New Discoveries In March

In this month, scientists in Singapore achieved a bumper crop of notable discoveries. Fresh Brainz highlights three of them:

1. New genes involved in Alzheimer's Disease

Alzheimer's Disease is a debilitating neurodegenerative disorder that mainly strikes the elderly, gradually destroying their memory abilities. Amyloid plaque deposits that disrupt brain function is a key feature of this disease.

But why would the brain produce such a harmful substance? A team of scientists from IMCB and NUS have discovered that this plaque is actually a by-product of the normal brain cell regeneration process. They have also identified two genes that are involved in this pathway, TAG1 and Fe65. This is an important finding because drug companies can now focus on these genes to reduce the plaque production.

Original paper: A TAG1-APP signalling pathway through Fe65 negatively modulates neurogenesis (Nat Cell Bio)

2. New core circuitry in embryonic stem cells

Previous work by other researchers have shown that a gene called Klf4 is important for reprogramming somatic cells in order to give them stem cell properties.

However, Klf4 is dispensible in the self-renewal and pluripotency of embryonic stem cells. How can this be?

Scientists from the GIS discovered that the reason is due to the redundant function of other members of the Klf family. If Klf2, Klf4 and Klf5 are simultaneously depleted, the stem cells will differentiate. They uncover the importance of the core Klf circuit to the properties of embryonic stem cells.

Original paper: A core Klf circuitry regulates self-renewal of embryonic stem cells (Nat Cell Bio)

3. Biodiversity of phages

Viruses that infect bacteria are called phages. Since they appeared in the fossil record 3.5 billion years ago, some phages have been living in viral communities in organosedimentary structures, also known as microbialites.

Using a comparative metagenomics approach, a team of scientists from the USA and Singapore have discovered that phages in modern microbialites are not only different from each other, but also different from phages in any other ecosystem so far.

The evolutionary significance of this finding is that modern microbialites are the remnants of ancient ecosystems. The technological significance is that this is the first large-scale use of DNA sequencing technology to discover unknown viruses in various environments that can impact human health.

Original papers: Biodiversity and biogeography of phages in modern stromatolites and thrombolites (Nature) , Functional metagenomic profiling of nine biomes (Nature)