HUMAN
EMBRYO - SCI & TECH
News: Lab-grown human ‘embryo’ created
without eggs or sperm
What's
in the news?
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Scientists have developed human embryo-like structures without using
sperm, an egg or fertilisation, offering hope for research on miscarriage
and birth defects but also raising fresh ethical concerns.
Key
takeaways:
●
Earlier this year, several labs around the
world released preprint studies that had not been peer-reviewed, describing
their development of early human embryo-like structures.
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This achievement was made possible through
the use of stem cells, which are
undifferentiated cells capable of transforming into various cell types in the
body.
Synthetic
Embryos:
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Synthetic embryos are embryos, which are created without fertilization.
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Such embryos (also known as artificial
embryos) do not require an egg or sperm cell to facilitate their creation.
Instead, these embryos rely on self-assembling stem cell structures to mimic the
natural process of early human development.
Creating
Synthetic Human Embryo:
●
By manipulating the culture conditions and
the signals that guide cell differentiation,
researchers can coax stem cells to self-organize into three-dimensional
structures that mimic some aspects of early embryonic development.
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For example, these structures can form a
blastocyst-like cavity, a placenta-like tissue, and a primitive streak-like
structure, which marks the beginning of gastrulation, the process by which the
three germ layers (ectoderm, mesoderm, and endoderm) are formed.
Embryonic
Development Timeline:
Fertilization:
●
Occurs when a sperm cell penetrates and
fertilizes an egg cell, forming a zygote.
Cleavage:
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The zygote undergoes multiple rounds of
cell division, producing a ball of cells called a morula.
Blastocyst
Formation:
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The morula continues to divide and
eventually forms a blastocyst, consisting of an inner cell mass (which becomes
the embryo) and an outer layer (which becomes the placenta).
Implantation:
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The blastocyst attaches to the uterine
wall and begins to grow.
Gastrulation:
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The embryo undergoes a process called
gastrulation, during which it forms three primary germ layers: ectoderm,
mesoderm, and endoderm.
Organogenesis:
●
The germ layers differentiate into
specific cell types, leading to the formation of organs and tissues.