Question

Arrange the following steps of embryo transfer technology, starting from first to last:
(A). Insemination
(B). Superovulation
(C). Transfer of embryo
(D). Flushing and grading
Choose the correct answer from the options given below:

• A. (A), (B), (D), (C).
• B. (B), (C), (D), (A).
• C. (C), (D), (A), (B).
• D. (B), (A), (D), (C).

Hint:

To remember the sequence of embryo transfer:
You must superovulate the donor first (B), then inseminate her (A).
After fertilization, flush out the embryos (D) and finally transfer them to the recipient (C).

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Embryo Transfer Technology (ETT) is an advanced reproductive technique used in livestock to amplify the reproductive rate of genetically superior females (donors).
The process involves harvesting embryos from a donor female and transferring them to synchronized recipient females.

Step 2: Detailed Explanation:
Let us arrange the technical steps of ETT in chronological order:
1. Superovulation (B): The donor female is treated with gonadotropins (like FSH) to stimulate the ovaries to release multiple ova during a single estrous cycle. This is the first step.
2. Insemination (A): The superovulated donor is bred or artificially inseminated using high-quality semen to fertilize the multiple released ova. This is the second step.
3. Flushing and Grading (D): Approximately 6 to 8 days post-insemination, the embryos are recovered non-surgically from the donor's uterus using a flushing medium.
The recovered embryos are evaluated under a microscope and graded based on their quality and developmental stage. This is the third step.
4. Transfer of Embryo (C): High-quality, viable embryos are transferred into synchronized recipient females, who serve as surrogate mothers to carry the pregnancies to term. This is the final step.
This sequence is represented by the order: (B) \(\rightarrow\) (A) \(\rightarrow\) (D) \(\rightarrow\) (C).

Step 3: Final Answer:
The correct chronological sequence is (B), (A), (D), (C). This corresponds to option (D).