Scientific Presentations of Zoology 2.pptx

Scientific presentations on zoology

1. Practical “ Study of fertilization, and early development of frog through induced spawning under labor try condition “

2. Material Injection syringe Gonadotrophic realizing hormone agnostic Dopamine antagonist Lithobates pippins

3. Background It is well known that many anurans do not reproduce easily in captivity. Some methods are based on administration of mammalian hormones such as human chorionic gonadotropin, which are not effective in many frogs . There is a need for simple, cost-effective alternative techniques to induce spawning .

4. It is well known that many anurans do not reproduce easily in captivity. They either suffer from confinement stress or critical environmental cues are missing in captivity, resulting in the inhibition of reproduction I t is possible to simulate natural climatic conditions in captivity to induce breeding but for others hormonal treatments are required.

5. One method of spawning induction in amphibians requires multiple injections of the LH-like hormone human chorionic gonadotropin (chg.). Another approach is to inject a brain decapeptide, gonadotropin-releasing hormone (GnRH), which is the main endogenous stimulator of LH. Gnarl specifically activates Gnarl receptors on LH-producing cells in the pituitary and stimulates endogenous LH production and release , which in turn acts on the gonads to increase sex steroid production and spawning.

6. Method / Procedure Our new method is based on the injection of a combination of a gonadotropin-releasing hormone (Gnarl) agonist and a dopamine antagonist. We have named this formulation AMPHIPLEX , which is derived from the combination of the words amphibian and am plexus. This name refers to the specific reproductive behavior of frogs when the male mounts and clasps the female to induce ovulation and to fertilize the eggs as they are laid.

7. The use of the method and demonstrate its applicability for captive breeding in 3 different anuran families. It was used in-season, after short-term captivity and in frogs artificially hibernated under laboratory conditions. The AMPHIPLEX method was also effective in 3 Argentinian frogs, Ceratophrys ornate Ceratophrys canella and Odontophrynus Americanos

8. Hormone-based methods for captive breeding are not designed to induce sexual maturation. Rather, they are designed to induce timed release of egg and sperm so that fertilization may occur .

9. E m bryology in Frog

10. Embryology The study of animal development from fertilized egg to the formation of all major organ system.

11. A frog lays many eggs at one time. The eggs are covered with a jellylike coating. The haploid sperms fuse with haploid egg and form a diploid zygote. A fertilized egg have a color band called gray crescent, where the opposite side sperm enter in to egg. Fertilization in Frog :

12. Cleavage in frog embryo The first cleavage is meridional and divides the egg into 2 cell stage. The second cleavage is also meridional and right angle to the first and form the 4 cell stage. The third cleavage is horizontal and produces the 8 cell stage.

13. In cleavage egg cells divides into 32-cells

14. M orula A solid ball of cells is called morula . OR The next few cleavages producing 16 cell and then 32cell embryo called morula . .

15. BLASTULA Blastula: A hollow ball of cells is formed with the fluid filled cavity called Blastocoel. Upper hemisphere is Animal Pole . Lower hemisphere is vegetal pole.

16. Gastrulation is marked by the pushing inward ("invagination") of cells in the region of the embryo once occupied by the middle of the gray crescent. As gastrulation continues, three distinct  "germ layers"  are formed: Ectoderm Mesoderm Endoderm Gastrulation of Frog:

17. N eurula Neurula is an embryo in which neurulation occur. It involves the formation of an internal neural tube

18. This ectoderm grows up into two longitudinal folds, forming the  neural folds  stage. In time the lips of the folds fuse to form the  neural tube . The neural tube eventually develops into the brain and spinal cord. Neural Tube :

19. O rganogenesis The neurul tube will develop into the brain and spinal cord. The notochord forms from mesoderm. Differentiation of primary germ layers into tissues and organs.

20. D ifferentiation Organ starts to form after gastrulation. Embryonic tissue layers become to differentiate into specific tissues and organ systems.