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4. Host-parasite dynamics lead to mixed cooperative games

Creator:
Stopka, Pavel and Johnson, D. P.
Type:
article, model:article, and TEXT
Subject:
Prisoner’s dilemma, Mutualism, Cruel Bind, ectoparasites, fleas, and cooperation
Language:
English
Description:
Although the Prisoner’s dilemma is a leading metaphor for the evolution of sociality, only a few studies demonstrate that this game indeed operates in nature. We offer an alternative perspective, in which parasites and their hosts are used as a model system, suggesting that Prisoner’s dilemma may be rare due to different individuals experiencing variation in the payoffs they receive from alternative strategies. Ectoparasites (such as fleas) move stochastically between hosts, causing differential parasite burdens. The resulting variance in the need for cooperation – in this case cooperative allogrooming – means that payoffs for different strategies (e.g. cooperate and defect) are not fixed. Our simulations revealed that due to parasite dynamics, cooperation among hosts conforms to a mixture of two games: Mutualism and Cruel Bind, both of which are more likely to coerce individuals into mutual cooperation than Prisoner’s dilemma. Though interesting, Prisoner’s dilemma is in fact the least likely scenario. If payoff variation is common, the dominance of the Prisoner’s dilemma paradigm may have made us unnecessarily puzzled by cooperation in nature.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

5. Inbreeding does not reduce aggressiveness in wild male mice, Mus musculus

Creator:
Thob, Michaela, Ilmonen, Petteri, Penn, Dustin J., Stopka, Pavel, and Dvořáková-Hortová, Kateřina
Type:
article and TEXT
Subject:
aggression, Salmonella, and wild house mouse
Language:
English
Description:
Inbreeding reduces quality and survival of offspring due to increased homozygosity and the expression of recessive deleterious mutations. However, there are only few studies examining how inbreeding affects behavior in adults. We aimed to replicate an earlier study in wild house mice by inducing a stress factor - infection with Salmonella. To examine whether less inbred males are more aggressive and have a higher probability to win brief encounters, we confronted full-sib inbred and outbred males in a neutral arena and recorded aggressive as well as defensive behaviors. Contrary to our expectations, any effects of inbreeding on aggressive and defensive behaviors were not dependent on infection status. Furthermore neither infection treatment nor inbreeding affected the amount of aggressive and defensive behaviors displayed by males. Short-term aggression assays may be a useful tool for investigating certain aspects of aggressive behavior; however, long-term aggression assays might be more suitable to monitor all aspects of competitive ability and antagonistic interactions as well as effects of certain treatments on competitive ability and aggressiveness. These results may have important implications for opposed selection pressures arising from female choice and male-male competition.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/

6. influence of olfactory stimulus and sexual activity on gonadal steroids in eusocial mole-rats

Creator:
Hagemeyer, Petra, Lange, Simone, Broecker-Preuss, Martina, Burda, Hynek, Stopka, Pavel, and Dvořáková-Hortová, Kateřina
Type:
article and TEXT
Subject:
estrus, colpocytology, and Fukomys
Language:
English
Description:
The two studied sibling species of African mole-rats, Fukomys anselli and F. kafuensis, are blind, subterranean rodents that live in an eusocial families with only a single pair breeding whilst its offspring exhibit prolonged philopatry and do not breed. The reproductive skew is caused by incest avoidance through individual recognition of family members. The aim of the study is to contribute to basic understanding of priming capacities of olfactory stimuli and reproductive activity on biological state of a female. We compared hormonal profiles (normalized urinary estradiol- and progesterone concentration (mg/crea) and their temporal changes in females throughout three different test phases: I. Five week phase without manipulation; II. Five day phase with olfactory stimulation with odours of potential repreductive partners; III. Five day phase wih reproductive stimulation with respective partners. Colpocytology was performed to correlate spontaneous or induced estrus with vaginal cytological findings. There was a strong correlation between sexual activity of females (queens) on one side and high mean estradiol and progesterone levels on the other side as well as estradiol increase triggered by mating. No correlation was found between estrus phase and typical estrus like cells in colpocytological examinations.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/

8. Mechanisms of chemical communication: the role of Major Urinary Proteins

Creator:
Janotová, Kateřina, Stopka, Pavel, and Dvořáková-Hortová, Kateřina
Type:
article and TEXT
Subject:
lipocalins, MUP, Mus, mouse, and social modulation
Language:
English
Description:
Social communication in the house mouse relies heavily on pheromone-carrying major urinary proteins (MUPs), which delay release of pheromones thus extending longevity of the scent signal. Moreover, MUPs appear to play an important role in individual recognition. In the last few years, new research has led to some important advances. It has been shown that MUPs without their volatile ligands are able to activate neurons in vomeronasal organ and elicit behavioural and physiological responses in the signal receiver. Furthermore, increasing evidence has been found showing that, contrary to the traditional view, MUP expression is condition and state dependent, and that this variation may provide additional information about an individual. Progress has also been made in the description of MUP-like proteins in other rodents; as yet, however, the protein variability typical of the house mouse has not been observed in any other species. Despite these new results, the concept of MUPs has remained more or less unchanged from the date they were first recognized as an identity signal. The aim of this review is to summarise recent knowledge about MUPs and to discuss previous findings in the light of novel facts. Special attention is paid to the consequences the new results may have on our understanding of the individual recognition role of MUPs.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/

9. Monitoring and prevalence of influenza A virus in the population of mallard duck in the Czech Republic between 2008-2010

Creator:
Ryba, Štěpán and Stopka, Pavel
Type:
article, model:article, and TEXT
Subject:
PCR and detection
Language:
English
Description:
In the current study 744 cloacal samples were collected from mallards (Anas platyrhynchos) in the Czech Republic and tested for the presence of influenza virus between 2008 and 2010. Of the total number of 744 mallards tested nine were positive (prevalence 1.2 %) for influenza virus. All the mallards were up to 1.5 years old and the majority (89 %) were killed by hunters.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

10. Multiple roles of secretory lipocalins (Mup, Obp) in mice

Creator:
Stopková, Romana, Hladovcová, Denisa, Kokavec, Juraj, Vyoral, Daniel, Stopka, Pavel, and Dvořáková-Hortová, Kateřina
Type:
article and TEXT
Subject:
urinary proteins and chemical communication
Language:
English
Description:
Many biological processes involve globular transport proteins belonging to a family called lipocalins. The prominent feature in lipocalin structure is their specific tertiary conformation forming eight-stranded beta barrel with capacity to bind various ligands inside. The importance of lipocalins is evident from the list of vital substances (Hydrophobic ligands including vitamin A, steroids, bilins, lipids, pheromones etc.) that these proteins transport and from their high expression levels in various tissues. Among wide spectrum of lipocalins, Major Urinary Proteins (Mup) and Odorant Binding Proteins (Obp) are well known for their capacity to bind and carry odorants / pheromones and have been studied to detail in various mammalian models including mice, rats, and hamsters. However, many lipocalins (also including Mups) have previously been described with respect to their protective function in mammalian organism where they transport potentially harmful molecules to a degradation site (e. g. lysozomes) or straight out of the body. As most of lipocalins share similar tertiary structure, their potential role in both transport and excretion processes may be additive or complementary. In addition to a role of lipocalins in chemical communication this review presents lipocalins from the point of view of the "toxic waste hypothesis". This hypothesis assumes that members of lipocalins that are linked to a metabolic degradation of their ligands were an ideal source for natural selection during evolution due to an ability of potential receivers to detect lipocalin ligands levels as a signal by other individuals.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/