A blastomere is one of the cells formed by the cleavage of a fertilized egg (zygote) during early embryonic development. These cells, produced by rapid cell division without significant growth, become progressively smaller with each division. Initially, they are totipotent, meaning each blastomere has the potential to develop into a complete embryo. However, as cleavage proceeds, their developmental potential typically becomes restricted, a process known as cell fate determination. The number and arrangement of blastomeres provide vital information for assessing the health and developmental potential of an embryo in various organisms, including humans. The structure and function of the blastomeres, from cell size to arrangement, is critical to the future development of the organism.
Blastomere meaning with examples
- During in vitro fertilization, embryologists carefully monitor the number and appearance of blastomeres to evaluate the embryo's quality and viability for implantation. A healthy embryo typically exhibits a consistent number of blastomeres within a specific timeframe post-fertilization.
- In frog embryos, the large blastomeres formed at the vegetal pole contain yolk, which influences the cleavage pattern and the distribution of developmental factors, impacting gastrulation and future tissue differentiation of the blastomeres.
- Scientists are studying the asymmetrical division of blastomeres in some species to understand how cell polarity is established and how these differences lead to differential gene expression, ultimately determining cell fates and specializations.
- After the initial cleavage divisions, compaction occurs, where blastomeres adhere tightly to each other, forming a morula. This reorganization of the blastomeres is crucial for proper cell-cell signaling and formation of the blastocyst.
- Genetic analysis of single blastomeres has been used to identify embryos carrying genetic disorders. This allows for preimplantation genetic diagnosis (PGD) so only embryos free of such disorders are selected for transfer.