Aggression assays to determine social structure

Aparna and Doaa are conducing 1000 aggression assays to determine which of the 30 nests we sampled are separate monogyne colonies (so they aggress ants from other nests) and which are part of a polydomous, polygyne, super-colony (so they do not aggress each other).

Each assay is video recorded and then aggressive behaviors are noted and scored. These include biding:

and spraying acid:

Here is a video of an assay between two nests that aggress each other (two monogyne nests). Both ants bite each other and one is spraying acid on the other:

And here is a video of ants from two nests that do not aggress each other (which is pretty boring):

These two nests are part of the supercolony.

Isaeli conference season

Our lab participated in the meeting of the Israel Zoological Society (in Jerusalem) and the first ever meeting of the Israeli Society of Evolutionary Biology (ISEB 2019, in Tel Aviv). Pnina gave a talk on reconstructing the evolutionary history of the fire ant social chromosome in ISEB and Eyal gave a talk on mapping genes for chemical communication (our QTL mapping study) in the zoological meeting.

It was especially nice to see the large community of evolutionary biologists in Israel come together for a very impressive conference, with two full days of three high-quality parallel session and five great plenary talks, including the wonderful Dan Graur. Eyal participated in the organization of the conference (check out the amazing website:

On the day of the day of the meeting, a whole show of "שלושה שיודעים" on כאן תרבות radio was dedicated to the conference, to evolutionary science in Israel, and to evolution in general. Eyal, Eran Tauber, and Lilach Hadany interviewed on the show, representing the organizing team. Check it out:

סודן האפל של נמלי הבונקר הפולני

איל סיפר על הנמלים שחיו שנים בבונקר גרעיני נטוש עד שבאו חוקרים פולנים והצילו אותן, וגם חשפו את סודן האפל. ראיון בתוכנית שלושה שיודעים ברדיו כאן תרבות

עוד פרטים על הסיפור ההזוי הזה בכתבה של אסף רונאל בהארץ


QTLs found! there is a genetic basis for nestmate recognition cues

We finally have the results from our genomic mapping of cuticular hydrocarbons (CHC) in Cataglyphis niger, which are known to be the chemical cues used by the ants to recognize their nestmates. We found QTLs (quantitative trait loci), which means that there is a genetic basis for the differences in the CHC profiles of different colonies. This study was conducted primarily by Shani and Besan. Shani conducted the chemical and genetic analyses and Besan did the computational analysis for QTL mapping. In our sampling of monogyne colonies from Bezet Beach we found 117 drones in one nest (i.e. male brothers). Shani analyzed their CHCs by gas chromatography (GC), and sequenced their DNA using RAD-seq (a reduced representation genomics sequencing approach). The GC analysis identified 31 CHCs, and the RAD-seq identified 7769 SNPs. Besan analyzed these data using the programs MultiPoint and MultiQTL, with the guidance of our neighbor Abraham Korol who developed them and is THE expert on genomic mapping. First, Besan constructed a linkage map of the 26 chromosomes of C. niger using MultiPoint. Then she used MultiQTL and found 20 QTLs for eight CHCs (FDR < 10%):

We are now looking into the genes in the genomic regions defined by each QTL, using the new and improved genome assembly for C. niger (Pacbio sequencing via the GAGA Consortium).

Solenopsis antennal transcriptomics paper published

Our paper is online at Ecology and Evolution!

This study was the Ph.D. project of Viet-Dai Dang, at the lab of John Wang. Dai carried out very challenging RNA-seq analyses of the antennae of Solenopsis invicta fire ant workers from different genotype groups of the social chromosome. Amir from our lab contributed to the bioinformatic analysis of these data to identify 81 genes that are differentially expressed between genotype groups. These included 13 genes implicated in chemical metabolism or perception. We were especially interested the differential expression of one odorant receptor (SiOR463) and one odorant binding protein (SiOBP12). We found SiOR463 was deleted in the Sb haplotype of the social chromosome, while SiOBP12 was duplicated in Sb.