MedicalResearch.com Interview with:
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Dr. Avidor-Reiss[/caption]
Tomer Avidor-Reiss, Ph.D.
Professor, College of Natural Sciences and Mathematics
Department of Biological Sciences
University of Toledo
Toledo, OH 43606
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Most dividing cells in the body need exactly two centrioles for normal cell division and development. Abnormalities in centriole number can cause cancer and devastating developmental defects. Because of this importance of centriole number and because all cells originate from the zygote – the product of the sperm and egg – it makes sense that the zygote should possess two centrioles, as well.
However, the egg does not contain any centrioles, so the sperm is the sole contributor of the centrioles; and yet, it is currently thought that the sperm contains only one centriole. This is problematic because supposedly that leaves the zygote with only one centriole, even though it must propagate cells with two centrioles. In the past, we found that insect sperm have an atypical centriole that escaped discovery because it is so different. We therefore hypothesized that humans may also have an atypical sperm centriole.
Our new paper shows that in human sperm there exists, in addition to the known centriole, a second centriole that deviates from the typical structural and composition that is expected from a centriole. Although it looks very different from any centriole ever described, we found that it functions in an
in vitro functional assay. Furthermore, during fertilization, it performs the functions traditionally associated with centrioles. Together, this resolves a 50-year-long debate regarding the centrioles of human sperm; the sperm contains two functional centrioles, despite that one is atypical.