File:Liver polyploidy 01.jpg

Liver Polyploidy

Polyploid hepatocyte mitoses in vitro with multipolar spindles and chromosome segregation defects.

• A - bipolar spindles were established and maintained by centrosome clustering (in about half of tetraploid mitoses)
• B C - centrosomes oriented on 3-4 distinct poles (reflecting either true multipolar spindles or alignment of prometaphase chromosomes from binucleated hepatocytes)
• D - octaploid hepatocytes established multipolar spindles with as many as 8 poles
• E - about 1% of cells in anaphase or telophase were oriented with tripolar spindles
• F - hepatocytes with 2 discrete mitotic spindles synchronized in metaphase
• G - hepatocytes with 2 discrete mitotic spindles synchronized in anaphase
• I - L - mitotic figures similar to those seen in cultured hepatocytes were also seen during hepatocyte proliferation in vivo

See supplementary movies for recordings of mitotic divisions.

Methods

• cells were fixed with methanol
• Primary antibodies for alpha-tubulin (clone DM1A, Sigma)
• Primary antibodies were detected with species-specific secondaries conjugated to Alexafluor 488 or Alexafluor 555 (Invitrogen).
• Nuclei were stained with 40 μg/ml Hoechst 33342 (Invitrogen).

Original File Name: Fig. 3 Nature09414-f3.2.jpg

Reference

Andrew W Duncan, Matthew H Taylor, Raymond D Hickey, Amy E Hanlon Newell, Michelle L Lenzi, Susan B Olson, Milton J Finegold, Markus Grompe The ploidy conveyor of mature hepatocytes as a source of genetic variation. Nature: 2010, 467(7316);707-10 PMID:20861837 | PMC2967727 | Nature

Reprinted by permission from Macmillan Publishers Ltd.

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