During Drosophila oogenesis, the endopolyploid nuclei of germ-line nurse cells undergo a dramatic shift in morphology as oogenesis progresses; the easily-visible chromosomes are initially polytenic during the early stages of oogenesis before they transiently condense into a distinct '5-blob' configuration, with subsequent dispersal into a diffuse state. Mutations in many genes, with diverse cel...

Vasa, a DEAD box mRNA helicase similar to eIF4A, is involved in pole plasm assembly in the Drosophila oocyte and appears to regulate translation of oskar and nanos mRNAs. However, several vasa alleles exhibit a wide range of early oogenesis phenotypes. Here we report a detailed analysis of Vasa function during early oogenesis using novel as well as previously identified hypomorphic vasa alleles...

RNA metabolism during amphibian oogenesis has been investigated by the analysis of individual cDNA cloned sequences. Two cDNA clone libraries were constructed from the pA+ RNA of Xenopus ovary and of tadpole. The accumulation of RNAs complementary to individual clones was examined during oogenesis by isolating RNA from oocytes of different stages. There are only two patterns of accumulation dur...

The level at which ornithine decarboxylase expression is regulated in growing oocytes has been investigated. Immunoprecipitation of the in vivo labelled proteins showed that ornithine decarboxylase accumulated less rapidly in stage IV oocytes than in previtellogenic stage I + II oocytes. Quantitative Northern analysis showed that ornithine decarboxylase mRNA is abundant in oocytes (about 8 x 10...

In 2004 and 2005, Johnson et al. published two very provocative studies (1, 2), in which they claimed that in the adult mouse ovary, neo-oogenesis takes place and originates either from the ovarian surface epithelium (OSE) (1) or from the bone marrow (BM) via circulating blood cells (2). These studies were provocative since they challenged the long-held view that mammals are born with a finite ...

We isolated and characterized a sequence coding for heat-shock protein 70 (HSP70) of the amphibian Pleurodeles waltl. Results from S1 nuclease protection assays led us to conclude that an hsp70 gene, strictly inducible in somatic cells during heat shock, is constitutively active during oogenesis. By quantitative northern and western blot analysis, we showed that both hsp70 mRNA and HSP70-relate...

cytoplasmic tail and prevents their internalization and degradation. Similarly to β-catenin, unbound p120ctn can translocate to the nucleus where it binds Kaiso, a zinc finger transcription factor that acts as a transcriptional repressor. Once bound to Kaiso, p120ctn relieves the repressor activity of Kaiso by dissociating it from its sequence-specific binding sites. As with β-catenin, Wnt sign...