Veterinary Biochemistry- ICAR JRF/SRF 2024

• Chemical Cell Synchronization:
• Lovastatin: An inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase that depletes mevalonate. In cultured somatic cells, mevalonate starvation reversibly blocks cells in the $G_1$ phase of the cell cycle.
• (Nocodazole and Colchicine disrupt microtubules, arresting cells in M-phase).
• nalysis:
• (Lovastatin): Correct chemical for G1 synchronization.

Correct option: (3) Lovastatin.

• Generation of Transgenic Livestock and Rodents:
• Pronuclear DNA Microinjection (Gordon & Ruddle, 1980):
• Linearized recombinant transgene constructs are injected directly into the male pronucleus of freshly fertilized embryos at the One-Cell Stage (zygote).
• Performing microinjection at the single-cell stage prior to the first mitotic cleavage ensures that the integrated transgene is replicated and passed into every embryonic cell lineage, minimizing germline mosaicism.
• nalysis:
• (One-cell-stage): Correct developmental stage.

Correct option: (1) One-cell-stage.

• Cellular Reprogramming to Pluripotency:
• First pioneered by Shinya Yamanaka (2006, Yamanaka factors: Oct4, Sox2, Klf4, c-Myc) and James Thomson (2007):
• Differentiated adult somatic cells are reprogrammed into pluripotent stem cells (iPSCs) by the ectopic transfection of defined core transcription factor cocktails:

(The classic Thomson reprogramming gene cocktail).

• nalysis:
• (Pou5f1, Sox2, Nanog, Lin28): Correct factor combination.

Correct option: (1) PouSft, Sox2, Nanog, Lin28.