Localization of the micromere material in the cytoplasm of the egg of Arbacia

✍ Scribed by Harnly, Morris H.

• Book ID: 102888631
• Publisher: John Wiley and Sons
• Year: 1926
• Tongue: English
• Weight: 720 KB
• Volume: 45
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1400450112

✦ Synopsis

I n recent years the development of the microdissection methods, both by free hand and by machine, has made possible the fragmenting of single eggs with the plane of fragmentation arid the size of fragments controlled. By means of the free-hand method, the following work was carried out to determine the localization of the micromere material in the unfertilized egg and fertilized egg of the seaurchin. The work was carried on in the Marine Biological Laboratory at Woods Hole.

The relative position of micropyle and iiucleus in the mature e g g of Arbacia was determined by the use of Chinese ink. The nucleus, like that of Strongylocentrotus as shown by Boveri, was found to lie at any point with reference to the micropyle in either the animal or vegetal hemisphere.

Mature eggs were fragmented free-hand with a glass hair under the biiiocular microscope. The female pronucleus can be seen easily and the fragments readily sorted out and transferred with a lip pipette to sea-water in salt-cellars. If the eggs a r e in good condition, the fragments round up in a short time.