Jo FaY wrote...
>I'm not very knowledgeable about mammalian chromosome, but some plants can
>have variable numbers of extra, small chromosome. In the Allium species
>(chives, garlic, etc) these are called B chromosomes or supernumary
>Some mammals also have B chromosomes, but I can't remember any names
>as I only studied chives in my project at York.
I think you may be referring to double minute chromosomes in mammalina cells
ex. DHFR cotaining double minute in Chinese Hamster Ovary Cells (CHO)
or the Mouse DOuble minute Gene (mdm2)
Also thy have found stable linear chromosome like fragements and episomal like
chromosomes in mammalian cells..... though in most cases even with the ability to
automonously replicate they are lost from cultured cells in the absence of selection.
Graham Dellaire Snail Mail:
Red Cross, Research
McGill Univeristy Montreal Blood Services
Faculty of Medicine 3131 Sherbrooke St. East
Div. of Experimental Medicine Montreal, QC, Canada
E-mail: popa0206 at po-box.mcgill.ca H1W 1B2
B2XE at musicb.mcgill.ca
Fax: (514) 525 0881
Voice: (514) 527 1501 ext 175