the capability to preserve human oocytes, blastocysts, ovarian tissue and spermatozoa is an important tool in human assisted reproductive techniques. this preservation allows patients undergoing chemotherapy or radiotherapy to preserve their fertility, and helps to attain all benefits from the costly ovarian superovulation therapies prior to art. the primary goal in establishing an appropriate ...

In the biflagellated alga Chlamydomonas, adhesion and fusion of the plasma membranes of gametes during fertilization occurs via an actin-filled, microvillus-like cell protrusion. Formation of this approximately 3-microm-long fusion organelle, the Chlamydomonas fertilization tubule, is induced in mating type plus (mt+) gametes during flagellar adhesion with mating type minus (mt-) gametes. Subse...

background: creation of artificial gametes may provide a universal solution for these patients of lacking gametes. stem cell technology may provide a way to obtain fully functional gametes. retinoic acid (ra) can initiate meiosis. several studies have demonstrated that ra can promote sperm cells differentiation from mouse embryonic stem cells (mescs) and other cells from human embryonic stem ce...

Sexual polyploidization, as a result of 2n gamete formation, is thought to be the main process involved in the origin of polyploid plants (Bretagnolle & Thompson, 1995). These gametes, possessing the somatic rather than the gametophytic chromosome number, can be formed either during microsporogenesis (2n pollen, big pollen, diplandroidy) or megasporogenesis (2n eggs, diplogynoecy). In general, ...

The segregation of compound-second chromosomes in males from two different stocks has been examined. Segregation is random in males from the C(2L)RM4, dp; C(2R)RM4, px stock. Gametes containing only one of the two compound chromosomes comprise 50% of the gametes, and gametes containing either both elements or neither element make up the other 50% of the gametes. In males from the C(2L)RM, b; C(...

During the mating reaction (fertilization) in the biflagellated alga, Chlamydomonas reinhardtii, mt+ and mt- gametes adhere to each other via their flagella and subsequently fuse to form quadriflagellated zygotes. In the studies reported here, we describe a monoclonal antibody directed against an mt+ flagellar surface molecule. The antibody blocks the adhesiveness of mt+ gametes, isolated mt+ f...

As the twenty-first century begins, changing technology is testing old rules of property law. In this Article, the author discusses the effect of modern technology on the Role Against Perpetuities. This discussion includes the arguments for and against recognition of the embryo as a life in being, as well as suggestions for legislative solutions to this issue.