Biology:Meiomitosis

From HandWiki

In cell biology, meiomitosis is an aberrant cellular division pathway that combines normal mitosis pathways with ectopically expressed meiotic machinery resulting in genomic instability.[1]

Description

Meiotic pathways are normally restricted to germ cells. Meiotic proteins drive double stranded DNA breaks, chiasma formation, sister chromatid adhesion and rearrange the spindle apparatus.[2]  

During meiosis, there are 2 sets of cell divisions, the second division is similar to mitosis in that sister chromatids are directly separated.  However, in the first meiotic division the sister chromatids are held together by cohesins and segregated from their homologous pair of cohesion bound sister chromatids after resolution of recombination crossover points (chiasma) between the homologous pairs.  The collision of mitosis and meiosis (first division) pathways could cause abnormal chiasma formation, abnormal cohesion expression, and mitotic/meiotic spindle defects that could result in insertions, deletions, abnormal segregation, DNA bridging, and potentially failure of cell division altogether resulting in polyploidy.

Role in cancer

Meiotic proteins have been noted to be expressed in cancer particularly melanoma[3] and lymphoma. In cutaneous T-cell lymphoma meiosis proteins have been shown to be regulated with the cell cycle.[4]  Lymphoma cell lines have also been noted to up-regulate meiosis specific genes with irradiation and a correlation with mitotic arrest and polyploidy has been noted.[5]  The overall role of meiomitosis in cancer development and evolution has yet to be determined.

Research

Meiomitosis in oogenesis from somatic cells has been demonstrated to generate semi-functional oocytes (egg cells) from human skin fibroblasts.[6] This technique was able to convert diploid somatic cells (with 46 chromosomes) into haploid gametes (with 23 chromosomes) without lengthy induced pluripotent stem cell (iPSC) reprogramming.[7] It combines somatic cell nuclear transfer (SCNT), with chemical and environmental cues to induce chromosome segregation.[8] The researchers removed the nucleus from a donor oocyte and replaced it with the nucleus from a somatic cell, preserving the oocyte's cytoplasm.[9] Next the somatic nucleus, is prompted to undergo meiomitosis, expelling one chromosome set into a polar body (meiotic phase), yielding a haploid oocyte.[6] This is achieved using kinase inhibitors and maturation media, bypassing full meiotic recombination.[10] In a 2025 proof-of-concept study by Oregon Health & Science University researchers, 82 functional oocytes were produced.[6] Fertilized with donor sperm via in vitro fertilization (IVF), 7 (9%) reached the blastocyst stage, forming embryos with diploid genetics.[6][11] The viable embryos showed balanced parental contributions.[6] However, this initial work featured low efficiency, chromosome errors, and ethical concerns such as embryo viability and designer babies.[12][13]

References

  1. ↑ Grichnik, James M. (October 2008). "Melanoma, nevogenesis, and stem cell biology". The Journal of Investigative Dermatology 128 (10): 2365–2380. doi:10.1038/jid.2008.166. ISSN 1523-1747. PMID 18787546. 
  2. ↑ Ross, Andrew L.; Leder, Daniel E.; Weiss, Jonathan; Izakovic, Jan; Grichnik, James M. (September 2011). "Genomic instability in cultured stem cells: associated risks and underlying mechanisms". Regenerative Medicine 6 (5): 653–662. doi:10.2217/rme.11.44. ISSN 1746-076X. PMID 21916599. 
  3. ↑ Lindsey, Scott F.; Byrnes, Diana M.; Eller, Mark S.; Rosa, Ashley M.; Dabas, Nitika; Escandon, Julia; Grichnik, James M. (2013). "Potential role of meiosis proteins in melanoma chromosomal instability". Journal of Skin Cancer 2013. doi:10.1155/2013/190109. ISSN 2090-2905. PMID 23840955. 
  4. ↑ Tsang, Matthew; Gantchev, Jennifer; Netchiporouk, Elena; Moreau, Linda; Ghazawi, Feras M.; Glassman, Steven; Sasseville, Denis; Litvinov, Ivan V. (2018-12-28). "A study of meiomitosis and novel pathways of genomic instability in cutaneous T-cell lymphomas (CTCL)". Oncotarget 9 (102): 37647–37661. doi:10.18632/oncotarget.26479. ISSN 1949-2553. PMID 30701021. 
  5. ↑ Kalejs, Martins; Ivanov, Andrey; Plakhins, Gregory; Cragg, Mark S.; Emzinsh, Dzintars; Illidge, Timothy M.; Erenpreisa, Jekaterina (2006-01-09). "Upregulation of meiosis-specific genes in lymphoma cell lines following genotoxic insult and induction of mitotic catastrophe". BMC Cancer 6: 6. doi:10.1186/1471-2407-6-6. ISSN 1471-2407. PMID 16401344. 
  6. ↑ 6.0 6.1 6.2 6.3 6.4 Marti Gutierrez, Nuria; Mikhalchenko, Aleksei; Shishimorova, Maria; Frana, Daniel; Van Dyken, Crystal; Li, Ying; Ma, Hong; Koski, Amy et al. (2025-09-30). "Induction of experimental cell division to generate cells with reduced chromosome ploidy" (in en). Nature Communications 16 (1): 8340. doi:10.1038/s41467-025-63454-7. ISSN 2041-1723. PMC 12485136. https://www.nature.com/articles/s41467-025-63454-7. 
  7. ↑ Sample, Ian (2025-09-30). "Human skin cells are turned into eggs in fertility breakthrough". The Guardian. https://www.theguardian.com/science/2025/sep/30/human-skin-cells-turned-into-eggs-fertility-breakthrough. 
  8. ↑ "Scientists create human eggs using skin cells". Reuters. 2025-09-30. https://www.reuters.com/business/healthcare-pharmaceuticals/scientists-create-human-eggs-using-skin-cells-2025-09-30/. 
  9. ↑ "OHSU researchers develop functional eggs from human skin cells". 2025-09-30. https://news.ohsu.edu/2025/09/30/ohsu-researchers-develop-functional-eggs-from-human-skin-cells. 
  10. ↑ "Scientists made human egg cells from skin cells". Science News. 2025-09-30. https://www.sciencenews.org/article/human-egg-cells-from-skin-cells. 
  11. ↑ "Working Egg Cells Made Using DNA From Human Skin in World First". ScienceAlert. 2025-09-30. https://www.sciencealert.com/working-egg-cells-made-using-dna-from-human-skin-in-world-first. 
  12. ↑ Howard, Jacqueline (2025-09-30). "Scientists use human skin cells to create functional eggs". CNN. https://www.cnn.com/2025/09/30/science/human-skin-cells-egg-infertility. 
  13. ↑ "Scientists Made Human Eggs From Skin Cells and Used Them to Form Embryos". Wired. 2025-09-30. https://www.wired.com/story/scientists-made-human-eggs-from-skin-cells-and-used-them-to-make-embryos/. 

Sources




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