A mouse with two dads — and a new frontier for biology | Katsuhiko Hayashi

2024/11/18

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Katsuhiko Hayashi

Katsuhiko Hayashi: 本演讲主要介绍了体外配子发生技术(IVG)的最新进展及其应用前景。该技术能够在体外利用多能干细胞培育出成熟的卵子和精子，突破了传统辅助生殖技术的局限性。演讲者详细阐述了IVG技术的原理、过程以及在小鼠模型上的成功应用，包括利用雄性小鼠细胞培育出卵子并成功繁殖后代。此外，演讲者还提到了IVG技术在保护濒危物种和解决人类生殖问题上的潜在应用，例如，利用该技术保护仅剩两只雌性的北方白犀牛。然而，该技术也引发了伦理方面的讨论，例如同性生殖的可能性以及对人类生殖方式的潜在影响。演讲者强调了IVG技术在动物实验上的成功，并暗示了其未来在人类生殖领域的应用潜力，但同时也暗示了这项技术所带来的伦理挑战。 Katsuhiko Hayashi: 演讲中，Hayashi 详细解释了体外配子发生技术（IVG）的科学原理，以及该技术如何通过模拟体内生殖细胞的形成过程，在体外利用多能干细胞（包括诱导多能干细胞）生成成熟的卵子和精子。他重点介绍了其团队在小鼠模型上取得的突破性进展，成功地利用小鼠多能干细胞培育出能够受精并产下健康后代的卵子，以及通过操纵染色体，利用雄性小鼠细胞培育出卵子并繁殖后代。Hayashi 还强调了 IVG 技术的广泛应用前景，包括在保护濒危物种（如北方白犀牛）方面的应用，以及为同性伴侣提供生育机会。演讲的最后，Hayashi 既表达了对 IVG 技术未来应用的乐观展望，也谨慎地提及了这项技术可能带来的伦理和社会问题，呼吁人们对这项技术进行深入的伦理讨论和规范。

Deep Dive

Key Insights

Why is the germ cell lineage important in biology?

Germ cells are the only immortal cells in the body, ensuring the perpetuity of life through generations. They are crucial for reproduction and maintaining biodiversity.

What challenges do current reproductive technologies face?

Current assisted reproductive technology requires sperm and egg to be obtained from the body. If these are not available, there are no options for reproduction.

How does in vitro gametogenesis (IVG) work?

IVG uses pluripotent stem cells, which can differentiate into any cell type, to create germ cells (sperm or eggs) outside the body. This process mimics natural development signals.

What are the potential applications of IVG beyond human reproduction?

IVG can help preserve endangered species by creating germ cells from easily collectable cells like skin cells. It can also aid in livestock reproduction to prevent economic losses.

How can IVG contribute to the preservation of endangered species like the northern white rhinoceros?

Researchers are using IVG to generate egg precursors from northern white rhinoceros pluripotent stem cells, aiming to create a mini-ovary system to mature these precursors into viable eggs.

What is the significance of the ability to switch sex chromosomes in IVG?

By switching sex chromosomes, IVG can bypass sex-dependent reproduction, allowing the creation of germ cells from two fathers or two mothers, expanding reproductive possibilities.

How did researchers create mice from two fathers using IVG?

Researchers converted male skin cells into induced pluripotent stem cells (iPSCs) with XY chromosomes, then selected rare iPSCs with XX chromosomes to create eggs. These eggs were fertilized to produce healthy mice.

What future possibilities does IVG open up for human and animal reproduction?

IVG could enable reproduction from two fathers, two mothers, or other combinations, potentially revolutionizing assisted reproductive technologies and conservation efforts.

Chapters

Biologist Katsuhiko Hayashi discusses the science of in vitro gametogenesis (IVG), an experimental technique for creating lab-made sperm or eggs from any type of cell, and explores its implications for human reproduction and biodiversity preservation.

IVG involves replicating the germ cell formation process outside the body using pluripotent stem cells.
Mature eggs and sperm can be generated from mouse pluripotent stem cells, capable of fertilization and producing healthy offspring.
This technology could be applied to various mammalian species, including humans, livestock, and endangered animals.

Shownotes Transcript

You're familiar with the story: a sperm and an egg meet to create an embryo, which has the potential to give rise to new life. But what if you could create a sperm or egg from any cell, even a single skin cell? Biologist Katsuhiko Hayashi discusses the science of in vitro gametogenesis (IVG) — an experimental technique for creating lab-made sperm or eggs out of just about any type of cell — and explores its implications for endangered species, human reproduction and more.

A mouse with two dads — and a new frontier for biology | Katsuhiko Hayashi 09:29 Share