British researchers have been denied permission to create controversial human–animal-derived hybrid embryos until doubts about the ethics and scientifi c value of the research are addressed. The Human Fertilisation and Embryology Authority said it was deferring a decision on whether to grant licences to teams from King's College London and Newcastle University until a wide-ranging consultation ...

Essential oils (EOs) are natural compounds used in various fields such as traditional medicine, gastronomy, and agriculture, often against plant animal parasites. In the present study, toxic pathological effects of basil (Ocimum basilicum) essential oil on development zebrafish embryos was investigated. The manufacturer datasheet reported linalool eugenol major compounds. were evaluated through...

In embryos of the glossiphoniid leech, Helobdella triserialis, as in many annelids, cytoplasmic reorganization prior to first cleavage generates distinct animal and vegetal domains of yolk-deficient cytoplasm, called teloplasm. Both domains are sequestered to the D' macromere, progenitor of the definitive segmental tissues, during the first three rounds of cell division. And it has been believe...

introduction: the contraception has been practiced for over 4000 years and the prevalence of contraceptive use has increased worldwide.the existing methods of contraception are not perfect and their acceptability is limited by side effects and inconvenience.thus there is a real need for new methods of contraception to be developed. the effects of the follicular fluid on the pregnancy rate has b...

The germ line is established in animal embryos with the formation of primordial germ cells (PGCs), which give rise to gametes. Therefore, the need to form PGCs can act as a developmental constraint by inhibiting the evolution of embryonic patterning mechanisms that compromise their development. Conversely, events that stabilize the PGCs may liberate these constraints. Two modes of germ cell det...