Current Status of a Model System: The Gene Gp-9 and Its Association with Social Organization in Fire Ants

The Gp-9 gene in fire ants represents an important model system for studying the evolution of social organization in insects as well as a rich source of information relevant to other major evolutionary topics. An important feature of this system is that polymorphism in social organization is completely associated with allelic variation at Gp-9, such that single-queen colonies (monogyne form) include only inhabitants bearing B-like alleles while multiple-queen colonies (polygyne form) additionally include inhabitants bearing b-like alleles. A recent study of this system by Leal and Ishida (2008) made two major claims, the validity and significance of which we examine here. After reviewing existing literature, analyzing the methods and results of Leal and Ishida (2008), and generating new data from one of their study sites, we conclude that their claim that polygyny can occur in Solenopsis invicta in the U.S.A. in the absence of expression of the b-like allele Gp-9b is unfounded. Moreover, we argue that available information on insect OBPs (the family of proteins to which GP-9 belongs), on the evolutionary/population genetics of Gp-9, and on pheromonal/behavioral control of fire ant colony queen number fails to support their view that GP-9 plays no role in the chemosensory-mediated communication that underpins regulation of social organization. Our analyses lead us to conclude that there are no new reasons to question the existing consensus view of the Gp-9 system outlined in Gotzek and Ross (2007)

Zastosowanie metody Godeta dla analizy tureckiego przemysłu odzieżowego

The value of Turkish textile and apparel trade has shown steady growth since the 1980s, making this one of the indispensable sectors for the Turkish economy. However, especially after 2000, the dramatic effects of globalisation and liberalisation began to be felt in world textile and apparel trade, subsequently changing the dynamics. Companies working in the textile business were compelled to make strategic adjustments in order to determine their future opportunities. Scenario planning enables managers to better analyse the future environment than when using other techniques. In this study, Godet’s scenario planning methodology was applied to the Turkish apparel industry in order to determine future perspectives the industry would face.Obroty tureckiego handlu tekstylno-odzieżowego wykazywały stały wzrost od 1980 roku, co czyni go jednym z niezbędnych sektorów tureckiej gospodarki. Jednak, zwłaszcza po roku 2000, dramatyczne skutki globalizacji i liberalizacji zaczęły być odczuwalne na światowych rynkach branży tekstylno-odzieżowej, zmieniając jej dynamikę. Firmy działające w sektorze tekstylnym zostały zmuszone do podejmowania strategicznych zmian w celu określenia ich przyszłych możliwości. Planowanie scenariuszowe umożliwia menedżerom lepiej przeanalizować przyszłe środowiska, niż przy użyciu innych technik. W tym badaniu metoda scenariuszowa Godeta została zastosowana dla tureckiego przemysłu odzieżowego w celu określenia jego przyszłych perspektyw

Opracowanie strategii rozwoju i oceny tureckiego przemysłu odzieżowego poprzez sporządzenie odpowiednich scenariuszy

The Turkish textile and apparel industry is losing ground as a global player. This forces it to make a careful future analysis to determine the road map ahead and to develop appropriate strategies. Since long term success heavily depends on the development and implementation of strategies that best respond to future requirements for achieving objectives, this study aims to develop strategies for the Turkish apparel industry and determine key strategies among them with a procedure that enables users to make a strategy assessment. For this aim, an approach involving scenario development and strategy appraisal is proposed and applied to the Turkish apparel industry. After describing the general framework of the application, main issues and findings are summarised for the industry and companies acting in the field.Turecki przemysł tekstylny i odzieżowy traci swoją wiodącą pozycję. Wymusza to staranną analizę przyszłych działań dla określenia kierunku rozwoju i opracowania odpowiednich strategii. Ponieważ długotrwający sukces silnie zależy od rozwoju i wprowadzenia strategii, które najlepiej odpowiadałyby przyszłym wymaganiom dla uzyskania sukcesu w artykule opracowano scenariusze dla przemysłu i dla firm działających w tym przemyśle

Fire ants self-assemble into waterproof rafts to survive floods

Why does a single fire ant Solenopsis invicta struggle in water, whereas a group can float effortlessly for days? We use time-lapse photography to investigate how fire ants S. invicta link their bodies together to build waterproof rafts. Although water repellency in nature has been previously viewed as a static material property of plant leaves and insect cuticles, we here demonstrate a self-assembled hydrophobic surface. We find that ants can considerably enhance their water repellency by linking their bodies together, a process analogous to the weaving of a waterproof fabric. We present a model for the rate of raft construction based on observations of ant trajectories atop the raft. Central to the construction process is the trapping of ants at the raft edge by their neighbors, suggesting that some “cooperative” behaviors may rely upon coercion

Effects of the social environment on the survival and fungal resistance of ant brood

The phenotype of social animals can be influenced by genetic, maternal and environmental effects, which include social interactions during development. In social insects, the social environment and genetic origin of brood can each influence a whole suite of traits, from individual size to caste differentiation. Here, we investigate to which degree the social environment during development affects the survival and fungal resistance of ant brood of known maternal origin. We manipulated one component of the social environment, the worker/brood ratio, of brood originating from single queens of Formica selysi. We monitored the survival of brood and measured the head size and ability to resist the entomopathogenic fungus Beauveria bassiana of the resulting callow workers. The worker/brood ratio and origin of eggs affected the survival and maturation time of the brood and the size of the resulting callow workers. The survival of the callow workers varied greatly according to their origin, both in controls and when challenged with B. bassiana. However, there was no interaction between the fungal challenge and either the worker/brood ratio or origin of eggs, suggesting that these factors did not affect parasite resistance in the conditions tested. Overall, the social conditions during brood rearing and the origin of eggs had a strong impact on brood traits that are important for fitness. We detected a surprisingly large amount of variation among queens in the survival of their brood reared in standard queenless conditions, which calls for further studies on genetic, maternal and social effects influencing brood development in the social insects