INTERNATIONAL UNIVERSITY, VNU-HCM
School of Biotechnology
GROUPWORK
STEM CELL BIOLOGY (BT212IU)
Associate Professor Bùi Hồng Thủy, PhD
GROUP 4 – LIST OF MEMBERS
1. Lê Nguyễn Lam Ngọc (Group Leader) BTBTIU18345
2. Dương Quý Hảo BTBTIU18073
3. Nguyễn Ngọc Bảo Hân BTBTIU18362
4. Tạ Thị Minh Thu BTBTIU18369
5. Nguyễn Thị Trang BTBTIU18248
6. Nguyễn Lê Uyên Vy BTBTIU18284
, Topic: Describe the process of oocyte growth, maturation, and fertilization until the first cell
division in zygote (the first mitotic division). Then discuss some specific molecules involved
in this process.
Developmental biology studies how genes regulate cell growth, how cells differentiate from stem
cells, and how gastrulation and organogenesis happen. The goals of developmental biology are to
discover alternative treatment for diseases and to repair damaged tissues (Lanza and Atala, 2013).
From the lecture, we went through many aspects of developmental biology. Here we focus on
oocyte development stages and early embryogenesis in mouse. Additionally, we look at some
molecular and epigenetic factors related to the aforementioned process.
A. OOCYTE DEVELOPMENT STAGES
In the early stage of oogenesis, primordial germ cells and oogonia proliferate by mitosis, whose
cell cycles are similar to somatic cells’. Briefly, cells grow and prepare cellular contents G1 and
G2, where DNA synthesis takes place between two phases. Then, M phase happens for cell
division. However, these cells later undertake meiosis to reduce their chromosomal numbers,
unlike the somatic cells. The process is associated with follicle and oocyte growth to ensure
oocyte’s maturity (nuclear maturation, cytoplasmic maturation, and epigenetic maturation).
Furthermore, a huge number of oocytes undergo selections and atresia to find out the best one for
fertilization.
Follicle development Oocyte development Characteristics
Before birth
Primordial germ cell (2n) Formation, migration, and proliferation
Oogonium (2n) Cell proliferation by mitosis
Primary oocyte,
GV oocyte (2n)
- Leptotene
First meiotic arrest at diplotene in prophase I
- Zygotene
- Pachytene
- Diplotene
After birth (Reproductive age)
Breakdown of germ cell nest
Primordial follicle
Primary oocyte Single layer of squamous pre-granulosa cells
(Non-growing)
(flat epithelial cells) surrounding the oocyte
Transformation from pre-granulosa cells to
cuboidal follicular cells
Primary follicle Primary oocyte, GV oocyte,
Theca cell formation (separated from the
(Growing) growing oocyte (2n)
granulosa cells by basement membrane)
Zona pellucida formation
School of Biotechnology
GROUPWORK
STEM CELL BIOLOGY (BT212IU)
Associate Professor Bùi Hồng Thủy, PhD
GROUP 4 – LIST OF MEMBERS
1. Lê Nguyễn Lam Ngọc (Group Leader) BTBTIU18345
2. Dương Quý Hảo BTBTIU18073
3. Nguyễn Ngọc Bảo Hân BTBTIU18362
4. Tạ Thị Minh Thu BTBTIU18369
5. Nguyễn Thị Trang BTBTIU18248
6. Nguyễn Lê Uyên Vy BTBTIU18284
, Topic: Describe the process of oocyte growth, maturation, and fertilization until the first cell
division in zygote (the first mitotic division). Then discuss some specific molecules involved
in this process.
Developmental biology studies how genes regulate cell growth, how cells differentiate from stem
cells, and how gastrulation and organogenesis happen. The goals of developmental biology are to
discover alternative treatment for diseases and to repair damaged tissues (Lanza and Atala, 2013).
From the lecture, we went through many aspects of developmental biology. Here we focus on
oocyte development stages and early embryogenesis in mouse. Additionally, we look at some
molecular and epigenetic factors related to the aforementioned process.
A. OOCYTE DEVELOPMENT STAGES
In the early stage of oogenesis, primordial germ cells and oogonia proliferate by mitosis, whose
cell cycles are similar to somatic cells’. Briefly, cells grow and prepare cellular contents G1 and
G2, where DNA synthesis takes place between two phases. Then, M phase happens for cell
division. However, these cells later undertake meiosis to reduce their chromosomal numbers,
unlike the somatic cells. The process is associated with follicle and oocyte growth to ensure
oocyte’s maturity (nuclear maturation, cytoplasmic maturation, and epigenetic maturation).
Furthermore, a huge number of oocytes undergo selections and atresia to find out the best one for
fertilization.
Follicle development Oocyte development Characteristics
Before birth
Primordial germ cell (2n) Formation, migration, and proliferation
Oogonium (2n) Cell proliferation by mitosis
Primary oocyte,
GV oocyte (2n)
- Leptotene
First meiotic arrest at diplotene in prophase I
- Zygotene
- Pachytene
- Diplotene
After birth (Reproductive age)
Breakdown of germ cell nest
Primordial follicle
Primary oocyte Single layer of squamous pre-granulosa cells
(Non-growing)
(flat epithelial cells) surrounding the oocyte
Transformation from pre-granulosa cells to
cuboidal follicular cells
Primary follicle Primary oocyte, GV oocyte,
Theca cell formation (separated from the
(Growing) growing oocyte (2n)
granulosa cells by basement membrane)
Zona pellucida formation
