Eggs from (C57B1 x A a G ^ mice were activated by treatment with hyaluronidase, which removed the follicle cells, and cultured in vitro. Observations were made 6-8 h after hyaluronidase treatment to determine the frequency of activation and the types of parthenogenones induced. Cumulus-free eggs resulting from hyaluronidase treatment were incubated for 2\ h in culture media of various osmolarit...

Parathormone (PTH) is composed of four glands embedded in the thyroid gland, but its function is mainly to keep calcium in the blood within normal range. It has got sensitive receptors that trigger the PTH to act in correcting serum calcium. As calcium is important for the normal functioning of many organs including vital organs like heart and brain, the PTH has to be prompt in maintaining calc...

Xenopus eggs are laid arrested at second metaphase of meiosis lacking a functional centrosome. Upon fertilization, the sperm provides the active centrosome that is required for cleavage to occur. The injection of purified centrosomes mimics fertilization and leads to tadpole formation (parthenogenesis). In this work we show that the parthenogenetic activity of centrosomes is inactivated by urea...

In flowering plants, haploid gametes – an egg cell and a sperm fuse to form the first diploid zygote. The zygote is progenitor stem that gives rise all embryonic post tissues organs. Unlike animals, both maternal paternal gene products participate in initial development of zygotes plants. Here, we discuss recent advances understanding zygotic transition embryo initiation angiosperms, including ...