ANOOP KUMAR VITELLOGENESIS 21 .My Name is Anoop kumar I am Student of Central University of Uttarakhand ( HNBGU ) This PPT is Habitat Management and Techniques

My Name is Anoop kumar
I am Student of Central University of Uttarakhand ( HNBGU )
This PPT is Habitat Management and Techniques 👍

1. HEMVATI NANDAN BAHUGUNA GARHWAL UNIVERSITY SRT CAMPUS BADSHAHITHAUL DEPARTMENT OF ZOOLOGY TOPIC: VITELLOGENESIS PAPER: DEVELOPMENT BIOLOGY SUBMITTED BY: ANOOP KUMAR M.SC. ZOOLOGY 1 ST SEM ROLL NO. 25

2. POINTS TO BE DISCUSSED: DEFINITION OF VITELLOGENESIS CHARACTERISTIC TYPES OF YOLK GRANULAR YOLK YOLK PLATELETS FUNCTION REFERENCE

3. DEFINITION OF VITELLOGENESIS From Latin Vitellus – yolk & Genero – produce Vitellogenesis (also know as yolk deposition) is the process of yolk formation via nutrients being deposited in the oocyte , or female germ cell involved in reproduction of lecithotrophic organisms. In insects, it starts when the fat produces vitellogenin protein.

4. CHARACTERISTIC Y olks is the most usual form of food storage in the egg. Yolks appear in the oocyte in the secondary period of their growth celled vitellogenesis . Thus, the formation and deposition of yolks is known as vitellogenesis . Y olks is a complex variable assembled component. The principle component are protein, phospholipid & fats in different combination. D epending upon these component yolks is distinguished into protein yolks & fatty acid For eg - the avain contain 48.19% water, 16.6% protein, 32.6% phospholipids & fats , & 1% carbohydrates

5. TYPES OF YOLKS In animals, the yolk is of 3 types 1.Granular yolk 2. Yolk platelets 3. Yolk sphere

6. 1. GRANULAR YOLK I t is the characteristic feature of invertebrates & lower chordates likes amphooxus & tunicates. T he protein yolk is composed of fine granules which is evenly distributed into the cytoplasm of oocyte . 2. YOLK PLATELETS It is found is most vertebrates like cyclostomes, lung fishes, amphibians, reptiles,& birds. T he yolk occur in the form of large granules known as yolk platlets . The yolk platlets are oval & flattened in one plane.

7. THE YOLK PLATLETS CONTAIN 2 MAIN PROTEINACEOUS 1 P hosphovitin - it is highly phosphorylated protein Its molecular weight is 35000 Dalton, 8.5% of phosphorus content is present. 2. L ipovittelin – it is a protein major bound to lipid. I ts molecular weight is 4000 D, 17.5% lipid content is present. I n yolk platlets , 2 molecules of phosphovitin are associated with one molecule of lipovittelin a structural unit. T he units are being arranged in platelets in a crystalline lattice with a regular hexagonal packing The yolk platelets of bony fish have fat droplets inside its mass

8. 3. YOLK SPHERE The yolk of birds, reptile & bony fishes lies in a compact mass in the interior of a egg. The cytoplasm is restricted to their layar on the surface of the egg

9. FUNCTION It store food in the egg It influence the differentiation of neoplasm pattern of cleavage. The size of egg is determined by amount if yolk present in it. Its responsible for morphogenetic movement of elastomer during gastrulation The mature of development of an organism is governed by amount of yolk present in the egg

10. REFERENCE DEVELOPMENT BIOLOGY (P.C JAIN); SEVENTH EDITION: VISHAL PUBLICATION(2014) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7901893/