Comparison Between Two Methodologies of Sample Preservation for RNA Extraction in Naturally Delivered Ovine Placenta

Area of Science:

• Reproductive Biology
• Animal Science
• Molecular Biology

Background:

• RNA extraction from ovine placenta typically involves invasive methods like surgery or euthanasia.
• The feasibility of obtaining high-quality RNA from naturally delivered ovine placentas is not well-established.
• Alternative methods are needed to align with the refinement principle in animal research.

Purpose of the Study:

• To evaluate the feasibility of extracting high-quality RNA from naturally delivered ovine placentas.
• To compare the efficacy of two preservation methods: snap freezing (SF) and RNAlater (LTR).
• To determine if placental delivery timing impacts RNA quality indicators.

Main Methods:

• Twenty-seven pregnant sheep were monitored until natural parturition.
• Placental tissues were collected immediately after delivery.
• Samples were preserved using either snap freezing or RNAlater treatment.
• RNA was extracted using a commercial kit, and concentration, A260/280 ratio, and RNA Quality Number (RQN) were measured.

Main Results:

• RNA concentration was significantly higher in RNAlater-preserved samples (70.39 ± 6.3 ng/µL) compared to snap-frozen samples (49.77 ± 10.5 ng/µL).
• The A260/280 ratio was significantly higher in snap-frozen samples (2.06 ± 0.01) versus RNAlater samples (2.03 ± 0.01).
• RNA Quality Number (RQN) was significantly higher in snap-frozen samples (6.81 ± 0.24) compared to RNAlater samples (2.84 ± 0.24), indicating superior RNA integrity.

Conclusions:

• High-quality RNA can be successfully extracted from naturally delivered ovine placentas.
• Snap freezing is a superior preservation method for maintaining RNA integrity (RQN) in ovine placental tissue.
• This method offers a viable, non-invasive alternative for placental RNA collection in sheep research, adhering to ethical guidelines.