We spent two days at the Arthropod Genome Symposium at the University of Illinois in Urbana-Champaign. The photo shows PI Wolfgang Stein, MS students Casey Gahrs and Abbi Benson, and Julian Gutekunst, PhD in Frank Lyko's lab, our collaborator at the German Cancer Research Center.

Abbi Benson won the outstanding MS student teaching award. Only one award is given out each year in these categories.

The lab presented two posters and one oral seminar at this year's Phi Sigma Research Symposium. Casey Gahrs and Abbi Benson presented their posters on marbled crayfish molecular neuroscience, and Margaret DeMaegd presented a seminar on modulation of sensory neuron activity.

Our lab went to Illinois State University child care last week and introduced our lab animals to the kids. MS students Casey Gahrs, Abbi Benson and PhD student Margaret DeMaegd told crayfish and crab stories and answered questions.
Our favorites were: "Do crabs have tails?", "Do crayfish die if they live on land?" and of course "Do you dress them up in clothes? " :-)

Our lab presented three posters at the local University Research Symposium. The photo below shows MS students Casey Gährs, Abbi Benson, PhD student Margaret DeMaegd and PI Wolfgang Stein next to their posters.

Our marbled crayfish genome paper is out. Congrats to our collaborators for making this such a nice story!

In this study we sequenced the genome of a parthenogenetic species of crayfish, called the marbled crayfish (Procambarus virginalis). Parthenogenetic means that these animals reproduce asexually - the whole species is female. More interestingly, the creation of the species happened only about 25 - 30 years ago. It is the youngest parthenogenic species known.
While we do not know how it exactly happened, but at that time, a slough crayfish (Procambarus fallax) couple mated and something went wrong. One (and only one) of their daughters inherited an additional set of chromosomes. That daughter could no longer reproduce normally, but instead was able to generate live offspring without males.
Slough crayfish live in Georgia, but that one special animal was introduced to German pet trade in the mid nineties. Our study shows that all worldwide existing animals of that species stem from that one animal, and was likely distributed worldwide by pet trade.
We sequenced several individuals of this species (one of them here at Illinois State University, several others by or collaborators in Germany). This is the first decapod crustacean to have its genome and transcriptome sequenced and published. Decapod crustaceans are lobsters, crabs, and crayfish. Their genome is larger than the human genome, and has about the same number of genes. Surprisingly, we find that there is very little genetic variability - these animals are all clones of one another. Once a mother lays an egg that egg is a perfect clone of the mother. One part of the study was to track how this species expands, and whether its genome adapts to differences in the environment as it does so. That does not seem to be the case.
Nevertheless, these animals are extremely invasive and successful in the wild. In the example on Madagascar we studied, they spread in less than 10 years from 400 square miles to 40,000 square miles - an increase by 100 fold. That is from about the size of half of Rhode Island to almost the size of Ohio in 10 years. This is very surprising because we usually think of competitive species being genetically rather diverse to be able to cope with changes in the environment. One reason could be their quick reproduction rate of several hundred offspring in about 3 months.

What are our own interests in this species? I am a Neuroscientist and interested in how nervous systems deal with environmental influences. One of the hypotheses that is out there is that species maintain a certain level of diversity in their brain cells and circuits to - as a species - respond best to changes in the environment such as for example temperature. The marbled crayfish seems to defy that idea, which makes it a perfect study organism.
The nervous system of decapod crustaceans has several advantages for studying the physiology of neurons, including the large size and small number of nerve cells. Nevertheless, findings can be generalized and are applicable also for larger animals, such as mammals. Having the genome and transcriptome of the marbled crayfish available will now also allow us to create transgenic animals to manipulate gene expression in the nervous system of this species, adding another exciting technique for studying neurons and their physiology.

Here is my interview with Ira Flatow, the host of Science Friday:
https://www.sciencefriday.com/segments/the-genetic-mystery-of-the-invasive-crayfish-clones/

Here is an interview with CBC, the Canadian Broadcasting Company:
http://www.cbc.ca/radio/asithappens/as-it-happens-tuesday-edition-1.4522534/they-re-coming-mutant-all-female-crayfish-are-cloning-themselves-at-an-incredible-rate-1.4522555

The Stein lab is looking for new graduate students to join our lab. We are particularly interested in students with a keen interest in using neurophysiology and optical imaging to study sensory processing, motor control and robustness of neural activity in a well-characterized invertebrate system.

Our lab also organized the Neuroethology/Inverterbrate Neuroscience Social, which was (again) a great success. We had more than 100 attendants, including students, postdocs and faculty.