Animal family tree rearranged; how E. coli evades the immune system; pharmacological chaperones and misfolded proteins
December 13, 2013|
BRUNO VELLUTINIA whole-genome sequencing study on Mnemiopsis leidyi has moved comb jellies to the base of the animal family tree, ousting sponges from that position. M. leidyi was the first member of the Ctenophores lineage to have its genome fully sequenced.
“There’s been a lot of debate about early animal evolution,” Boston University biologist John Finnerty, who was not involved in the study, told The Scientist. “The major early animal lineages had all been represented by at least one species with a sequenced genome with the exception of the Ctenophores,” Finnerty said, “so this really was a key piece of missing evidence.”
Scientists from the National Human Genome Research Institute who sequenced and analyzed the M. leidyi genome unearthed comparative genetic evidence to suggest that the comb jelly was the most basal animal. The team examined M. leidyi along with genome sequences for 12 species from other animal phyla.
“Like any good genome that has been sequenced, the results of this study generate more questions than answers,” said Vanderbilt University’s Antonis Rokas. “If the placement of Ctenophores is correct,” he added, “it really changes quite a bit of the text book interpretation that we have about the evolution of morphological complexity.”
ISABEL GORDOEscherichia coli mutants can evolve to resist engulfment by mouse macrophages in as few as four days, or 500 generations, scientists have found. Researchers from Portugal’s Instituto Gulbenkian de Ciência challenged E. coli by exposing them to macrophages, finding those bacteria that evolved to evade engulfment were capable of infecting mice.
In an e-mail, La Trobe University’s Ashley Franks told The Scientist that studies like this demonstrate “a medical consequence of what is occurring with genetic rearrangements of the DNA sequence by the microbes themselves.”
WIKIMEDIA, GEORGE SHUKLINA mouse model that does not respond to gonadotrophin-releasing hormone (GnRH) because of a mutation that causes misfolding of the GnRH receptor can be treated with a pharmacological chaperone, scientists from Texas Tech University have found. Their work is the latest study showing that pharmacological chaperones can successfully reverse disease-causing mutations related to misfolded proteins in mice.
“Chaperones are a terrific idea,” Brandeis University’s Dagmar Ringe, a professor of biochemistry and chemistry who was not involved in the work, told The Scientist. “There are so many cases where this type of intervention would actually be really useful.”
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