The Star Beacon; Ashtabula, Ohio

World, nation, state

December 22, 2013

Sex, gluttony and hoarding marked evolution of flowering plants

LOS ANGELES — Never mind the selfish gene — the cellular family history of the oldest living species of flowering plants is marked by enough sex and gluttony to earn a place in Shakespeare’s folio.

The powerhouse organelles inside cells of Amborella trichopoda, a woody shrub that grows only in the humid jungles of New Caledonia in the South Pacific, gobbled up and retained the entire genome from the equivalent organelles of four different species, three of moss and one of algae, according to a study of the plant’s mitochondrial DNA published this week in the journal Nature.

The results are the product of a years-long effort to sequence the full genome of the plant, a crucial step in solving what Charles Darwin once called “the abominable mystery” — the sudden flourishing long ago of several hundred thousand species of flowering plants.

An analysis of the nuclear DNA of the species, published in the same edition of Nature, revealed that the plant is the equivalent of the animal kingdom’s duck-billed platypus — a solitary sister left behind more than 100 million years ago by what became a panoply of flowering, or fruiting, plants.

The genome map, undertaken by the Amborella Genome Project, an international consortium of universities, enabled researches to infer the genetic makeup of the most recent common ancestor of A. trichopoda. It found that this ancestor likely evolved after an event that doubled its genome roughly 200 million years ago. Such an event could help explain what so baffled the father of evolutionary theory, the researchers said.

The map of the genome also serves as a reference point for explaining the evolution of many of the subsequent species that form the backbone of the human food chain.

But enough about nuclear DNA — let’s get to the sex and gluttony.

Researchers who mapped the genome of the plant’s mitochondria, the organelles that are the energy factories inside cells, were stunned at its size and diversity and by evidence of some intracellular shenanigans unsuitable for prime time.

“We think this paper will help bring mitochondrial sex out of the closet, if you will,” said Jeffrey D. Palmer, an Indiana University evolutionary biologist and author of the mitochondrial DNA paper.

“There’s not another genome in any organism of any type like this,” added Palmer. “No one has found this scale of horizontal DNA transfer even in a bacterium, where it’s really common. No one has found whole genomes, much less four of them, taken up by horizontal transfer.”

A somewhat downtrodden bottom-dweller of the South Pacific tropics, A. trichopoda hosts a bevy of algae, moss and other hitchhiking plants, some of them parasitic. In that rough-and-tumble world, tears and wounds likely exposed the plant to foreign mitochondria, which then fused with its own mitochondria - organelle sex.

“In some real sense we should regard mitochondria to be engaging in a kind of sex, just like nuclear genomes do,” he said.

The plant’s mitochondria thus retain a kind of fossil record largely absent in other plant species. The foreign DNA amounts to about six genomes, the researchers believe — at least four of them acquired in whole.

Text Only
World, nation, state
  • Plan to simplify 2015 health renewals may backfire

    If you have health insurance on your job, you probably don’t give much thought to each year’s renewal. But make the same assumption in one of the new health law plans, and it could lead to costly surprises.

    July 28, 2014

  • Hospital shooting suspect charged with murder

    A man accused of fatally shooting his caseworker and grazing his psychiatrist at a suburban Philadelphia hospital complex before the doctor returned fire has been charged with murder.

    July 28, 2014

  • Man seeks video of Oklahoma City bombing

    One man’s quest to explain his brother’s mysterious jail cell death 19 years ago has rekindled long-dormant questions about whether others were involved in the 1995 Oklahoma City bombing.

    July 28, 2014

  • Bill in Congress to help veterans with PTSD

    A group of lawmakers have joined together to help veterans with Post Traumatic Stress Disorder (PTSD), Post Traumatic Brain Injury (PTBI) and other war injuries get speedy medical treatment — and avoid Veteran’s Administration bureaucracy and Department of Defense lack of accountability.

    July 28, 2014

  • U.S.: Russia has fired rockets into Ukraine

    Stepping up pressure on Moscow, the U.S. on Sunday released satellite images it says show that rockets have been fired from Russia into neighboring eastern Ukraine and that heavy artillery for separatists also has crossed the border.

    July 28, 2014

  • U.S. says Russia is firing across border into Ukraine

    Russia is launching artillery attacks from its soil on Ukrainian troops and preparing to move heavier weaponry across the border, the U.S. and Ukraine charged Friday in what appeared to be an ominous escalation of the crisis.

    July 25, 2014

  • Gaza sides agree to lull but truce efforts stall

     Israel-Hamas fighting looked headed for escalation after U.S. Secretary of State John Kerry failed Friday to broker a weeklong truce as a first step toward a broader deal and Israel’s defense minister warned Israel might soon expand its Gaza ground operation “significantly.”

    July 25, 2014

  • Planes with Ukraine bodies arrive in Netherlands

    Two more military aircraft carrying remains of victims from the Malaysian plane disaster arrived in the Netherlands on Thursday, while Australian and Dutch diplomats joined to promote a plan for a U.N. team to secure the crash site which has been controlled by pro-Russian rebels.

    July 24, 2014

  • UN school in Gaza caught in cross-fire; 15 killed

    A U.N. school in Gaza crowded with hundreds of Palestinians seeking refuge from fierce fighting came under fire Thursday, killing at least 15 civilians and leaving a sad tableau of blood-spattered pillows, blankets and children’s clothing scattered in the courtyard.

    July 24, 2014

  • Air Algerie jet with 116 on board crashes in Mali

    An Air Algerie jetliner carrying 116 people crashed Thursday in a rainstorm over restive Mali, and its wreckage was found near the border of neighboring Burkina Faso — the third major international aviation disaster in a week.

    July 24, 2014

House Ads

Click HERE to read all your Parade favorites including Hollywood Wire, Celebrity interviews and photo galleries, Food recipes and cooking tips, Games and lots more.
AP Video