Orphan mice are created in the lab using only unfertilized mouse eggs, a huge step towards having single-parent babies.
- Orphan mice were created in the lab from unfertilized mouse eggs.
- Recent scientific advances mark a huge step towards having children with one parent.
- The approach has not been successful in mammals mainly due to genomic imprinting.
- In this process, the original parent determines which copy of the gene is active.
Orphan mice have been created in the lab using only unfertilized mouse eggs, which could one day pave the way for single-parent babies.
Virgin birth, also known as parthenogenesis, has previously been observed naturally in birds, lizards, snakes, sharks, rays, and other fish.
But now scientists China they are said to have achieved parthenogenesis in mice without any male genetic DNA.
Previous attempts in mammals have largely been unsuccessful due to genomic imprinting, a process in which the parent of origin determines which copy of a gene is active.
Orphan mice have been created in the lab using only unfertilized mouse eggs, which could one day pave the way for single-parent babies.
HOW IS DIRECT GENERATION POSSIBLE?
Virgin birth is also called parthenogenesis.
Parthenogenesis is fatherless reproduction in animals that usually require two parents to produce offspring.
This is a natural form of asexual reproduction in which the growth and development of embryos occurs without fertilization by sperm.
In animals, parthenogenesis means the development of an embryo from an unfertilized egg.
This process has been observed in honey bees, ants and birds.
In plants, parthenogenesis is an integral process of apomixis.
Yangchang Wei and colleagues at Shanghai Jiao Tong University have shown that parthenogenesis is possible in mammals using a targeted technique that edits DNA methylation marks, which are chemical modifications that can change gene activity without changing the underlying DNA sequence.
The authors applied an epigenetic rewriting approach to seven imprinting control regions in mouse oocytes, successfully modifying DNA methylation in one copy of the gene but not in the other.
According to the researchers, the transfer of the modified embryos into foster female mice resulted in viable full-term offspring.
“After parthenogenetic activation, these edited regions showed retention of methylation as naturally established regions during early preimplantation development,” they wrote in their paper.
“The transfer of modified parthenogenetic embryos to adoptive mothers led to a significant lengthening of development and, finally, to obtaining viable full-term offspring.
“These data demonstrate that parthenogenesis can be achieved by targeted epigenetic rewriting of several critical regions of imprinting control.”
However, only one living offspring survived to adulthood, highlighting the need for more research and refinement of the method used to increase its success rate.
However, the results show that parthenogenesis in mammals can be achieved through DNA chemical changes used by scientists.
Parthenogenesis is a process that essentially forms “clones” of the parent, since the embryo receives genetic material from only one individual. Pictured are orphan mouse embryos.
According to the authors, the possibility of parthenogenesis in mammals opens up possible avenues in agriculture, research, and medicine.
Parthenogenesis is a process that essentially forms “clones” of the parent, since the embryo receives genetic material from only one individual.
One of the most typical processes for this form of reproduction is the fertilization of an egg by an immature egg that behaves almost like a sperm cell.
Usually, parthenogenesis occurs in lower plants and invertebrates such as ants, wasps, or bees.
However, it has also been seen in some species such as reptiles, fish, and even birds that normally reproduce sexually.
Latest study published in the journal Proceedings of the National Academy of Sciences.
HOW DOES CLONING OCCUR IN NATURE?
Asexual reproduction—when an organism reproduces without fertilization—requires only one parent, as opposed to sexual reproduction, which requires two parents.
Since there is only one parent, the secondary cells (sperms and eggs) do not fuse and there is no genetic mixing.
Because of this, the offspring of organisms that reproduce asexually are genetically identical to the parent and to each other – these are clones.
For example, a female marble crayfish can cause her eggs to start dividing into embryos.
Normal germ cells contain one copy of each chromosome. But mutant cancers have two germ cells.
Two germ cells fuse and produce a female cancer embryo with three copies of each chromosome instead of the usual two.
Some other examples of organisms that can clone themselves include:
- hammerhead sharks
- cockroaches
- aphid
- Jellyfish
- Marmocrebs (marble shrines)
- Whiptailed Desert Grassland Lizards
- gall wasps
- Komodo dragons