In some species such as flies, worms, frogs and fish, the key to forming and maintaining early germ cell populations is the assembly of germ plasm, microscopically distinct egg cytoplasm that is rich in RNAs, RNA-binding proteins and ribosomes. Cells which inherit germ plasm are destined for the germ cell lineage. In contrast, in mammals, germ cells are formed and maintained later in developmen...

A 81-year-old man had multiple skin lesions (brown-red plaques on the face, abdomen, and back) and asthenia. There was no hepatosplenomegaly or adenopathy. Despite normal blood count values, the peripheral smear contained blasts (7%). Bone marrow examination showed 50% of blasts and mild erythroid dysplasia. The abnormal cells were medium-sized with blastic round (panels A-B) or convoluted (pan...

Blastic plasmacytoid dendritic cell neoplasm is a rare and aggressive hematodermic neoplasia with frequent cutaneous involvement and leukemic dissemination. We report the case of a 76-year-old man with a 2 month history of violaceous nodules and a tumor with stony consistency, located on the head, and mandibular, cervical and supraclavicular lymphadenopathies. Multiple thoracic and abdominal ad...

Segregation of the germ line from the soma is an essential event for transmission of genetic information across generations in all sexually reproducing animals. Although some well-studied systems such as Drosophila and Xenopus usematernally inherited germ determinants to specify germ cells, most animals, including mice, appear to utilize zygotic inductive cell signals to specify germ cells duri...

In Drosophila melanogaster, primordial germ cells are specified at the posterior pole of the very early embryo. This process is regulated by the posterior localized germ plasm that contains a large number of RNAs of maternal origin. Transcription in the primordial germ cells is actively down-regulated until germ cell fate is established. Bulk expression of the zygotic genes commences concomitan...

Ovarian and paraovarian neoplasms are uncommon in children, mainly originating from germ cell tumors and, least frequently, epithelial tumors. There is an association between genital tract tumors and Proteus syndrome, a rare, sporadic, and progressive entity, characterized by a postnatal overgrowth in several tissues caused by a mosaic mutation in the AKT1 gene. We describe a 20-month-old asymp...