SEX ALLOCATION CONFLICT IN ANTS WHEN THE QUEEN

SEX ALLOCATION CONFLICT IN ANTS: WHEN THE QUEEN RULES Group 5: Dmitrieva Maria Dankbaar Martje Konik Anastasia Ponizovskiy Vladimir Sivova Alexandra Steblovskaya Kseniya

THE SOCIAL STRUCTURE OF ANTS: Do nothing but children. Can choose the Sex of the future insect at the stage of Egg - Male or Female. Help Queen make children Do everything necessary for life, but can’t make children. Can raise a female Egg as Queen or Worker

STAGES OF ADULT ANT DEVELOPING Que en the choos sex e Workers choose Queen or Worker Pupae, whatever ☺

DIFFERENT TYPES OF ANT COLONIES Colonies differs in the quantity of Queens in them: One Single mated Queen One Double mated Queen Many Queens in colonies And colonies specify on the Males production or the Female production

HOW MANY TO PRODUCE MALES AND FEMALES? Males are haploid, females are diploid Workers are more genetically related to sisters than to brothers; Queens are equally related to both sexes Workers want there to be more females than males. Queens want an equal representation

HOW MANY TO PRODUCE MALES AND FEMALES? According to my Genes, for each Female we need on Male 1: 1 According to MINE we need more FEMALES! They are more like me 3: 1

THE CURRENT RESEARCH How many female Egges and Pupas in comparison with male How “caring resources” of Workers distributed among Female and Males Does the difference exist between Genetically assumed relatedness in quantity of Male and Female species and Real relatedness?

“SAMPLE” Formica selysi ants 112 colonies (from 8 to 100 from each colony at nine microsatellite marker*) There are: 57% - Singe mated Queen 6% - Double mated Queen 37% - multiple Queens *the “magic” procedure of defining the genes

EXPERIMENTAL PROCEDURE Revision during 2001 and 2002 Sampled pupae three or four times between mid May and the end by June Pupae were marked and after that returned to the colonies Using microsatellite markers for assessing Genetically assumed relatedness of Female and Male ants

TURN TO THE SPECIFIC TERMS How many Males and Females Sex Allocation Sex allocation according to Genes Relatedness asymmetry (Relatedness of female divided by the relatedness of males) “Concern” of Worker ant for developing adult ant Sex-investment ration ≈ related of female weight to the colonies productivities

RESULT: SEX-INVESTMENT RATIO 2001 2002 Sex-investment ration (expressed the proportion of energy allocated to females ) in colonies headed by one singly mated queen (black bars), one doubly mated queen (grey bars) and multiple queens (whitу bars), respectively A – 2001, B - 2002

RESULTS: THE PROPORTION OF FEMALE EGGS AND PUPAES Relationship between the sex ration of pupae (proportion of queens) and eggs (proportion of diploid eggs). N=31 colonies; note that 13 colonies had only haploid eggs and male pupae, whereas five colonies had only diploid eggs and female pupae

RESULTS: RELATEDNESS ASYMMETRY The population relatedness asymmetry was: 1. 36: 1 (n=49) Theoretical relatedness asymmetry for Queens: 1: 1 The relatedness asymmetry for Workers: 1. 87: 1 (n=26) => Workers have some impact on sex allocation

CONCLUSION Queens limit workers’ influence over sex allocation by producing predominantly one sex Workers still influence sex allocation somewhat by killing male eggs and culling males The resulting overall sex allocation ratio (1. 36: 1) is in between Queen’s preference (1: 1) and worker’s preference (1. 87: 1) Balance of power

GENERAL CONCLUSION Queens can gain control over colony sex allocation by the quantity and quality of Eggs Relatedness-induced Worker control of sexallocation is far from universal Small differences in social structure, ecology, and life history are likely to affect the balance of power between queens and workers

THANK YOU FOR ATTENTION! *AND PATIENCE