Date of Award

Spring 1981

Document Type


Degree Name

Master of Science (MS)


Biological Sciences



Committee Director

Paul J. Homsher

Committee Member

Edward Wortham

Committee Member

Jack M. Rary

Committee Member

Daniel Sonenshine

Call Number for Print

Special Collections LD4331.B46 H37


A transmission electron microscope analysis of the changes that occur in the nuclear chromatin and the Feulgen-positive areas of the oocyte cytoplasm as the female develops, feeds and mates is described. The description includes analysis of oocytes from three types of females: unfed, unmated; fed, unmated; and fed, mated. In all types, dense material passes through the extremely porous nuclear membrane where it accumulates in the cytoplasm.

Nuclei of previtellogenic oocytes appear the same in all females studied. Fibrillar bodies and up to four large nucleoli are seen. No typical chromatin is seen, but structures resembling nucleosomes appear throughout the nucleus.

Nuclei of early vitellogenic oocytes have increased numbers of nucleosornes. At least one nucleolus is present and fibrillar bodies are seen.

Nuclei of late vitellogenic oocytes have lost almost all nucleosomes from the nucleus and the nucleoplasmic appearance is noticeably different from previously described stages. Only one large nucleolus is present and no fibrillar bodies are seen.

All pedicellar areas reveal no deposition of material resembling chromatin that was seen as Feulgen-positive areas in histological sections. Extraction of DNA during processing may be the cause of the lack of chromatin found at the oocyte-pedicel interface.


In Copyright. URI: This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).