Stem cell with primary focus on PGCs.pptx

Mainly related to Fishes

1. Content Introduction Characteristics of stem cells Types of stem cells Primordial germ cells Techniques and tools for visualization of PGCs Migration and transplantation of PGCs Surrogacy in fishes Applications of stem cells References

2. Introduction Stem cells are a class of undifferentiated cells having t he potential to differentiate into d ifferent types of cells in the body.

3. Characteristics of stem cells All stem cells regardless of their source have three general properties.

4. Types of stem cells (On the basis of potency) Totipotent e.g zygote Pluripotent e.g Embryonic cell Multipotent e.g Hematopoietic stem cell Oligopotent e.g Myleiod cell Unipotent e.g skin stem cell

5. (On the basis of source) Embryonic stem cells Germ line stem cells Mesenchymal stem cells Hematopoietic stem cells Neural stem cells Induced pluripotent cells

6. Primordial Germ cells S pecialized cells that play a crucial role in the development of reproductive systems . Sperms in males Eggs in females Precursors of gametes

7. Morphology of PGCs

8. Development PGCs are established in extraembryonic tissues at around 3 weeks after fertilization. Transcription factors microRNAs Signaling pairs Pluripotency factors Gene expression Signals from extracellular environment to inside of the cell Gene regulation Cell differentiation

9. Techniques and tools for PGC visualization Transgenic lines: The knowledge of these markers allowed the generation of different transgenic lines for PGC detection in vivo. Vasa Nanos Dnd-1 dazl Atlantic salmon Atlantic cod Turbot

10. Localized RNA expression (LRE): Synthesized mRNA Green fluorescent protein Fertilized egg Visualization of PGC

11. Markers and their significance Vasa sdf-1 dnd-1 Nanos 3a Germ cell development Survival and maintenance Prevents the formation of germ cell tumors Migration of PGC

12. Distribution of vasa-positive dots from the 2-cell to 8-cell stage (A,B) 2-cell, (C,D) 4-cell and (E,F) 8-cell stage embryos. (A, C, E) are lateral views, while (B, D, F) are animal pole views. A B C D E F

13. MIGRATION OF PGCS PGCs do not arise within the gonad, but rather arise elsewhere and migrate across the embryo to reach developing gonadal precursors. The chemo-attractants play an important role in the migration of PGCs Immature gonad

14. Isolation of PGCs Dissection Enzymatic digestion Fluorescence activated cell sorting Typically genital ridges Sort and isolate PGCs Dissociation of cells by trypsin

15. Transplantation methods

16. Surrogacy in fishes The first attempts to perform Germ Cell Transplantation (GCT) in fish were performed in Rainbow trout . Animals generated by transplantation of PGCs are called allogenics. Immature germ cells from a target species Related species Can produce sperm and eggs of target species Transplantation

17. Applications of stem cells Selective breeding and genetic improvement: Disease resistance and health management: Faster growth rate Improved feed conversion Therapies to treat diseases Introduce disease resistance traits

18. Sex reversal and sterility: Stem cells can be used to induce sex reversal in fish species where one sex is more desirable for aquaculture. By manipulating germline stem cells, it is possible to produce sterile fish.

19. Nutrition and growth enhancement: Environmental monitoring and toxicology: Bioengineered algae Enhance the growth and health Improve meat quality Used as Biosensors Detect environmental pollution Detect toxin

20. Work done on stem cells

21. References Yoshizaki G, Takeuchi Y, Kobayashi T, Takeuchi T. Primordial germa cell; a novel tool for fish bioengineering. Fish Physiol Biochem 2003; 28:453–457. Saito T, Psenicka M, Goto R, Adachi S, Inoue K, et al. (2014) The Origin and Migration of Primordial Germ Cells in Sturgeons. PLoS ONE 9(2): 1371. Yoshizaki G, Takeuchi Y, Sakatani S, Takeuchi T. Germ cell-specific expression of green fluorescent protein in transgenic rainbow trout under the control of the rainbow trout vasa-like gene promoter. Int J Dev Biol 2000; 44:323–326. Bhat, I. A., Dubiel , M. M., Rodriguez, E., & Jónsson , Z. O. (2023). Insights into Early Ontogenesis of Salmo salar : RNA Extraction, Housekeeping Gene Validation and Transcriptional Expression of Important Primordial Germ Cell and Sex-Determination Genes.  Animals ,  13 (6), 1094 . Köprunner , M., Thisse , C., Thisse , B., Raz , E., 2001. A zebrafish nanos -related gene is essential for the development of primordial germ cells. Genes Dev. 15, 2877–2885.