It's an emergency! Interview with Gesa Zander on cellular response to heat stress!

Imagine a sudden crisis within a country. One day, suddenly, there is a need to face an impending disaster. What happens? The people go into panic-mode and stop doing their regular jobs, and instead focus on averting the crisis. Normal production ceases, and things needed to face the disaster are produced. The pace of production is ramped, and irrespective of the quality, a huge quantity of emergency supplies is generated.

Like humans, cells in our body also face crisis. They need to adapt to extreme environments quickly in order to survive and thrive. Gesa, Alexandra, Lysann and colleagues wanted to know what happens to the cellular production process during the stress period. How does the cell switch to producing cell-responsive genes. And not only producing, but producing at a fast-pace. Are the quality controls applicable during normal times also applicable during the frantic response to stress. They find that the cell switches to stress-control mode, and for a certain time, eases on the quality controls of production. Please listen to Gesa on the interesting adaptability of the cells.


For more information, please refer to:
mRNA quality control is bypassed for immediate export of stress-responsive transcripts
Zander et al., Nature, 2016

A Time to Spring! Interview with Julia Qüesta on cold sensation in plants!!

Winter ends and the layer of snow clears off the ground. The soil is fresh for new cycle of vegetation. It instantly converts to a beautiful expanse of flowers and fresh plants. How does such a drastic change occur? How did the plants 'know' the change in seasons. They don't have an almanac or the weather channel to tell them of the ending cold, or do they??

Julia and colleagues undertook to understand the sensing of winter-to-spring transformation in plants. It is possibly the most important decision for the survival of the plant. Arising anew from winter needs to be perfectly timed. A little early, and the frosty cold will chill the new life. A little late and the other plants would have taken away precious space and resources, making it difficult to fight for survival. And importantly, its a one time event: an on-off switch. The plant needs to integrate a million parameters into a single result. An elaborate chain of events culminating into a life or death choice.

How does the switch operate? Julia and colleagues map the system to basepair resolution by finding the machinery and its corresponding binding sites on the plant genome for controlling the process. This amazing feat (for plant and the team) is a perfect example of how simplicity underlies complex decision making. To understand more, please listen to Julia.



To know more, please refer to:
Arabidopsis transcriptional repressor VAL1 triggers Polycomb silencing at FLC during vernalization.
Qüesta et al., Science 2016.

Colonizing Mars! Lessons on avoiding inbreeding issues from flatworms by Longhua Guo!

Imagine the year 2500. We have chosen twenty of our best and brightest to send to Mars. They have the mission to start a human colony there. Of-course that would mean breeding and generating more humans. But with only 20 people, the population might be genetically too small. Creating babies from genetically similar individuals, like cousins, can lead to birth defects. Within a few populations, intermixing might doom the entire project, just like inbreeding doomed the once powerful Habsburg Dynasty. How can we avoid this?

The question is not only critical to our hypothetical journey to Mars, but also to survival of critically endangered species. Very few individuals of hawksbill turtle, tigers and many other remain. How can we avoid in-breeding defects in such animals in near future. The answer to that might lie in the champions of regeneration, freshwater planarians. Planarians are known for their amazing capacity to regenerate a full animal from any part of their body. But also, as Longhua and colleagues found out, can avoid their genome from becoming similar after multiple rounds of in-breeding. How can these animals achieve such feat, please listen to Longhua to know more:


For more information, please refer to:
Widespread maintenance of genome heterozygosity in Schmidtea mediterranea.
Guo L., et al., Nature Ecology & Evolution, 2016.

Further information can be found here:
The joy of figuring things out: a story of worms, haplotypes & genetic ancestry.

No man left behind! Interview with Judith Yanowitz on faithful DNA segregation during meiosis.

DNA is the strand that connects generations of life. It contains the information needed for all phases of life, and that information needs to be faithfully passed on to the off-springs for the specie to continue. In multiple organisms, this information is divided into chromosomes, and each of these chromosomes need to be copied and separated equally during germ cell formation. Any disturbance in the logistics of chromosome separation can leave one of the two daughter cells with less or more material, which can be detrimental.

How does the cell ensure proper logistics during the process? How does it know when the separation process has started and when each and every chromosome has been successfully separated? It's not a simple counting process since the number of chromosome differs between species, with humans having 23 sets, but our close relatives, chimpanzees and ape have 24 pairs. How does the cell adapt to this diversity. Tyler, Rana, Judith and colleagues ask this question and find a very interesting mechanism guiding the process. They find a surveillance mechanism that starts as soon as the first chromosome starts information exchange, and lasts until the last one finishes, thereby ensuring that the process only proceed after its faithful completion. To understand the details, please listen to the interview with Judith.


To know more about the work, please read the following article:
A Surveillance System Ensures Crossover Formation in C. elegans
Tyler and Rana et al., Current Biology, 2016

Food for Eye! Interview with Tiago Santos-Ferreira on cell-support paradigm for retinal transplantation!

Cell-transplantation based therapy is increasingly becoming relevant these days, esp. with a bloom in techniques for stem cell and organoid production. The transplanted cells could greatly benefit treatment of degenerative diseases. But how do the transplants help the diseased organ. The obvious thinking is that they help by providing a fresh supply of healthy cells. But is that always the case?

Tiago and colleagues asked what happens to retinal cells transplanted into a damaged eye. And surprisingly found that the transplanted cells did not integrate into the organ, but rather provided cytoplasmic material to the pre-exisiting host cells. Cytoplasmic material present within the transplanted cells was being taken up by the host cells. This was a clear indication of a new way by which transplants could help the damaged tissue, which could be used to potentially transfer much more cargo in future. To know more, please listen to Tiago.  


For further information, please refer to:
Retinal transplantation of photoreceptors results in donor–host cytoplasmic exchange.
Santos-Ferreira et al., Nature Communications, 2016

Packaging without packets! Interview with Shamba Saha on membrane-less organization within cells!!

How do you organize your stuff at home. In boxes, I suppose. Tucked into boxes, all the stuff is nicely arranged. This is not special to human behavior, as even biological cells use the same principle of compartmentalization! They organize the information source (DNA) into nucleus, making it efficient to read and copy. They put all energy forming apparatus into units called mitochondria. They organize garbage disposal into chambers called lysosomes. But the beauty and complexity of biological systems doesn't stop there! They go one step further and aggregate developmentally important and dynamic stuff into structures that lack a membranous boundary; essentially packaging biological entities without an overt packet!

How do they achieve such a feat. Shamba and colleagues try to answer this question by looking at the formation of germline defining particles, the P-bodies, in a worm, C. elegans. These non-membranous compartment, they find, are generated by an striking process called phase-separation, just like oil droplets form when mixed with water! But these bodies are much more than passive emulsions, and are a complex mix of RNA and protein dynamically interacting with the surroundings!! What is even more striking, and beautiful, is that these do not form randomly, but are localized to one area of the cell. How many components are needed to make such a complex biological process?? Listen to Shamba to know that the real beauty in the system is its simplicity, as only one (ONE!!!) protein is enough to generate these structures, and a very small network to regulate it.



To know more about the work, please refer to the following publication:
Polar Positioning of Phase-Separated Liquid Compartments in Cells Regulated by an mRNA Competition Mechanism
Saha et al., Cell. Volume 166, Issue 6, p1572–1584.

Also, you can see a video abstract on the topic here:
Phase separation in cell polarity
  

A morphing traveler. Interview with Mohit Jolly on identity changes during metastasis!

Cancer cells evade foreign tissues during metastasis. This process is most critical phase of cancer development, since it decreases a successful prognostics drastically. During the invasion process, the cells change their characteristics, acquiring different shapes, cell identity and lineage. How this is regulated still remains open question, and vital to developing a cure for the disease.

Mohit and colleagues take an integrated theoretical-experimental approach to understand how sarcomas spread. Sacromas arise from connective tissues, like bone or fat. And while traveling long distances they undergo a change into more epithelial like identity. This plasticity helps the cells survive better in the the body. To more more about such transition, please listen to the interview with Mohit.



For more information, please refer to:
Mesenchymal-epithelial transition in sarcomas is controlled by the combinatorial expression of miR-200s and GRHL2
Somarelli et al., Molecular and Cellular Biology, 2016