0000000001308965
AUTHOR
Philip Kohlmeier
When earwig mothers do not care to share: Parent–offspring competition and the evolution of family life
Kin competition often reduces – and sometimes entirely negates – the benefits of cooperation among family members. Surprisingly, the impact of kin competition on the fitness effects of family life only received close scrutiny in studies on sibling rivalry, whereas the possibility of parent–offspring competition has attracted much less attention. As a consequence, it remains unclear whether and how parent–offspring competition could have affected the early evolution of parental care and family life. Here, we examined the occurrence and consequences of parent–offspring competition over food access in the European earwig Forficula auricularia, an insect with facultative family life reminiscent…
Gene expression is more strongly associated with behavioural specialization than with age or fertility in ant workers.
The ecological success of social insects is based on division of labour, not only between queens and workers, but also among workers. Whether a worker tends the brood or forages is influenced by age, fertility and nutritional status, with brood carers being younger, more fecund and more corpulent. Here, we experimentally disentangle behavioural specialization from age and fertility in Temnothorax longispinosus ant workers and analyse how these parameters are linked to whole-body gene expression. A total of 3,644 genes were associated with behavioural specialization which is ten times more than associated with age and 50 times more than associated with fertility. Brood carers were characteri…
Gene expression is stronger associated with behaviour than with age and fertility in ant workers
AbstractThe ecological success of social insects is based on division of labour, not only between queens and workers, but also among workers. Whether a worker tends the brood or forages is strongly influenced by age, fertility and nutritional status, with brood carers being younger, more fecund and corpulent. Here, we experimentally disentangle behaviour from age and fertility inTemnothorax longispinosusant workers and analyse how these parameters are linked to whole-body gene expression. Our transcriptome analysis reveals four times more genes associated with behaviour than with age and only few fertility-associated genes. Brood carers exhibited an upregulation of genes involved in lipid b…
Survival after pathogen exposure in group-living insects: don't forget the stress of social isolation!
A major cost of group-living is its inherent risk of pathogen infection. To limit this risk, many group-living animals have developed the capability to prophylactically boost their immune system in the presence of group members and/or to mount collective defences against pathogens. These two phenomena, called density-dependent prophylaxis and social immunity, respectively, are often used to explain why, in group-living species, individuals survive better in groups than in isolation. However, this survival difference may also reflect an alternative and often overlooked process: a cost of social isolation on individuals' capability to fight against infections. Here, we disentangled the effect…
Vitellogenin-like A–associated shifts in social cue responsiveness regulate behavioral task specialization in an ant
Division of labor and task specialization explain the success of human and insect societies. Social insect colonies are characterized by division of labor, with workers specializing in brood care early and foraging later in life. Theory posits that this task switching requires shifts in responsiveness to task-related cues, yet experimental evidence is weak. Here, we show that a Vitellogenin (Vg) ortholog identified in an RNAseq study on the ant T. longispinosus is involved in this process: using phylogenetic analyses of Vg and Vg-like genes, we firstly show that this candidate gene does not cluster with the intensively studied honey bee Vg but falls into a separate Vg-like A cluster. Second…
PO-CALC: A novel tool to correct common inconsistencies in the measurement of phenoloxidase activity
Abstract A broad range of physiological and evolutionarily studies requires standard and robust methods to assess the strength and activity of an individual’s immune defense. In insects, this goal is generally reached by spectrophotometrically measuring (pro-) phenoloxidase activity, an enzymatic and non-specific process activated after wounding and parasite infections. However, the literature surprisingly lacks a standard method to calculate these values from spectrophotometer data and thus to be able to compare results across studies. In this study, we demonstrated that nine methods commonly used to extract phenoloxidase activities (1) provide inconsistent results when tested on the same …
Data from: Gene expression is more strongly associated with behavioural specialisation than with age or fertility in ant workers
The ecological success of social insects is based on division of labour, not only between queens and workers, but also among workers. Whether a worker tends the brood or forages is influenced by age, fertility and nutritional status, with brood carers being younger, more fecund and more corpulent. Here, we experimentally disentangle behavioural specialisation from age and fertility in Temnothorax longispinosus ant workers and analyse how these parameters are linked to whole-body gene expression. A total of 3644 genes were associated with behavioural specialisation which is ten times more than associated with age and 50 times more than associated with fertility. Brood carers were characteriz…
Data from: When earwig mothers do not care to share: parent-offspring competition and the evolution of family life
1. Kin competition often reduces – and sometimes entirely negates – the benefits of cooperation among relatives, and hence is often regarded as central process in social evolution. Surprisingly, however, our understanding of the role of kin competition in the evolution of family life remains fragmentary, despite the close scrutiny it received in studies on sibling rivarly. This is because much less attention has been given to local competition between parents and their offspring, and its potential impact on the early evolution of parental care and family life. 2. Here, we examined mother-offspring competition over food access in the European earwig Forficula auricularia, an insect with facu…
Data from: Survival after pathogen exposure in group-living insects: don’t forget the stress of social isolation!
A major cost of group-living is its inherent risk of pathogen infection. To limit this risk, many group-living animals have developed the capability to prophylactically boost their immune system in the presence of group members and/or to mount collective defenses against pathogens. These two phenomena, called density dependent prophylaxis and social immunity, respectively, are often used to explain why, in group-living species, individuals survive better in groups than in isolation. However, this survival difference may also reflect an alternative and often overlooked process: a cost of social isolation on individuals’ capability to fight against infections. Here, we disentangled the effect…
Data from: Vitellogenin-like A–associated shifts in social cue responsiveness regulate behavioral task specialization in an ant
Division of labor and task specialization explain the success of human and insect societies. Social insect colonies are characterized by division of labor with workers specializing on brood care early and foraging later in life. Theory posits that this task switching requires shifts in responsiveness to task-related cues, yet experimental evidence is weak. Here we show that a Vitellogenin (Vg) ortholog identified in a RNAseq study on the ant Temnothorax longispinosus is involved in this process: Using phylogenetic analyses of Vg and Vg-like genes, we firstly show that this candidate gene does not cluster with the intensively studied honey bee Vg, but falls into a separate Vg-like A cluster.…