Camponotus mating flight

On the first really hot day of spring Camponotus have their mating flights. Today we collected C. fellah from the population that lives on campus in the Weizmann Institute (because that's where samples for GAGA reference genome sequencing were collected). With the help of Ofer Feinrman and his group we managed to collect very large numbers of males from multiple colonies. We have more than 100 males from a single large colony, which is ideal for our purpose - genomic map construction (as part of our BSF project). The samples will be processed for DNA extraction and RAD-seq library construction by our robot Noah. The sequencing data will be used for genotype calling and linkage map construction. Here are some photos, taken by Pnina obviously:

 

Microbiome workshop

Our workshop on "Omics for environmental and host-associated microbiomes" was a smashing success (see the program). With more than 40 participants we could not find one who was not excited and ecstatic about microbiomes and metagenomes. This was the fifth Haifa winter workshop in bioinformatics and genomics. We're now trying to decide the topic for next year...

Microbiome workshop participants

BSF project kick started

We kick started our joint BSF project on genome evolution in ants. Jessica Purcell and Alan Brelsford visited us in Haifa and we started to outline the four year project in detail. We arranged the collection of samples from ten ant genera by GAGA collaborators and us. We planned our methodologies, including sample processing, genomic sequencing, and construction of genomic maps. We're going to use our robot for all the lab work. For the construction of linkage maps, we met with Abraham Korol, our next door neighbour and a leading expert in this field. We started to use the software package that was developed in his lab - MultiPoint. We also started a preliminary comparative analysis - comparing the chromosomes of Formica and Cataglyphis - which revealed some very interesting stuff... We're going to get some great insights into the evolutionary stories of these genomes from such data. Finally, we did a quick tour of the south of Israel, including the Negev desert and the Dead Sea. It was great having you over Jessica and Alan!

Jessica, Alan and Eyal

Association between aggression and the presence of sexuals

 Shani found an interesting link between the level of aggression between workers from different monogyne Cataglyphis niger colonies and whether or not sexuals (gynes or drones) were present in the nest:

These are results from behavioral assays of dyadic encounters between a pair of workers from different colonies. There was a substantially elevated level of aggression (* indicates statistical significance in Kruskal-Wallis tests) in encounters between workers that came from two nests where we found sexuals (S-S) relative to encounters where one or both workers came from nests where we did not find sexuals (N-S or N-N). Note that all of the ants in this experiment were sampled at the same time during the reproductive season (just before the sexuals leave the nests for their mating flight). Interestingly, Shani also observed that nests that produce gynes are a little more aggressive than nests that produce drones.

Shani also analyzed the cuticular hydrocarbons (CHC) of the same colony samples, which are known to be the chemical cues used by ants to recognize their nestmates. She tested for an association between chemical dissimilarity of different colonies and the aggression in their interactions. Surprisingly, there wasn't much of an association between the two variables, except for a slight positive correlation for the nests that had sexuals (that were more aggressive in general):

One might expect that ants would be more aggressive towards non-nestmates that come from colonies with a more dissimilar colony odor, but this does not appear to have a substantial effect on their aggressiveness.

Shani also confirmed the "nasty neighbor" effect, which was previously reported in Cataglyphis. For more details please check out our paper on bioRxiv (now in review).

 

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