CryoStore diary - Firouzeh Sadeghzadeh

July 2024 - January 2025 | SYSAAF, France

Exploring the World of PGCs: Achievements and Future Directions in the restoration of the complete genetic heritage of a poultry breed

I started my PhD in July 2024 and I spent 3 months (September until the end of November) at INRAE as my first secondment. Throughout the course of my research journey, I have acquired a deep understanding of the fascinating field of primordial germ cell (PGC) biology, with an emphasis on their collection, cultivation, manipulation, and injection into chicken embryos. This work is pivotal for the restoration of the complete genetic heritage of a poultry breed. Let me walk you through the skills I have honed, the experiments I have been part of and the exciting next steps in our research.

Achievements and Skills Acquired

Over the course of my research, I have developed and refined several laboratory skills that have been crucial in conducting experiments involving PGCs. Some of the key techniques I have mastered include:

1. Collection and Cultivation of PGCs
   I have learned the process of isolating and growing PGCs from chicken embryos.

2. Injection of PGCs into Chicken Embryos
   A pivotal part of the research involves injecting PGCs into developing chicken embryos. This technique allows us to investigate how esxogenous PGCs compete with endogenous PGCs.

3. Freezing and Thawing PGCs
   Cryopreservation of PGCs is critical for long-term storage and future use. I have learned the methods to freeze and thaw PGCs without compromising their viability, ensuring we can maintain viable cells for later use in our experiments.

Key Experiments Completed

The skills mentioned above have been put to good use in several exciting experiments. Here is a quick summary of the experiments I have worked on:

1. Creation of GFP-PGCs from X33 Breed (INRAE)
   In collaboration with the INRAE, I have been involved in creating GFP-PGCs from the X33 breed.

2. Collection and Culture of PGCs from Three Breeds
   I have also worked on collecting and culturing PGCs from these three breeds: layers, broilers, and Bresse. These cells are essential for the follow-up experiments, as they allow us to study breed-specific variations in PGC behavior and function.

Next Steps in the Research

Looking ahead, the next phase of our research will involve extending our work with GFP-PGCs. Here are the key steps we will take:

1. Creation of GFP-PGCs from Three Different Breeds
   We will continue to create GFP-PGCs, but this time, we will focus on three distinct chicken breeds: layers, broilers, and Bresse.

2. Injection of GFP-PGCs into Different Chicken Breeds
   Once the GFP-PGCs are ready, we will inject GFP-PGCs of each breed into embryos from the three different host breeds (layers, broilers, and Bresse).

3. Study of Competition between Host and Injected PGCs
   The core focus of the upcoming experiments will be on understanding the competition between the exogenous PGCs and the endogenous PGCs. This will help us better understand the dynamics of PGC competition and the potential for using transgenic PGCs for poultry breeding and conservation.

4. Investigation of Gamete Tissues
   Ultimately, we aim to investigate the gamete tissues in these embryos to determine how the injected GFP-PGCs contribute to the generation of viable eggs and sperm.

5. Improve freezing process

   We want to develop a new protocol to cryopreserve the PGCs and increase the survival rate of the cells after the process of freezing – thawing.