"These cells co-develop together, just like they would in an actual embryo, and establish that history of being neighbors," ...

Scientists have found a way to study early embryonic development without real embryos. Using CRISPR, they programmed stem cells to self-organize into structures mimicking early embryos. The cells show ...

But the Trump administration’s recent guidance to “restore biological truth” on gender determination misses on both ...

In humans, embryonic cell compaction is a crucial step in the normal development of an embryo. Four days after fertilization, cells move closer together to give the embryo its initial shape.

Assuming that at least during the earliest phases of research, human embryos produced via in vitro fertilization (IVF) would be the best source for producing immortalized stem cell lines ...

In vitro fertilization (IVF). This fertility procedure helps couples and individuals conceive by combining a woman’s eggs with a man’s sperm in the lab. Research on HeLa cells paved the way ...

The pollen grain then germinates into a tube that guides the male reproductive cells to the depths of the ovary, picking up signals along the way that reveal the location of an ovule. Blocking signals ...

A Yale-led research team has uncovered how a naturally occurring biological mechanism found in mammals is able to prevent sperm cells from interacting with an egg, preventing fertilization.