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RESEARCH POSTER PRESENTATION DESIGN © 2015 www.PosterPresentations.com Eusociality, the highest level of social organization, has evolved few times. The groups of animals which evolved eusociality include humans and mole rats, along with insects such as ants, termites, and some species of bees and wasps. Since the evolution of eusociality isn't common, the dynamics of how it works are of great interest to sociobioligists. The social structure of ants typically has a queen (or queens), soldiers, workers, drones, and other specialized castes. Traditionally, it was believed that environmental cues lead to the division of labor. This project will look at three recent developments that suggest there is a genetic component to ant social polymorphism. ABSTRACT OBJECTIVE 2014 study conducted by B. Feldmeyer, D. Elsner and S. Foitzik CASE STUDY #1: Temnothorax longispinosus CASE STUDY #2: Vollenhovia emeryi CASE STUDY #3: Pogonomyrmex rugosus 2002 study conducted by G. Julian, J. Fewell, J. Gadau, R. Johnson, D. Larrabee REFERENCES [1] Hasere Ilaclama Antalya. Ants. http://www.hasereilaclamaantalya.net/ wp-content/uploads/2015/05/images-11.jpg, 2015. [Online; accessed 05-December- 2015]. [2] Antwiki. Pogonomyrmex barbatus. http://www.antwiki.org/wiki/Pogonomyrmex_ barbatus, 2015. [Online; accessed 05- December-2015]. [3] Antwiki. Pogonomyrmex rugosus. http://www.antwiki.org/wiki/Pogonomyrmex_ rugosus, 2015. [Online; accessed 05- December-2015]. [4] Antwiki. Temnothorax longispinosus. http://www.antwiki.org/wiki/Temnothorax_ longispinosus, 2015. [Online; accessed 05-December-2015]. [5] Antwiki. Vollenhovia emeryi. http://www.antwiki.org/wiki/Vollenhovia_emeryi, 2015. [Online; accessed 05-December- 2015]. [6] B. Feldmeyer, D. Elsner, and S. Foitzik. Gene expression patterns associated with caste and reproductive status in ants; worker-specific genes are more derived than queenspecific ones. Molecular Biology, 23:151–161, 2014. [7] Glennis E. Julian, Jennifer H. Fewell, Jurgen Gadau, Robert A. Johnson, and Debbie Larrabee. Genetic determination of the queen caste in an ant hybrid zone. Proceedings of the National Academy of Sciences, 99(12):8157–8160, 2002. [8] Michael Lynch and Bruce Walsh. Genetics and Analysis of Quantitative Traits. SinauerAssociates, 1998. 17 [9] Kyohsuke Ohkawara, Megumi Nakayama, Atsumi Satoh, Andreas Trindl, and Jurgen Heinze. Clonal reproduction and genetic caste differences in a queen-polymorphic ant, vollenhovia emeryi. Biology Letters, 2:359–363, 2006. [10] Daniel Stram. Design, Analysis, and Interpretation of Genome-Wide Association Scans (Statistics for Biology and Health). Springer, 2014. [11] Wikipedia. Haplodiploidy. https://en.wikipedia.org/wiki/Haplodiploidy, 2015. [Online; accessed 05-December-2015]. [12] Edward O. Wilson. Sociobiology: The New Synthesis. Belknap Press, 2000. [13] Edward O. Wilson and Bert Hlldobler. Journey to the Ants: A Story of Scientific Exploration. Belknap Press, 1994. Conduct a literature review of the use of modern methods in statistical genetics to study the social behavior of ants. University of Colorado Denver Aaron Nielsen A Survey of Recent Genetic Developments in Ant Social Polymorphism ALL ABOUT ANTS Interesting Facts: - 1% of all insects are ants - Approximately 10 16 ants on Earth - 25% of land-based biomass is ants - 22,000 species of ants Ants are eusocial: 1) Cooperative care of the young 2) Overlapping generations in a colony 3) Division of labor Only a few species are eusocial. Ants and termites are eusocial. Some species of bees and wasps are eusocial. Humans and mole rats are eusocial. Caste structure in ants: 1) Queen(s) – typically the only female reproducing in the colony 2) Workers (female) – typically infertile females that tend the young and forage 3) Males –typically aren’t otherwise involved in the colony besides mating What is haplodiploidy? Haplodiploidy is a sex-determination system in which males develop from unfertilized eggs and are haploid (one set of chromosomes), and females develop from fertilized eggs and are diploid (two sets of chromosomes). Ants utilize the haplodiploid sex-determination system. In many animals, including humans, full-brothers and full- sisters share 50% of their DNA in common. In most ant societies, full-sisters share 75% of their DNA in common, a male shares 50% of his DNA with a full- sister, and a female shares 25% of its DNA with a full-brother. Another interesting fact: male ants don’t have a father but do have a grandfather. Data collection: Colonies of Temnothorax longispinosus were collected at the E. N. Huyck Preserve, Rensselaerville, NY in the summer of 2011. Methods: Queens were removed from the rest of the colony to potentially induce production of reproductive capabilities of the female workers. After the castes were determined along with whether or not the ant possessed reproductive capabilities, RNA was extracted from the sampled ants and was compared. Prior to pre-processing, 55,000 - 97,000 contigs (overlapping portions of RNA) were available. After meta-assembly, 44,797 contigs remained. A total of 11,016 statistically significant expression differences were found using a test for difference in proportions after a FDR correction. 5,346 of the these differences were found to correspond to single genes. Analysis and Results: Using nonmetric multidimensional scaling (NMDS) in two dimensions, there appears to be clear evidence of expression differences between queens, fertile workers, and infertile females (infertile workers and foragers). There appeared to be similar expression patterns for infertile workers and foragers. In addition to noting the overall differences in gene expression utilizing NMDS, the number of shared and private differentially expressed genes was analyzed. These differentially expressed genes are shown in a Venn diagram. Conclusions: This analysis allows for the determination of genes that are regulated differentially for a specific caste. Queens were found to have the most caste-specific genes while infertile workers and foragers tended to express a majority of the genes analyzed in a similar manner. Previous studies had not identified many of these caste-specific gene expressions. It is also notable that there were a significant number worker-specific genes. This study suggests that not only have the phenotypes of queens and non- reproducing females diverged over time, but also that caste-specific genes have evolved. 2006 study conducted by K. Ohkawara, , M. Nakayama, A. Satoh, A. Trindl, J. Heinze Data collection: Colonies of Vollenhovia emeryi were collected in a forest near the coast in Kanazawa City, Japan. Methods: Three DNA microsatellite loci (L-5, L-18, and Myrt-3) were amplified for the collected species and these loci were chosen to utilize primers originally developed for Temnothorax nylanderi and Myrmica tahoensis. Microsatellites are tracts of repeated DNA and can be analyzed for a variety of ends. For this particular study, the goal was to study the direction of genetic flow between castes. DNA was extracted from the sampled ant heads and thoraces and the microsatellites at the three loci were amplified using PCR technology. Microsatellite alleles were identified using software and comparisons were made between castes using allele frequencies. Analysis and Results: A variety of statistical methods were used to analyze the data. First, a F-test was used within a hierarchical framework to analyze the molecular variance of the complete sample of genotypes. This was found to have a statistically significant excess of heterozygotes at L-5 for workers in comparison to fertile females and queens (95% CI: (-0.578,-0.192)). Both the long-winged and the short- winged colonies exhibited statistically significant differences in molecular variance using the aforementioned method. In addition, a chi-squared test was calculated to assess if there was a difference in allele frequencies between castes. A statistically significant difference (p-value < 0.0001) was found in the frequency of homozygotes between queens and workers at the L-5 locus. Nonmetric multidimensional scaling (NMDS) plot of differentially expressed genes in Temnothorax longispinosus Venn diagram depicting the patterns of private and shared differentially expressed genes among the female castes Frequency of homozygous and heterozygous queens and workers from Vollenhovia emeryi colonies with long- winged queens (LQ, LQW) and colonies with short- winged queens (SQ, SQW) at the microsatellite loci (a) L-5 (b) L-18 and (c) Myrt-3 Conclusions: These statistical methods, along with some additional results, gave three surprising results. The first result was the long-winged and the short- winged colonies were genetically differentiated. In particular, while the queens and fertile female were primarily homozygous at the three loci, they exhibited different alleles. At L-5, long-winged queens primarily had the genotype aa while the short-winged queens exclusively had the genotypes cc and dd. The second surprising result was that the workers were primarily heterozygous while the queens and fertile females were nearly exclusively homozygous. The final interesting result was that the males (at least in the short-winged colonies) appeared to carry the allele of the queen's mate. This last result is particularly surprising as male ants typically develop from an unfertilized egg. Within this species, it appears that at least a portion of the genetic information that males receive is from the queen's mate. Data collection: Samples of each species were collected during mating season in areas of sympatry and allopatry within the states of Arizona, New Mexico, and Texas. Methods: DNA was extracted from the abdomens of the ants after their caste was determined. Randomly amplified polymorphic DNA (RAPD) genetic markers were used to examine genotypic differences between workers, queens, and males. Previous data has suggested hybridization occurs between the two species in areas of overlap and studies have shown that both species often have mtDNA (mitochondrial DNA) of the other species. A specific primer, C9, was chosen, as it was found to be particularly useful for identifying heterozygotes. Genotypes based on C9 marker with two different alleles, one at 510 bp and one at 550bp Analysis and Results: A chi-squared test was completed and found that there is a significant difference in the proportion of homozygotes between P. rugosus allopatric and sympatric colonies ( " =26.1, p-value < 0.0001). In addition, there was a statistically significant difference in the proportion of homozygotes in P. barbatus allopatric and sympatric colonies ( " = 40.0, p-value < 0.0001). Conclusions: These statistical results give some interesting conclusions. First of all, whether the C9 marker was heterozygous or homozygous is a very good indicator of whether the ant became a queen or a worker. This shouldn't be interpreted to mean that this gene is causal in determining caste, but rather that some structure of interbreeding is occurring. Unlike the previous case study of Vollenhovia emeryi, the males in these colonies appeared to inherit their genes exclusively from the queen mother. The alleles present in the workers that were not present in the males suggest they were inherited from the queen's mate. Crustacean era (~92,000,000 million years old) ants fossilized in amber
