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

The Scent of Jealousy! Interview with Meghan Laturney on mate-guarding behavior!!

You know of Hollywood plots where a man comes smelling of another woman, and his wife suspects him of cheating on her. The woman is relying on olfactory cues for keeping a tab on the guy's sexual behavior. Does this soap-opera behavior also occur in other species? Is smell used as a tool to guard against promiscuous behavior??

Meghan and her colleagues try to tease apart such behavior in the fruit fly, Drosophila melanogaster. They see that the male deposits specific scents on the female's body and inside her reproductive tract. Both these olfactory cues decrease the female's attractiveness to future mating partners. This increases the chances of the male's sperm fertilizing the female. The female, on the other hand, might actively try to remove these marking scent in order to continuing mating, which gives her eggs better to survive. To know more about this exciting arms race between the sexes, please listen to Meghan!


To know more on the topic, please refer to:
Drosophila melanogaster females restore their attractiveness after mating by removing male anti-aphrodisiac pheromones.
Laturney & Billeter. Nature Communications.  7, 12322 (2016)

What did you have for dinner last night? Interview with Vishnu Sreekumar on memory formation in the real world!

Isn't is difficult to remember what you had for dinner two night ago, but so easy to remember your first kiss! Why is it difficult to remember few experiences while other stay etched in our memory forever. Of course, we have limited brain capacity, so few things are removed at the expense of others, but how do we evaluate that information; how much decision making goes into paying attention to important tasks for remembering them later onward.

Vishnu Sreekumar and his team work on memory formation in the real world. They utilize information gathering using contemporary technologies to come-up with models that can explain what we look for in experiences when memories are being formed. Their exciting work not only helps model our day-to-day working, but can also help people with better memory retention and improving attention span. To know more, please listen to Vishnu.


For further information please refer to the following publication:
The Episodic Nature of Experience: A Dynamical Systems Analysis.
Sreekumar et al., Cognitive Science, 23 July 2016.

Piggyback Microbe and Cancer! Interview with Niranjan Nagarajan on role of microbiome in bile duct cancer.

Cancer is a very complex disease, with various genetic and environmental factors playing a role in its development and growth. Mutations within the cell and signaling among cells is well known to play vital roles. But could there be other players involved in the process. Of note, something which surrounds us at all times: our microbiome?

Our body is composed of as many microbiome as our own cells. A lot of it comes from the food we eat and the water we drink. Along with our meals, food related parasites might bring their own microbiome into our body, and these could in turn home into organs and modify the tissue microenviroment. This is what Niranjan and colleagues see for bile duct cancer - in which liver fluke parasite arriving from consumption of raw fish finds a home in the bile duct and increases the chance of developing cancer. Their work emphasizes an appreciation into the role of microbiota in cancer development. To know more, please listen to Niranjan.  



To learn more, please refer to:
Tissue Microbiome Profiling Identifies an Enrichment of Specific Enteric Bacteria in Opisthorchis viverrini Associated Cholangiocarcinoma
Chng et al., eBioMedicine, June 2016Volume 8, Pages 195–202.