About the Spindle
During the process of chromosome division, a spindle-shaped structure with a wide center and narrow ends is formed, known as the spindle.
It consists of:
- Chromosomes
- Microtubules
- Kinetochore
What is the relationship between the spindle and the oocyte?
The spindle is like the “soul” of the egg, responsible for the alignment and division of chromosomes. If the spindle is abnormal, it may affect embryo development and even cause chromosomal abnormalities.。 However, the spindle cannot be seen from the outside of the egg and must be observed through a Spindle View imaging system.
What factors affect spindle integrity?
Internal factors:：
- Age: When a woman is over 40, the chance of spindle abnormalities increases.
- Oocyte maturation process: Even if the egg appears mature, observing the spindle’s location and visibility helps embryologists determine the optimal timing for fertilization.
External factors：
- Improper culture conditions (e.g., temperature, freezing process)
Top image: The spindle is located near the first polar body in typical cases.
Bottom image: The spindle is angled away from the first polar body.
Spindle view
Recommended for:：
- Advanced maternal age (≥ 40 years old)
- Low oocyte maturation rate
- Poor ovarian response
- Previous poor fertilization outcomes
- Fertilization with thawed eggs
Advantages of Spindle View:
- During ICSI (Intracytoplasmic Sperm Injection), it helps identify the optimal timing and angle for fertilization.
- Enables evaluation of egg quality based on spindle integrity.
Limitations of Spindle View:
- Requires highly experienced embryologists to operate.
How does spindle positioning technology precisely locate the spindle?
Spindle positioning technology uses a polarized light microscope to observe the spindle inside the egg. It utilizes the optical properties of the spindle to determine its location.
The polarized microscope provides a non-invasive and real-time way to visualize the spindle.
When combined with ICSI and other assisted reproductive techniques, it allows for more accurate targeting, improving the chance of successful fertilization and embryo development.
