A brief interview with Dr. Mar Martinez Pastor
Dr. Mar Martinez Pastor is a microbiologist from Valencia, who currently works as a senior Research Scientist in the Schmid Lab (leader Dr. Amy Schmid) at Duke University. She is a specialist in microbial response to abiotic stress. At the Schmid lab her research is focused on the transcriptional regulation of iron homeostasis in halophilic archaea.
Halophilic archaea are salt-loving archaea, which can be found in hypersaline environments like the colorful salt pond pictured above in San Francisco Bay, California. Because halophilic archaea thrive in environments of extreme pH, temperature and salinity they are considered extremophiles. As the name suggests, studying how they cope under extreme conditions can also be extremely tricky and never boring.
In hypersaline environments iron availability can rapidly fluctuate. Thus, how different species of halophilic archaea control iron homeostasis relies on the role of certain transcription factors from the DtxR family that regulate the expression of hundreds of genes to facilitate the adaptation (Martinez-Pastor et al., 2017). To have an insight of the archaeal transcriptome changes as a consequence of the stress response, proper sequence coverage of mRNA is necessary. However, in prokaryotes the high rRNA:mRNA content (80-90% : ~10%) has been an obstacle in obtaining the desired information about the mRNA sequences.
In her latest article, Dr. Martinez compares and tests the efficiency of rRNA removal kits in the hopes of obtaining the “cleanest” mRNA sequences. Her results show the ribosome depletion kit from siTOOLs Biotech: Pan-Archaea riboPOOL was able to efficiently deplete >90 % of rRNA among Halobacterium salinarum (pictured left, image provided by Dr. Martinez), Haloferax mediterranei and Haloarcula hispanica. Likewise, the custom-design riboPOOL for the species Haloferax volcanii was highly successful in rRNA depletion (Martinez Pastor et al., 2022).
In conclusion, we could say it’s the ideal time to study transcriptomics in extremophiles like salt-loving archaea. ??
Our Pan-Archaea riboPOOLs are ready, efficient and pleased to help “break” through the bottleneck in the study of genome-scale gene expression in archaea. We can’t wait to read what Dr. Martinez and her colleagues will find out next.
Lastly, besides learning about Dr. Martinez research we wanted to know more about her journey in science, her hobbies and what she enjoys. So here it goes:
Six questions for Mar (which means sea in Spanish):
1. What is the most interesting part of studying archaea?
Archaea are ancient microorganisms that colonize all kind of environments, from the most common to the weirdest. By shape and structure, they look like bacteria; however, there are some other features as the transcriptional machinery, that resembles to a simpler version of Eukaryotes. And even more, other traits make them to be unique (as their cell membrane structure). Using Archaea as a model organism makes me feel that I am studying the midpoint of life, and any discovery could be pointing in any direction, could explain evolution and adaptation, could be giving us insight from the past and lightening the future!
2. What is the most challenging part of studying iron homeostasis in halophilic archaeal species?
There is not a “starting point”! I started my scientific career investigating with the yeast Saccharomyces cerevisiae as a model organism, and every hypothesis was based on the bibliography, however, working with iron imbalance adaptation in Archaea I realized that different species, even those that are closely related, behave differently in response to iron stress! Also, I had to face many experiments that weren’t previously described in the bibliography (as for siderophore detection or for using kits as riboPOOLs for the first time!)
3. What drew you to study iron homeostasis?
I have been always curious to know more about how cells respond to abiotic stress. I am so thrilled to unravel the mechanism by which cells detect a change in the environment and trigger an adaptative response.
4. How important is it to have a mentor, and what advice do you give young scientist which are part of a lab that is not as supportive?
I was very lucky to join the Schmid lab. Dr. Schmid provides all the tools to learn science from different sides (wet biology, system biology, bioinformatics…), she is supportive and gives us plenty of opportunities to teach, to present our work in conferences and meetings, to attend courses and complement our formation, in summary, to grow as a complete scientist. Young scientists have more needs beyond learning technics. A mentor should be a model. My advice for young scientist is to learn as much as they can from their current mentor, but if this is not enough, to rush looking for the next one to learn from.
5. What would you do if you had more time?
In lab, long term experiments: growing cells for longer periods in changing conditions and check what transcriptional mechanisms they use to adapt. In life, I would like to get back to activities that I abandoned, or I do now with limited time. I would like to read novels, walk the dog or go swimming without thinking that every single minute that I am spending on a hobby is stolen from a “more important” activity!
6. Which is your favorite place in the world?
Featured image: Salt ponds with pink colored Haloarchaea on the edge of San Francisco Bay, California; photo by Kenneth Lu, 2013 available through Flickr.