deleted in Azoospermia), vertebrate DAZL and Drosophila Boule proteins. Human males deficient in DAZ have few or no sperm and boule mutant flies exhibit complete azoospermia and male sterility. Xdazl RNA was detected in the mitochondrial cloud and vegetal cortex of oocytes. In early embryos, the RNA was localized exclusively in the germ plasm. Consistent with other organisms, Xdazl RNA was also expressed in the spermatogonia and spermatocytes of frog testis. Proteins in the DAZ-family contain a conserved RNP domain implying an RNA-binding function. We have shown that Xdazl can function in vitro as an RNA-binding protein. To determine if the function of Xdazl in spermatogenesis was conserved, we introduced the Xdazl cDNA into boule flies. This resulted in rescue of the boule meiotic entry phenotype, including formation of spindles, phosphorylation of histone H3 and completion of meiotic cell division. Overall, these results suggest that Xdazl may be important for primordial germ cell specification in the early embryo and may play a role analogous to Boule in promoting meiotic cell division.

Abstract: A boule formed by high rate vapor phase growth of Group III-V nitride boules (ingots) on native nitride seeds (Figure 1), from which wafers may be derived for fabrication of microelectronic structures (Figure 5). The boule is of microelectronic device quality, e.g., having a transverse dimension greater than 1 centimeter, a length greater than 1 millimeter, and a top surface defect density of less than 107 defects cm-2. The Group III-V nitride boule may be formed by growing a Group III-V nitride material on a corresponding native Group III-V nitride seed crystal by vapor phase epitaxy at a growth rate above 20 micrometers per hour.

Abstract: The first section of the chapter is concerned with the membership of the boule - the conditions of appointment and service, the men who served in the boule, and the rewards and risks to which they were exposed. In particular the evidence is surveyed for the allocation to individual demes of specified numbers of seats in the boule, a system which seems in fact to have broken down in the second century B.C., though it continued to influence the layout of lists of bouleutae. The subdivision of the boule into tribal prytanies is next examined, and it is suggested that this may be the work of Ephialtes rather than a part of Cleisthenes' original organisation. In connection with the further subdivision of the prytanies so that some men should always be on duty, attention is given to a recently advanced theory that the prytanies split according to a regular scheme resembling but not identical with Cleisthenes' division of the tribes into trittyes: the evidence supports the adoption of such a convention by some tribes, but not a universally enforced rule. Little can be added to older discussions of the proedri, who took over the presidential duties of the prytanes in the fourth century, but their institution seems to be at any rate a little later than the democratic restoration of 403/2. The chapter ends with a study of the boule's meetings and meeting-places: the buildings occupied by the boule in the Agora are discussed, with special reference to the internal arrangements of the bouleuterium and the conditions in which members of the public were admitted during meetings; other places where the boule met are listed; procedure at meetings is examined; and the evidence for the position of the generals vis-a-vis the boule is reconsidered, with the suggestion that except at the time of the Peloponnesian War the generals did not in the classical period possess extra- ordinary privileges. [continued in text ...]

Abstract: Boule, a Drosophila orthologue of the vertebrate Dazl fertility factors, is a testis-specific regulator of meiotic entry and germline differentiation. Mutations inactivating either Boule, which is an RNA-binding protein, or Twine, which is a Cdc25-type phosphatase, block meiotic entry in males. Here we show that twine and boule interact genetically. We also find that protein expression from twine messenger RNA correlates with cytoplasmic accumulation of Boule and is markedly reduced by boule mutations. Remarkably, heterologous expression of Twine rescues the boule meiotic-entry defect, indicating that the essential function of Boule at the transition from G2 to M phase during meiosis is in the control of Twine translation.