SPERMATOGENESİS AND DYNAMİC STEM CELLS

Abstract

Stem cell shave a tremendous therapeutic potential with their ability to continually renew themselves and their ability to transform into almost all mature cells in our body. In the male reproductive system, a dynamic group of stem cells proliferates and prevents in fertility. This process is called spermatogenesis in mammals and the testis occurs in seminiferous tubules. Testicular stem cells, called germ stem cells (GKH) are capable of rapid regeneration after self-renewal and injury during adult life. How did spermatocytes occur dynamically in the later stages of old age? which is an indispensable element of the male reproductive system and is necessary for the continuation of the next generation. There has always been a question I asked and the answer was sought. In our review study, the changes of spermatogonium proliferating with mitosis in seminiferous tubules up to spermatozoa with meiosis and stem cell reserves are discussed.

Keywords

• Germ stem cells,Spermatogonium,Spermatogenesis.

SPERMATOGENEZİS VE DİNAMİK KÖK HÜCRELER

Öz

Kök hücreler kendilerini sürekli yenileyebilme yetenekleri ve vücudumuzda bulunan hemen tüm erişkin hücrelere dönüşebilme yetenekleri ile muazzam bir terapötik potansiyele sahiptirler. Erkek üreme sisteminde dinamik bir kök hücre grubu sürekli çoğalarak infertilite oluşumunu engellemektedir. Bu süreç memelilerde spermatogenezis olarak adlandırılır ve testis seminifer tübüllerinde gerçekleşir. Germ kök hücreleri (GKH) olarak adlandırılan testis kök hücreleri, erişkinlik hayatı boyunca kendini yenileme ve hasarlanma sonrası hızlı rejenerasyon yeteneğine sahiptirler. Erkek üreme sisteminin vazgeçilmez unsuru olan ve bir sonraki neslin devamı için gerekli olan süreçte spermatogenezin dinamik bir şekilde yaşlılığın ilerleyen dönemine kadar nasıl gerçekleştiği? Her zaman sorulan ve yanıtı aranan soru olmuştur. Derleme çalışmamızda seminifer tübüllerde mitozla çoğalan spermatogonyumların mayozla spermatid oluncaya kadar ki değişimleri ve kök hücre rezervleri ele alınmıştır.

Anahtar Kelimeler

• Germ kök hücreleri,Sprematogonyum,Spermatogenezis

References

1. Aloisio, G.M, Nakada, Y., Saatcioglu, H.D., Peña, C.G., Baker, M.D., Tarnawa ED, Mukherjee, J., Manjunath, H., Bugde, A., Sengupta, A.L., et al., 2014, PAX7 expression defines germ line stem cells in the adult testis, J Clin. Invest., 124, 3929-3944.
2. Amoyel, M., Simons, B.D., and Bach, E.A., 2014, Neutral competition of stem cells is skewed by proliferative changes downstream of Hh and Hpo, EMBO J, 33, 2295-2313.
3. Can, A., 2014, Kök Hücre: biyolojisi, türleri ve tedavide kullanımları, Akademisyen Tıp Kitabevleri, Ankara.
4. Chalancon, G., Ravarani, C.N.J., Balaji, S., Martinez-Arias, A., Aravind, L., Jothi, R. and Babu, M.M., 2012, Inter play between gene expression noise and egulatory network architecture, TrendsGenet., 28, 221-232.
5. de Rooij, D.G. and Russell, L.D., 2000, All you wanted to know about spermatogonia but were afraid to ask. J. Androl., 21, 776-798.
6. Fuchs, E. and Chen, T., 2013, A matter of life anddeath: self-renewal in stem cells. EMBO Rep., 14, 39-48.
7. Hara, K., Nakagawa, T., Enomoto, H., Suzuki, M., Yamamoto, M., Simons, B. D. and Yoshida, S., 2014, Mouse spermatogenic stem cells continually interconvert between equipotent singly isolated and syncytial states. Cell Stem Cell, 14, 658-672.
8. Huckins, C., 1971 The spermatogonial stem cell population in adult rats, I. Their morphology, proliferation and maturation. Anat. Rec., 169, 533-557.

9. Imayoshi, I., Isomura, A., Harima, Y., Kawaguchi, K., Kori, H., Miyachi, H., Fujiwara, T., Ishidate, F., and Kageyama, R., 2013, Oscillatory control of factors determining multipotency and fate in mouse neural progenitors. Science, 342, 1203-1208.
10. Klein, A.M., and Simons, B.D., 2011, Universal patterns of stem cell fate in cycling adult tissues. Development, 138, 3103-3111.
11. Komai, Y., Tanaka, T., Tokuyama, Y., Yanai, H., Ohe, S., Omachi, T., Atsumi, N., Yoshida, N., Kumano, K., Hisha, H., et al., 2014, Bmi1 expression in long-term germ stem cells. Sci. Rep., 4, 6175.
12. Krieger, T., and Simons, B.D., 2015, Dynamic stem cell heterogeneity, Development, 142, 1396-1406.
13. Martin-Rendon, E., Watt, S.M., 2003, Stem cell plasticity. Br J Haematol., 122, 877-91.
14. Matur, İ., Solmaz, S., 2011, Kök Hücre Üretiminde Güncel Yaklaşımlar. Arşiv, 168-186.
15. Nakagawa, T., Sharma, M., Nabeshima, Y., Braun, R.E., and Yoshida, S., 2010, Functional hierarchy and reversibility with in the murine spermatogenic stem cell compartment, Science, 328, 62-67.
16. Ritsma, L., Steller, E.J.A., Ellenbroek, S.I.J., Kranenburg, O., Borel Rinkes, I.H.M., and vanRheenen, J., 2013, Surgical implantation of an abdominal imaging window for intravital microscopy. Nat. Protoc., 8, 583-594.
17. Shinohara, T., Orwig, K.E., Avarbock, M.R., and Brinster, R.L., 2000, Spermatogonial stem cell enrichment by multi parameter selection of mouse testis cells, Proc. Natl. Acad. Sci., 97, 8346-8351.
18. Simons, B.D., and Clevers, H., 2011. Strategies for homeostatic stem cell self renewal in adult tissues. Cell, 145:851-862.
19. Treutlein, B., Brownfield, D.G., Wu, A.R., Neff, N.F., Mantalas, G.L., Espinoza, F.H., Desai, T.J., Krasnow, M.A., and Quake, S.R., 2014, Reconstructing lineage hierarchies of the distal lung epithelium using single-cell RNA-seq, Nature, 509, 371-375.
20. TUBA, 2004, Kök hücre araştırmalarında güncel kavramlar, Türkiye Bilimler Akademisi Raporları, Ankara, 7.
21. Ullah, I., Subbarao, R.B., Rho, G.J., 2015, Human mesenchymal stem cells - current trends and future prospective, Biosci Rep., 35(2). pii: e00191. doi:10.1042/BSR20150025.
22. Weissman, I.L., 2000, Stem cells: units of development, units of regeneration, and units in evolution, Cell, 100, 157-168.