Current scenario and challenges ahead in application of spermatogonial stem cell technology in livestock

• Published in: Journal of assisted reproduction and genetics Vol. 38; no. 12; pp. 3155 - 3173
• Main Authors: Binsila, Balakrishnan, Selvaraju, Sellappan, Ranjithkumaran, Rajan, Archana, Santhanahalli Siddalingappa, Krishnappa, Balaganur, Ghosh, Subrata Kumar, Kumar, Harendra, Subbarao, Raghavendra B., Arangasamy, Arunachalam, Bhatta, Raghavendra
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-12-2021; Springer Nature B.V
• Subjects: Cell culture; Cell differentiation; Cryopreservation; Epigenetics; Fertility; Gamete Biology; Genome editing; Germplasm; Growth factors; Gynecology; Human Genetics; Livestock; Medicine; Medicine & Public Health; Molecular modelling; Propagation; Reproductive Medicine; Spermatogenesis; Stem cell transplantation; Stem cells; Spermatogonial stem cell; Isolation; Livestock; Culture system; Cryopreservation; Growth factors
• ISSN: 1058-0468; 1573-7330
• DOI: 10.1007/s10815-021-02334-7

Purpose
Spermatogonial stem cells (SSCs) are the source for the mature male gamete. SSC technology in humans is mainly focusing on preserving fertility in cancer patients. Whereas in livestock, it is used for mining the factors associated with male fertility. The review discusses the present status of SSC biology, methodologies developed for in vitro culture, and challenges ahead in establishing SSC technology for the propagation of superior germplasm with special reference to livestock.
Method
Published literatures from PubMed and Google Scholar on topics of SSCs isolation, purification, characterization, short and long-term culture of SSCs, stemness maintenance, epigenetic modifications of SSCs, growth factors, and SSC cryopreservation and transplantation were used for the study.
Result
The fine-tuning of SSC isolation and culture conditions with special reference to feeder cells, growth factors, and additives need to be refined for livestock. An insight into the molecular mechanisms involved in maintaining stemness and proliferation of SSCs could facilitate the dissemination of superior germplasm through transplantation and transgenesis. The epigenetic influence on the composition and expression of the biomolecules during in vitro differentiation of cultured cells is essential for sustaining fertility. The development of surrogate males through gene-editing will be historic achievement for the foothold of the SSCs technology.
Conclusion
Detailed studies on the species-specific factors regulating the stemness and differentiation of the SSCs are required for the development of a long-term culture system and in vitro spermatogenesis in livestock. Epigenetic changes in the SSCs during in vitro culture have to be elucidated for the successful application of SSCs for improving the productivity of the animals.
Graphical abstract