Science Roundup

Rcjohnsen rcjohnsen at
Wed Dec 27 23:16:25 EST 2000

Welcome to the latest issue of Science Roundup, sponsored by 
InforMax, Inc.

PLEASE NOTE: There are links throughout Science Roundup to 
articles on *Science Online* (  You 
must be a subscriber to *Science Online* to read the full text of the 
articles.  Abstracts, however, are available free of charge.
"Someone with a subscription may help you obtain an article copy."
First, a very quick word from our sponsor:

InforMax Inc. expands their desktop software product line with the 
release of Vector NTI Enterprise, a robust shared database 
connectivity tool providing a secure, integrated environment for 
data analysis and management. See details below.

Contents of this Issue:

Breakthrough of the Year: Genomes
Wild about the Weed (Arabidopsis genome)
Moving Ahead, Cautiously, in Stem Cell Research
News from Out There (planetary science and astrophysics)
The Science of the Very Small (nanotechnology)
Another Look at Vision Development
Memory, Amnesia, and . . . Tetris?
Malaria's Deadly Challenge
Progress in Cellular Immunology
Looking Back at the Younger Dryas
Winding Up the "Pathways" Journey
Exploring the Roots of Disease
Cholesterol's Ins and Outs
An RNA Precursor?
Special Issue: Dendrites

In the fourth quarter of 2000, *Science* brought readers insights 
on stem cells, gamma ray bursts, nanomotors, and Parkinson's 
disease -- as well as a roundup of the big research breakthroughs 
(and pitfalls) of 2000.  Here are some of the highlights of the past 
three months.

Breakthrough of the Year: Genomes

*Science* ended 2000 with its annual review, "Breakthrough of 
the Year" (22 Dec. 2000) -- and, though it's always tough to select 
among many compelling scientific accomplishments, this year one 
area seemed to stand out: genomes.  The online publication of 
huge volumes of genome data, the announcement of a finished 
draft of the human genome, landmark papers on *Drosophila* and 
*Arabidopsis*, the emergence of microarray technology for study 
of gene expression and proteomics: All have the potential to 
reshape biomedicine, and place humankind on some ethical *terra 
incognita*, in the coming century


--the extraordinary revelations on the function of the cell's protein 
factory, the ribosome, published in *Science*, *Nature*, and 
*Cell* during 2000;

--a spectacular Eurasian fossil find that provided the first 
undisputed evidence that humans left Africa at least 1.7 million 
years ago;

--advances in the use of plastics and other organics in electronic 
and laser applications;

--further progress in stem cells and cloning;

--evidence for the importance of water on and Mars and Europa; and

--new observations in cosmology, cellular receptors, planetary 
geology, and "quantum weirdness."

Rounding out the presentation were predictions of top stories for 
an assessment of *Science*'s year-end 1999 predictions for 2000 
a review of the Wen Ho Lee snafu 
tagged the "Meltdown of the Year"; and a discussion of the 
"Controversy of the Year," the debate surrounding biomedical 
research ethics 

In keeping with genomics as 2000's Breakthrough of the Year, 
*Science Online* launched a new feature, the *Science* 
Functional Genomics Web Site, with links to news, research, and 
resources for genomic and post-genomic science and the biotech 
business (

Wild about the Weed

One notable event in genome-studies history took place near the 
end of 2000, when the first complete plant genome sequence -- that 
of the mustard weed, *Arabidopsis thaliana* -- was published in 
*Nature*.  *Science* marked the occasion in its 15 Dec. 2000 
issue with news, commentary, and research on this crucial model 
organism.  News stories reviewed the effort to sequence the weed's 
complex genome, the plant's importance not only in molecular 
biology but also in ecological and evolutionary studies, and the 
insights the sequencing process has allowed on the mysterious 
chromosomal structures known as centromeres 
An editorial by Caroline Dean 
noted the potential for plant science inherent in the *Arabidopsis* 
sequence -- and also the need to balance future funding between 
understanding the mustard weed and sequencing other plant 
genomes.  A Policy Forum by C. Somerville and J. Dangl 
overviewed the "2010 Project," an ambitious program with the 
goal of knowing the function of all plant genes within ten years.  
And a trio of research articles drawing on the new data explored 
the comparative genomics 
gene expression 
and molecular evolution 
of *Arabidopsis*.

Moving Ahead, Cautiously, in Stem Cell Research

Even as it noted the extraordinary progress in genomics, *Science* 
continued to publish groundbreaking work in the area cited as 
Breakthrough of the Year for 1999: stem cell research.  In the
1 Dec. 2000 issue, reports by Brazelton et al. 
and Mezey et al. 
independently showed that cells from bone marrow transplanted 
into genetically altered mice can migrate to the brain.  Most 
remarkable, however, a small percentage of migrated cells (tagged 
using expression of a green fluorescent protein in one case and a 
genetic marker in the other), once they reached the brain area, were 
found to express proteins characteristic of neurons -- a sign that 
bone marrow had, in effect, become brain.  A News Focus by 
Gretchen Vogel 
examines the implications of these discoveries in detail, and the 
larger ethical debate on research using stem cells from human 

News from Out There

During the 2000 fourth quarter, new insights emerged in the pages 
of *Science* into planetary geology and astrophysics, covering 
settings ranging from Earth's near neighborhood to the edges of 
the observable universe:

-- Brown et al. (13 Oct. 2000; 
presented the first detailed scientific discussion of the Tagish Lake 
meteorite.  The presence of scores of eyewitnesses (coupled with 
the serendipitous collection of the meteorite by a local resident, 
who carefully preserved the specimen in his freezer) allowed a 
thorough treatment of the probable orbit, pre-atmospheric mass, 
and composition of an extremely primitive meteorite -- one that, as 
J. N. Grossman writes in an accompanying Perspective 
could prove to be the most important recovered fall since the 
Allende and Murchison events three decades ago.

-- A study of isotopic ages for impact melts in lunar meteorites by 
Cohen et al. (1 Dec. 2000; 
suggests that the moon underwent six to ten major impact events 
between 2.76 and 3.92 billion years ago, and thus provided new 
evidence for the "lunar cataclysm hypothesis" -- the idea that 
large-scale impacts early in its history resurfaced much of the 
moon and created the prominent lunar basins.  The pulse of activity 
on the moon, as noted in a News Focus in the same issue 
suggests an even more wrenching bombardment on the Earth, with 
profound implications for the origin and early evolution of life.

-- The possible importance of water in early martian history (with 
all of its implications for the possibility that life once existed on 
the Red Planet) received another boost in the 8 Dec. 2000 issue 
Malin and Edgett offered a series of impressive high-resolution 
images from the Mars Global Surveyor spacecraft that include 
huge, layered outcrops -- which, the authors argued, could 
represent stands of sedimentary rock originally laid down in lakes 
and shallow seas that formed in the crater-swept martian landscape 
billions of years ago.

-- On 6 Oct. 2000, Zapatero Osorio et al. 
reported that, using optical and near-infrared imaging and 
spectroscopy, they had determined that several objects of five to 
fifteen Jupiter masses in a star cluster near the sigma-Orionis were 
too cool to be stars, and thus might be planets.  The kicker: If so, 
these would be "planets without orbits" -- unassociated with a 
particular star, and floating freely within the cluster.  A news 
highlighted the controversy stoked by the finding.

-- Finally, looking out to the edges of the observable universe, 
papers by Amati et al. 
( and 
Piro et al. 
( in 
the 3 Nov. 2000 issue provided new glimpses into one of the 
universe's most violent events: gamma ray bursts, which produce 
more energy in a second than an average star will throw off in 10 
billion years, and which are generally thought to stem from the 
collapse of a supermassive star into a black hole.  As discussed in 
an accompanying news feature 
(, the 
observations point to a revised hypernova model in which the 
supermassive star collapses not once, but *twice*.

The Science of the Very Small

*Science* also zoomed in on the efforts of researchers studying 
affairs at very small length and time scales.  A special section, 
"Issues in Nanotechnology" (24 Nov. 2000;,
reviewed the investigations of scientists in the diminutive world 
of nanometer-scale electromechanical systems, fabricated 
materials, and other devices reaching down to the molecular scale.  
Also during the quarter, *Science* published pathbreaking 
research on nano-world observations and developments, including:  
a new method for making extremely strong carbon nanotube fibers 
so plastic they can actually be tied into knots (17 Nov. 2000;; 
surprising, near-molecular-scale observations of the process of 
surface alloying -- characterized in a companion Perspective as 
"direct observation of a nanomotor" (24 Nov. 2000;, and 
with a nifty set of online movies 
and imaging of magnetic precession at nanometer spatial and 
picosecond temporal resolution (20 Oct. 2000;, 
with the presentation again supplemented by a striking video clip 
on *Science Online* 

Another Look at Vision Development

For more than 30 years, it's been a core premise underlying studies 
of vision development: the structures in the brain's visual cortex 
that respond to stimulation from one eye or the other -- known as 
ocular dominance columns -- are not pre-existent neural "tracks," 
but form and are shaped in response visual activity.  But a study in 
the 17 Nov. 2000 threw down the gauntlet against that widely held 
view.  Crowley and Katz 
examining ocular dominance columns in ferrets at various stages 
of development, found that the columns were well established even 
in adults that had had all visual stimulation cut off at birth -- an 
indication that retinal activity is less important in shaping the 
formation of these crucial neural structures than previously 
thought.  An accompanying news article 
reviewed the controversial finding and the questions that it raises.

Memory, Amnesia, and . . . Tetris?

Exploring the nature of memory sometimes entails enlisting some 
unusual tools.  In a fascinating study published in the 13 Oct. 2000 
*Science*, Stickgold et al. 
employed the computer game Tetris, whose rotating, falling 
geometrical blocks are familiar to overworked grad students 
everywhere.  In the study, both normal subjects and amnesiacs -- 
patients with damage to the brain's hippocampal region that 
prevented them from building new stored, or "declarative," 
memories -- were taught the game in intensive sessions during the 
day, and then were awakened that night during their initial, light 
sleep and asked what sensations they had experienced during the 
sleep period.  Most of the normal subjects reported seeing images 
like the shapes of the falling Tetris blocks.  More surprising, the 
amnesiacs reported seeing the same shapes -- even though they had 
no recollection of playing the game at all.  The study suggests new 
insights on how the brain converts transient perceptual memories 
into stored declarative memories.

Malaria's Deadly Challenge

Malaria kills between one and three million persons per year -- a 
death toll greater than that of any infectious disease except AIDS 
and tuberculosis.  Yet, until recently, the broad scientific research 
and funding communities showed less interest in understanding 
and fighting the deadly malarial pathogen *Plasmodium 
falciparum* than those grim numbers would suggest.  After 
decades of neglect, however, the fight against malaria is moving to 
the front ranks of the world's scientific problems, as international 
funding and aid organizations are now pouring money into malaria 
studies.  A special news focus (20 Oct. 2000; 
examined the forces reinvigorating the fight against malaria -- and 
how studies of the genome of *P. falciparum* and its main vector, 
the *Anopheles* mosquito, could lead to new treatment and 
prevention strategies.  A month later, in the 20 Nov. 2000 issue, a 
set of Policy Forums 
m) debated the pro's and con's of emphasizing genomics as a tool 
in the battle against malaria.

Progress in Cellular Immunology

The "rich and diverse army" of immune-system cells that has 
evolved over billions of years formed the subject of the fourth 
quarter's first Special Issue of *Science* (6 Oct. 2000;
News stories focused on how two different cutting-edge 
technologies -- computer modeling and microarrays -- are shedding 
light on the workings of cellular immunology.  And Review and 
Viewpoint articles covered some of the scientific frontiers of 
cellular immunology, overviewing recent research on inhibitory 
receptors, the relationship between B cells and T cells, the 
dynamics of T cell responses and T cell memory, and how the 
immune system handles pathogenic invasions at surfaces such as 
the skin and the mucous membranes. 

Looking Back at the Younger Dryas

For paleoclimatologists, one of the most argued-about Holocene 
events is the cooling around thirteen millennia ago known as the 
Younger Dryas (named for the sudden reappearance in the 
Scandinavian fossil record of *Dryas octopetala*, a cold-tolerant 
flower).  The event, a thousand-year interruption in the warming 
that led to Holocene deglaciation, has been documented in North 
Atlantic marine and ice cores -- but was the Younger Dryas limited 
to the Northern Hemisphere, or was it a global phenomenon?  
Bennett et al. (13 Oct. 2000; 
offered data that strongly support the former view.  Studying fossil 
pollen in radiocarbon-dated sediments from four lakes in southern 
Chile, they found evidence only of steady warming in the region, 
and a steady southward-migration of cold-tolerant species, with no 
reversal during the period corresponding to the Younger Dryas (or, 
for that matter, any other time).  D. T. Rodbell discussed the 
findings in an accompanying Perspective 
A 22 Dec. 2000 study of the precipitation history of the Amazon 
basin, by Maslin et al. 
however, points to other Southern Hemisphere changes during the 
Younger Dryas period: the study suggests that the Amazon's 
discharge then dropped to some 60% below modern values -- a dry 
Younger Dryas indeed.

Winding Up the "Pathways" Journey

The climate system also formed the subject of the quarter's first 
essay in "Pathways of Discovery" -- *Science*'s yearlong 
exploration of the history and future of some key scientific 
disciplines.  P. J. Crutzen and V. Ramanathan (13 Oct. 2000; 
looked at the evolution of atmospheric science, from Torricelli's 
invention of the barometer, in the mid-17th century, to 
sophisticated numerical models run on massively parallel 
computers, at the dawn of the 21st.  A month later, E. R. Kandel 
and L. R. Squire (10 Nov. 2000; 
reviewed the incredible development of cellular and molecular 
neuroscience since Ramon y Cajal's advancing of the "neuron 
doctrine" in the early 1900s.  And M. J. Rees (8 Dec. 2000; 
wound up the Pathways journey with a whirlwind tour through 
perhaps the strangest science of all, cosmology: the realm of black 
holes, neutron stars, dark matter, and superstrings.

Exploring the Roots of Disease

The deep structure and potential treatment of celebrated diseases 
were the subject of several fascinating *Science* reports over the 
past three months:

--Orth et al. (24 Nov. 2000; 
illuminated the signal-transduction havoc wrought by one of 
history's most notorious killers, *Yersinia pestis* -- the pathogen 
responsible for the Black Death, which routed Europe and Asia 
during the 14th century.  As is discussed in an accompanying news 
, one of the *Yersina* bacterium's first acts is to inject into the 
body's macrophage cells a protein called YopJ, which in turn rips 
apart the proteins that the macrophage uses to communicate the 
infection's presence to the body's other immune cells.

--The food-borne pathogen *Listeria monocytogenes*, by contrast, 
rather than injecting a disruptive protein to foil the immune 
system, actually enlists the aid of unwitting macrophages in its 
attack, according to research published on 3 Nov. 2000 by Decatur 
and Portnoy 
After being consumed by the macrophage and trapped within an 
interior vacuole for later destruction, *Listeria* uses its own pore-
forming protein, listeriolysin O, to burrow through the vacuole 
wall.  Because of an unusual sequence in the protein molecule, 
however, the pore-forming protein degrades quickly after rupturing 
the vacuole, which allows *Listeria* to take up residence and 
multiply within the macrophage without destroying the host cell -- 
and protected from the body's other immune defenses.

--Kordower et al. 
(, on 
27 Oct. 2000, reported progress in the treatment of another 
scourge: Parkinson's disease, which afflicts some one million 
Americans, as noted in the accompanying Perspective by L. Olson 
The Kordower et al. study was also an advance in gene therapy: In 
two primate models of the disease, the researchers used a lentiviral 
vector to introduce a gene expressing glial cell line-derived growth 
factor (GDNF), which in turn prevented degeneration of dopamine 
neurons, allowed some neuronal regeneration -- and resulted in 
reduced motor defects.

Cholesterol's Ins and Outs

A package of articles on 1 Dec. 2000 explored the state of the art 
in cholesterol studies.  Simons and Ilkonen 
reviewed recent findings in the cell biology of cholesterol, and at 
how a new focus on the cellular processes regulating influx, efflux, 
and synthesis of cholesterol could lead to new progress in 
controlling cholesterol disease.  Berge et al., in a report in the same 
focused on the genetic mutations and associated proteins 
responsible for a rare form of inherited cholesterol disease.  Their 
findings, as noted in a companion Perspective by Allayee et al. 
provide "important insights" into cholesterol trafficking in the 
body -- and also suggest potential targets for drugs to decrease 
serum cholesterol.  Findings released three weeks later on 
Niemann-Pick C disease, an ailment related to faulty cellular 
management of cholesterol, shed additional light on cholesterol 
transport (22 Dec. 2000;

An RNA Precursor?

Just how different was the chemistry of life at the dawn of the 
biotic era?  Schoening et al. (17 Nov. 2000; 
examined the tantalizing possibility that one of the fundamental 
molecules of modern life, ribonucleic acid (RNA) -- the basic 
machine of the protein synthesis on which all life depends -- may 
have been preceded in the "prebiotic soup" by simpler genetic 
materials.  In laboratory experiments, the group synthesized and 
studied an RNA analog based on the tetrose sugar threose, which 
they dubbed "TNA"; what's more, they found that TNA strands 
can form stable double-helices both with each other and with 
strands of RNA and DNA.  The potential importance of this 
finding, as noted in a Perspective by L. Orgel 
is that tetrose sugars like threose, which can be assembled 
directly from two identical two-carbon fragments, would likely 
form more readily in a prebiotic world than pentose sugars like 
ribose, which have a more complex structure.  Thus, in principle, 
TNA is one candidate for "an alternative genetic material for 
primitive life forms" -- though many questions remain.

Special Issue: Dendrites

Dendrites have been called "the brains of the neuron" -- and 
studies of these beautiful and complex, branching structures are 
yielding new insights into the biochemical processes that shape 
thought and memory.  A special issue of *Science* (27 Oct. 2000;
updated readers on recent progress in dendrite research -- 
including a news feature on the role of protein synthesis in dendrite 
function, and reviews on the dynamics of dendrite signaling, 
quantitative models, how the dendrites process information from 
thousands of synapses, and the structural changes and plasticity in 
dendrites that may underlie memory and learning.

A final word from our sponsor:

For work groups requiring simultaneous database access, Vector 
NTI Enterprise in conjunction with Vector NTI Suite provides the 
most comprehensive solution available. Vector NTI Enterprise 
software provides an interface between Vector NTI Suite desktop 
application programs and an Oracle database running on a local 
UNIX server, and features local BLAST search capability. The 
BLAST client and BLAST results viewer, components of Vector 
NTI Suite, work together with Vector NTI Enterprise to query 
sequences and visualize search results in a graphical display.  Data 
is freely transferable between the desktop and Oracle data-bases by 
drag and drop. The shared database can be viewed by the entire 
collaborative team and private subsets created by team members 
for individual use. All data types found in the Vector NTI desktop 
database (DNA, proteins, enzymes, oligos, gel markers, citations, 
and BLAST results) can be saved to the shared database. In 
addition, data can be uploaded using UNIX command line utilities.  

For more information about Vector NTI Enterprise, visit or email sales at

You are currently subscribed to scienceroundup as: RCJOHNSEN at AOL.COM
To unsubscribe send a blank email to
mailto:leave-scienceroundup-13213C at

----------------------- Headers --------------------------------
Return-Path: <bounce-scienceroundup-13213 at>
Received: from ( []) by (v77.31) with ESMTP; Wed, 27 Dec 2000 09:46:16 -0500
Received: from ( []) by (v77.27) with ESMTP; Wed, 27 Dec 2000 09:45:48 -0500
Message-Id: <sa49b95a.022 at>
X-Mailer: Novell GroupWise Internet Agent
Date: Wed, 27 Dec 2000 09:41:32 -0500
From: AAAS Member Services <memuser at>
To: "Science" <scienceroundup at>
Subject: Science Roundup
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: quoted-printable
Content-Disposition: inline
List-Unsubscribe: <mailto:leave-scienceroundup-13213C at>
Reply-To: AAAS Member Services <memuser at>
X-Hosted-By: - The Business Email List Experts

More information about the Ag-forst mailing list