The cooperative view: New evidence suggests a symbiogenetic origin for the centrosomeMay 07, 2008MBL, WOODS HOLE, MA - There are two ways in which cooperation is the theme of a paper published this week by Mark Alliegro and Mary Anne Alliegro, scientists at the Marine Biological Laboratory's (MBL) Josephine Bay Paul Center. One is revealed in the paper's acknowledgements, where the Alliegros thank those who helped them after Hurricane Katrina completely disrupted their laboratory at Louisiana State University (LSU) in New Orleans - and their lives - in 2005. The second is the paper's scientific theme: the origin of the centrosome, a component of animal cells that functions in cell division. In their paper, published in Proceedings of the National Academy of Sciences, the Alliegros give evidence that the centrosome evolved through symbiogenesis - in which previously independent organisms fuse, become mutually dependent, and over time, become a single composite organism - rather than by the evolutionary process of random, heritable mutations and natural selection. The Alliegros moved to the MBL permanently in September 2007, after two years of attempting to forge on in a devastated New Orleans. "We realized, if we stayed there, our research program would not survive," says Mark Alliegro, who was a professor at LSU Health Sciences Center. The origin of the centrosome, their paper points out, has been controversial for many years. The theory of symbiogenesis as a mechanism of evolution has also stirred debate since it was introduced in the 1920s and subsequently elaborated in the 1960s by Lynn Margulis of University of Massachusetts, Amherst. Today, only two cellular components - the mitochondria and the chloroplasts - are generally accepted by evolutionary biologists as having a symbiogenetic origin. The Alliegros' paper suggests that centrosomes are another likely candidate. They base their argument on evidence that the centrosomes, which they obtained from the eggs of the surf clam Spisula, contain RNA that is likely a remnant of a once-independent, simpler genome that was incorporated by symbiosis. "Most animal genes have introns, regions that are transcribed into RNA but then spliced out," says Alliegro. "But if you look at viral genes or bacterial genes, they have little or no introns. It turns out the genes for Spisula centrosomal RNAs have few or no introns. They are a special set of RNAs that derived from intron-poor or intron-less genes, which may very well support the idea that they come from a simpler organism, like a virus or bacteria." The Alliegros lost their RNA library due to Katrina, and in their paper they acknowledge Gloria Giarratano of LSU Health Sciences Center, who helped them re-clone the library from DNA they recovered in the hurricane's aftermath. They also thank Bruce and Sharon Waddell of Slidell, Louisiana, in whose home they lived after Katrina, and where "our laboratory was resurrected in part from the dining room table"; as well as Carol Burdsal and other colleagues at Tulane University, where they temporarily set up a new lab. Robert Palazzo of Rensselaer Polytechnic Institute, a longtime visiting investigator at the MBL, is acknowledged for providing the centrosome preparation for the original RNA extractions as well as advice and encouragement. This work was supported by the National Institutes of Health as well as post-Katrina emergency recovery funds from the Society for Developmental Biology. Marine Biological Laboratory |
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| Related Centrosome Current Events and Centrosome News Articles Protein helps cells duplicate correctly, avoid becoming cancer A Purdue University researcher has discovered that the absence of certain proteins needed for proper cell duplication can lead to cancer. New insight into human ciliopathy In the September 1st issue of G&D, Dr. Karen Oegema (UCSD) and colleagues identify the molecular basis of the lethal developmental disorder, hydrolethalus syndrome, and reveal that hydrolethalus syndrome actually belongs to the emerging class of human ciliopathy diseases. Link unraveled between chromosomal instability and centrosome defects in cancer cells In a new study, Dana-Farber Cancer Institute scientists disprove a century-old theory about why cancer cells often have too many or too few chromosomes, and show that the actual reason may hold the key to a novel approach to cancer therapy. New advances in cancer research to be highlighted at University of Leicester A scientist whose work is key to understanding how cancer cells divide and spread in the body is to present advances in his latest research at a public forum to be held at the University of Leicester. Vanderbilt scientists invent world's smallest periscopes A team of Vanderbilt scientists have invented the world's smallest version of the periscope and are using it to look at cells and other micro-organisms from several sides at once. CSHL scientists discover link between control of chromosome duplication and segregation Before a cell can divide into two, first it must duplicate its genetic material--the DNA packed in its chromosomes. The two new sets of chromosomes then have to be separated from one another and correctly distributed to the resulting "daughter" cells, so that both daughter cells are genetically identical to the original, or "parent," cell. Hopkins researchers piece together gene 'network' linked to schizophrenia Reporting this week in the Archives of General Psychiatry, researchers at the Johns Hopkins University School of Medicine have uncovered for the first time molecular circuitry associated with schizophrenia that links three previously known, yet unrelated proteins. 'Network' approach identifies potential breast cancer susceptibility gene Like a crossword-puzzle solver who uses the letters in some answers to figure out others, researchers at Dana-Farber Cancer Institute and an international group of collaborators have used data on genes involved in inherited forms of breast cancer to identify a gene linked to non-hereditary cases of the disease. LSUHSC research finds evidence of RNA in structures essential to cell division Research led by Mark Alliegro, PhD, Professor of Cell Biology and Anatomy at Louisiana State University Health Sciences Center at New Orleans, provides evidence for the first time that centrosomes, which play a key role in cell division, may carry their own genetic machinery, answering a controversial question of long standing. RNA found in the cellular centrosome of surf clams Researchers at Rensselaer Polytechnic Institute, the Marine Biological Laboratory (MBL) in Woods Hole and Louisiana State University (LSU) Health Sciences Center have discovered the presence of the genetic material RNA in the centrosome, the organizing structure inside each cell that assures proper cell division. More Centrosome Current Events and Centrosome News Articles |
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