In enucleation of a mature, unfertilized ovum for cloning or experimental manipulations, which methods can be used to remove or inactivate the nuclear material?

Introduction / Context:
Removal or inactivation of the oocyte nucleus (enucleation) is a key step in somatic cell nuclear transfer and certain developmental biology experiments. The method chosen must eliminate maternal nuclear DNA while preserving cytoplasmic integrity for subsequent reprogramming.

Given Data / Assumptions:

• Target cell is a mature unfertilized ovum (metaphase II).
• Goal is to remove or inactivate the maternal nucleus (germinal vesicle or metaphase plate).
• Oocyte viability postprocedure is essential.

Concept / Approach:
Two classic approaches are used: (1) microsurgical removal of the nucleus using fine glass needles under a microscope; (2) ultraviolet irradiation to inactivate nuclear DNA while preserving cytoplasm. Choice depends on species, equipment, and downstream application.

Step-by-Step Solution:

Verification / Alternative check:
Published SCNT protocols across mammals (e.g., bovine, ovine) and amphibians (Xenopus) describe both strategies, confirming applicability.

Why Other Options Are Wrong:

• Neutralization/homogenization destroys cellular architecture.
• Antibody-mediated nuclear digestion is not a standard, practical enucleation method.

Common Pitfalls:
Overexposure to UV damaging cytoplasm; mechanical trauma during microsurgery reducing developmental competence.

Final Answer:
Both irradiation and microsurgical removal can be used