Biochemistry of fertilization.

Here provided contents for learning that what are the male and female gametes. How to they form? And described how to both gametes fused (fertilization)on the molecular basis.

1. UTTAM MEMORIAL COLLEGE PATELPALI RAIGARH (C.G.) SUB- GAMETE BIOLOGY TOPIC - BIOCHEMISTRY OF FERTILIZATION GUIDED BY-. SUBMITTED BY – MISS VIJAYA MA’AM KRISHN KUMAR SAHU ( HOD IN ZOOLOGY). ( MSc. ZOOLOGY 2 ND SEM.)

2. SYNOPSIS :- Introduction Definition Types of fertilization Biochemical factor involved in fertilization Steps of fertilization:- ➪ Capicitation of sperm ➪ Arrival on secondary oocyte ➪ Acrosomal reaction ➪ Cortical reaction ➪ Sperm entry ➪ Plasmogamy ➪ Karyogamy ➪ Amphimixis 6. Significance of fertilization Conclusion Reference

3. 1. 𝑰𝑵𝑻𝑹𝑶𝑫𝑼𝑪𝑻𝑰𝑶𝑵 :- Fertilization is the fusion of male and Female gamete. The process involved the fusion of an oocyte with sperm and creating a single diaploid zygote. And zygote devloped into new individual. During sexual intercourse millions of sperm are deposited into the vagina, most of them will die cause of alkaline and acidic nature of vagina and uterus. Many sperm will survive and swim through the cervical mucus towards uterus and fallopian tube. Finally sperm reached into the secondry oocyte, then sperm release proteolytic and hydrolytic enzymes ,and fertilize the oocyte, These whole process is called fertilization.

4. 𝑺𝑻𝑹𝑼𝑪𝑻𝑼𝑹𝑬 𝑶𝑭 𝑺𝑷𝑬𝑹𝑴 :- Sperm is the male gamete derived from Greek word sperma (seed). It consists of 3 parts head, midpiece and tail . HEAD :- oval shaped structure contains Acrosome and nucleus . Acrosomal rigion contains different type of proteolytic Enzymes such as acrosin , trypsin, hyaluronidase and proteases,during acrosomal reaction it penitrate the layer of sec. Oocyte.

5. 𝑪𝒐𝒏𝒕𝒊𝒏𝒖𝒐… 2. 𝒎𝒊𝒅𝒑𝒊𝒆𝒄𝒆 :- contains cellular elements like mitochondria, centriole .It is made up by axial filaments. Mitochondria which provides enery to survival. And motility. Length :- 7.5 mm. Width :- 1 mm. 3. 𝑻𝒂𝒊𝒍 :- Consist Of microtubules and responsible for mobility.

6. Ovum is the Spherical ,rounded non motile , female haploid gamete. And size of ovum depend on organism It has many envelopes:- 𝒁𝒐𝒏𝒂 𝒑𝒆𝒍𝒍𝒖𝒄𝒊𝒅𝒂: - it is acellular thick transparent envelope of ovum. Zona pellucida glycoproteins are responsible for species-restricted binding of sperm to unfertilized eggs, inducing sperm to undergo acrosomal exocytosis, and preventing. 𝑪𝒐𝒓𝒐𝒏𝒂 𝒓𝒂𝒅𝒊𝒂𝒕𝒂 :- it is outer thicken coat formed of radially follicular cell, basically it is group of follicular cell. 𝑺𝑻𝑹𝑼𝑪𝑻𝑼𝑹𝑬 𝑶𝑭 𝑶𝑽𝑼𝑴:-

7. 2. 𝑫𝑬𝑭𝑰𝑵𝑰𝑻𝑰𝑶𝑵:- Fertilization is the sequence of corordinated molecular events , involving the merging of the sperm with egg ,the fusion of pronuclei and intermingling of maternal and paternal chromosomes.process called molecular basis of fertilization

8. 3.𝑻𝒀𝑷𝑬𝑺 𝑶𝑭 𝑭𝑬𝑹𝑻𝑰𝑳𝑰𝒁𝑨𝑻𝑰𝑶𝑵 On the basis of mode:- 1. Cross fertilization 2. Self fertilization On the basis of place/location: - 1. External 2. Internal fertilization On the basis of nomber of sperm: - 1.polyspermy 2. Monospermy

9. 4.𝑩𝑰𝑶𝑪𝑯𝑬𝑴𝑰𝑪𝑨𝑳 𝑭𝑨𝑪𝑻𝑶𝑹 𝑰𝑵𝑽𝑶𝑳𝑽𝑬𝑫 𝑰𝑵 𝑭𝑬𝑹𝑻:- Acrosin . Lysine. Fertilizin . Antifertilizin . Zp matrix- zp1,zp2,zp3. Hyaluronidase . Calcium. Pottasium . Hco3. Etc….

10. 5. 𝑺𝑻𝑬𝑷𝑺 𝑶𝑭 𝑭𝑬𝑹𝑻𝑰𝑳𝑰𝒁𝑨𝑻𝑰𝑶𝑵 𝑪𝒂𝒑𝒊𝒄𝒊𝒕𝒂𝒕𝒊𝒐𝒏 𝒐𝒇 𝒔𝒑𝒆𝒓𝒎 :- Surving Ability or capacity of of sperm is called capacitation. Capacitation is the step of sperm maturation that leads to their capability of fertilization. Capacitation involves chemical and physiological changes to the sperm cells.the sperm can penetrate the zona pellucida

11. Process of capacitation:- 3 process happened in capacitation . Efflux of cholesterol: - cholesterol are removed in anterior head By albumin Protein. Then lipid and protein react with zona pellucida receptor. And help in fertilization. 2. Protein changes: - It removed the protein which block the interaction to the oocyte . 3. K+ & ca+ ion channel interaction:- P.m. Of sperm have ca and k ion channels. K+ ion continuously goes outside , thus k+ are positive but continuously going outside. Then Environment will be negative. Then any ca+ ion comes inside sperm cell . Ca+ ion activate the dyenin protein which help in movement of tail sperm.

12. 2. 𝑨𝒓𝒓𝒊𝒗𝒂𝒍 𝒕𝒐 𝒕𝒉𝒆 𝒔𝒆𝒄. 𝑶𝒐𝒄𝒚𝒕𝒆:- Process that ejaculated sperm reached into secondary oocye by the help of their movements process called sperm arriving mechanism.

13. 3. 𝑨𝒄𝒓𝒐𝒔𝒐𝒎𝒂𝒍 𝑹𝒆𝒂𝒄𝒕𝒊𝒐𝒏:- At first sperm bind to the corona radiata layer. Acrosomal pore are activated and Reduce hydrolytic enzymes drill the corona radiata by drilling movement. Binding of sperm to the zp3 receptor . Now sperm reached into zona pellucida envelope,and zp have special zp3 receptor, now sperm attatch to the receptor and release antifertilin , hyaluronidase , cathepsin , acrosin , zona lysin and other proteolytic Enzymes released by sperm this whole process is known as as acrosomal reaction। .

14. 4. 𝑶𝒐𝒄𝒚𝒕𝒆 𝑨𝒄𝒕𝒊𝒗𝒂𝒕𝒊𝒐𝒏 :- Plasma membrane and oolema of oocyte rises slightly upwards and form reception cone . It works as a:- It form a reception cone for incoming Sperm. It regulates metabolic activations such as – protein synthesis. It block the polyspermy .

15. 5. 𝑪𝒐𝒓𝒕𝒊𝒄𝒂𝒍 𝑹𝒆𝒂𝒄𝒕𝒊𝒐𝒏:- Cortical Reaction are existing after fusion of gamete . Cortical granules are move on the perivitelline space . It makes hard the zona pellucida And block the polyspermy.

16. 6. 𝑷𝒍𝒂𝒔𝒎𝒐𝒈𝒂𝒎𝒚:- Fusion of sperm cell cytoplasm with ovum cytoplasm Called plasmogamy . Plasmogamy is a stage in the sexual reproduction stage in which the protoplasm of two parent cells fuse without the fusion of nuclei, effectively bringing two haploid nuclei close together in the same cell.

17. 7. 𝑲𝒂𝒓𝒚𝒐𝒈𝒂𝒎𝒚:- Fusion of pronuclei of two different cell is called Karyogamy. Karyogamy is the final step in the process of fusing together two haploid eukaryotic cells, and refers specifically to the fusion of the two nuclei.

18. 8. 𝑨𝒎𝒑𝒉𝒊𝒎𝒊𝒙𝒊𝒔:- Fusion of two cell’s haploid chromosomes Is called amphimixis Amphimixis is a type of sexual reproduction in which the male and female parents’ gametes, i.e. the ovum and spermatozoa, fuse during fertilization, resulting in the creation of zygotes. The zygote will then result in the formation of offspring that are genetically unique from their parents.

19. 6. 𝑺𝒊𝒈𝒏𝒊𝒇𝒊𝒄𝒂𝒏𝒄𝒆 𝒐𝒇 𝒇𝒆𝒓𝒕𝒊𝒍𝒊𝒛𝒂𝒕𝒊𝒐𝒏:- . • The significance of fertilization are as follows.. It rises to formation of a new organism
It is the successful formation of zygote by the fusion of sexgerm cells that are female and male gametes.
It leads to a successful reproduction attempt.
It ultimately leads to a replication of a new organism as an offspring.

20. 7. 𝑪𝑶𝑵𝑪𝑳𝑼𝑺𝑰𝑶𝑵:- 𝑻𝒘𝒐 𝒉𝒂𝒑𝒍𝒐𝒊𝒅 𝒇𝒆𝒎𝒂𝒍𝒆 𝒂𝒏𝒅 𝒎𝒂𝒍𝒆 𝒈𝒂𝒎𝒆𝒕𝒆 ,𝒄𝒐𝒎𝒃𝒊𝒏𝒆 𝒂𝒏𝒅 𝒇𝒐𝒓𝒎 𝒂 𝒅𝒊𝒑𝒍𝒐𝒊𝒅 𝒛𝒚𝒈𝒐𝒕𝒆. 𝒛𝒚𝒈𝒐𝒕𝒆 𝒅𝒆𝒗𝒍𝒐𝒑𝒆𝒅 𝒊𝒏𝒕𝒐 𝒆𝒎𝒃𝒓𝒚𝒐 . 𝒆𝒎𝒃𝒓𝒚𝒐 𝒅𝒆𝒗𝒍𝒐𝒑𝒆𝒅 𝒊𝒏𝒕𝒐 𝒖𝒕𝒆𝒓𝒖𝒔. 𝒇𝒆𝒓𝒕𝒊𝒍𝒊𝒛𝒂𝒕𝒊𝒐𝒏 𝒕𝒂𝒌𝒆𝒔 𝒑𝒍𝒂𝒄𝒆 𝒊𝒏 𝒂𝒎𝒑𝒖𝒍𝒂 𝒂𝒏𝒅 𝒊𝒔𝒕𝒉𝒎𝒖𝒔,𝒂𝒓𝒆𝒂 𝒔𝒐 𝒄𝒂𝒍𝒍𝒆𝒅 𝒊𝒕 𝒂𝒎𝒑𝒖𝒍𝒍𝒂𝒓𝒚 𝒊𝒔𝒕𝒉𝒎𝒖𝒔 𝒋𝒖𝒏𝒄𝒕𝒊𝒐𝒏. 𝒅𝒖𝒓𝒊𝒏𝒈 𝒔𝒆𝒙𝒖𝒂𝒍 𝒊𝒏𝒕𝒆𝒓𝒄𝒐𝒖𝒓𝒔𝒆 1 𝑴𝒍 𝒆𝒋𝒂𝒄𝒖𝒍𝒂𝒕𝒆𝒅 𝒔𝒑𝒆𝒓𝒎 𝒄𝒐𝒏𝒕𝒂𝒊𝒏𝒔 80 𝒕𝒐 120 𝒎𝒊𝒍𝒍𝒊𝒐𝒏𝒔 𝒔𝒑𝒆𝒓𝒎,𝒂𝒏𝒅 𝒊𝒏𝒕𝒓𝒆𝒔𝒕𝒊𝒏𝒈 𝒊𝒔 𝒕𝒉𝒂𝒕 𝒐𝒏𝒍𝒚 𝒐𝒏𝒆 𝒔𝒑𝒆𝒓𝒎 𝒐𝒇 𝒕𝒉𝒆𝒎 𝒇𝒆𝒓𝒕𝒊𝒍𝒊𝒛𝒆 𝒕𝒉𝒆 𝒐𝒗𝒖𝒎.

21. 8. 𝑹𝑬𝑭𝑬𝑹𝑬𝑵𝑪𝑬:- 𝑯𝒖𝒎𝒂𝒏 𝒂𝒏𝒐𝒕𝒐𝒎𝒚 𝒂𝒏𝒅 𝒑𝒉𝒚𝒔𝒊𝒐𝒍𝒐𝒈𝒚 𝒃𝒐𝒐𝒌 𝒃𝒚 𝒅𝒓. 𝑨𝒏𝒂𝒏𝒕 𝒑𝒓𝒂𝒌𝒂𝒔𝒉 𝒈𝒖𝒑𝒕𝒂. 𝒃𝒚 𝒏𝒆𝒕…