scholarly journals Does Communal Breeding Promote an Increase in Social Immunity in Burying Beetles? A Test Case with Nicrophorus Defodiens

2021 ◽  
Author(s):  
Megha R Suswaram ◽  
Mark Belk ◽  
Curtis Creighton

Communal breeding is a reproductive system in which more than a single pair of individuals share parental care duties. Burying beetles (genus Nicrophorus) breed on small vertebrate carcasses, which is used as a food source for their young. On larger carcasses, burying beetles will breed communally, forming multiple male-female associations. A significant and costly component of parental investment by burying beetles is the preservation of the carcass with secretions containing immune molecules. Because this immune investment is for the benefit of the offspring, the behavior is a form of social immunity. We test the hypothesis that communal breeding in burying beetles evolved as a mechanism to increase the social immune investment on larger carcasses, which are more difficult to preserve. We used N. defodiens, a communal breeding burying beetle species to test the hypothesis. There were two experimental treatments wherein, the females either bred communally or non-communally. Our results show that the combined immune activity in the secretions were higher in communally breeding pairs than in the immune contribution of single male-female pairs. However, subordinate females were rarely observed on the carcass, and the level of social immune activity of dominant females was lower than females breeding singly. These data suggest that communal breeding in N. defodiens decreases the level of investment in social immunity. Our results demonstrate that the presence of multiple females, which is common under natural conditions, can greatly complicate patterns of social immunity investment in burying beetles.

2015 ◽  
Author(s):  
William JP Palmer ◽  
Ana Duarte ◽  
Matthew Schrader ◽  
Jonathan P Day ◽  
Rebecca Kilner ◽  
...  

Some group-living species exhibit social immunity, where the immune system of one individual can protect others in the group from infection. In burying beetles this is part of parental care. Larvae feed on vertebrate carcasses which their parents smear with exudates that inhibit microbial growth. We have sequenced the transcriptome of the burying beetle Nicrophorus vespilloides and identified six genes that encode lysozymes – a type of antimicrobial enzyme that has previously been implicated in social immunity in burying beetles. When females start breeding and producing antimicrobial anal exudates, we found that the expression of one of these genes was increased by ~1000 times to become one of the most abundant transcripts in the transcriptome. We conclude that we have likely identified a gene for social immunity, and that it was recruited during evolution from a previous function in personal immunity.


2019 ◽  
Author(s):  
Syuan-Jyun Sun ◽  
Rebecca M. Kilner

AbstractSymbiotic organisms adapt to one another but the extent of co-adaptation commonly varies among pairs of the same symbiotic species drawn from different populations. Here we identify some ecological causes of such differences between populations. We analysed the extent of local co-adaptation between burying beetles Nicrophorus vespilloides and their phoretic mites Poecilochirus carabi in Gamlingay and Waresley Woods, in Cambridgeshire, UK. Burying beetles transport mites to small vertebrate carrion upon which they both reproduce. We conducted reciprocal transplant experiments to test for evidence of local co-adaptation during reproduction. We found variation in the extent of local co-adaptation that was explained by cryptic host specialisation within P. carabi mites. P. carabi is a species complex, within which races of mites are specialised to associate with different species of burying beetle. We found that N. vespilloides from Gamlingay Wood carries a mixture of mite races, from each of the four Nicrophorus species that inhabits this wood. This mixture of races makes P.carabi harmful to Gamlingay N. vespilloides: together, they reduce beetle reproductive success. Experimentally purifying mites, so that Gamlingay N. vespilloides is associated only with the vespilloides mite race, improves beetle reproductive success. Waresley N. vespilloides, by contrast, carry a near pure race of vespilloides mites, which cause negligible damage to Waresley N. vespilloides reproductive success. This is probably because Waresley Wood harbours only two burying beetle species, which differ markedly in their reproductive biology. Cryptic host specialisation with P. carabi mites, combined with differences in the Nicrophorus guild between Gamlingay and Waresley Woods, therefore explain population differences in the extent of local adaptation between N. vespilloides and P. carabi.


2016 ◽  
Vol 283 (1823) ◽  
pp. 20152733 ◽  
Author(s):  
William J. Palmer ◽  
Ana Duarte ◽  
Matthew Schrader ◽  
Jonathan P. Day ◽  
Rebecca Kilner ◽  
...  

Some group-living species exhibit social immunity, where the immune response of one individual can protect others in the group from infection. In burying beetles, this is part of parental care. Larvae feed on vertebrate carcasses which their parents smear with exudates that inhibit microbial growth. We have sequenced the transcriptome of the burying beetle Nicrophorus vespilloides and identified six genes that encode lysozymes—a type of antimicrobial enzyme that has previously been implicated in social immunity in burying beetles. When females start breeding and producing antimicrobial anal exudates, we found that the expression of one of these genes was increased by approximately 1000 times to become one of the most abundant transcripts in the transcriptome. Females varied considerably in the antimicrobial properties of their anal exudates, and this was strongly correlated with the expression of this lysozyme. We conclude that we have likely identified a gene encoding a key effector molecule in social immunity and that it was recruited during evolution from a function in personal immunity.


2021 ◽  
Vol 118 (48) ◽  
pp. e2102450118
Author(s):  
Ana Duarte ◽  
Darren Rebar ◽  
Allysa C. Hallett ◽  
Benjamin J. M. Jarrett ◽  
Rebecca M. Kilner

Parental care can be partitioned into traits that involve direct engagement with offspring and traits that are expressed as an extended phenotype and influence the developmental environment, such as constructing a nursery. Here, we use experimental evolution to test whether parents can evolve modifications in nursery construction when they are experimentally prevented from supplying care directly to offspring. We exposed replicate experimental populations of burying beetles (Nicrophorus vespilloides) to different regimes of posthatching care by allowing larvae to develop in the presence (Full Care) or absence of parents (No Care). After only 13 generations of experimental evolution, we found an adaptive evolutionary increase in the pace at which parents in the No Care populations converted a dead body into a carrion nest for larvae. Cross-fostering experiments further revealed that No Care larvae performed better on a carrion nest prepared by No Care parents than did Full Care larvae. We conclude that parents construct the nursery environment in relation to their effectiveness at supplying care directly, after offspring are born. When direct care is prevented entirely, they evolve to make compensatory adjustments to the nursery in which their young will develop. The rapid evolutionary change observed in our experiments suggests there is considerable standing genetic variation for parental care traits in natural burying beetle populations—for reasons that remain unclear.


2018 ◽  
Vol 285 (1885) ◽  
pp. 20181452 ◽  
Author(s):  
Benjamin J. M. Jarrett ◽  
Darren Rebar ◽  
Hannah B. Haynes ◽  
Miranda R. Leaf ◽  
Chay Halliwell ◽  
...  

Interactions among siblings are finely balanced between rivalry and cooperation, but the factors that tip the balance towards cooperation are incompletely understood. Previous observations of insect species suggest that (i) sibling cooperation is more likely when siblings hatch at the same time, and (ii) this is more common when parents provide little to no care. In this paper, we tested these ideas experimentally with the burying beetle, Nicrophorus vespilloides . Burying beetles convert the body of a small dead vertebrate into an edible nest for their larvae, and provision and guard their young after hatching. In our first experiment, we simulated synchronous or asynchronous hatching by adding larvae at different intervals to the carrion-breeding resource. We found that ‘synchronously’ hatched broods survived better than ‘asynchronously’ hatched broods, probably because ‘synchronous hatching’ generated larger teams of larvae, that together worked more effectively to penetrate the carrion nest and feed upon it. In our second experiment, we measured the synchronicity of hatching in experimental populations that had evolved for 22 generations without any post-hatching care, and control populations that had evolved in parallel with post-hatching care. We found that larvae were more likely to hatch earlier, and at the same time as their broodmates, in the experimental populations that evolved without post-hatching care. We suggest that synchronous hatching enables offspring to help each other when parents are not present to provide care. However, we also suggest that greater levels of cooperation among siblings cannot compensate fully for the loss of parental care.


2016 ◽  
Author(s):  
Ana Duarte ◽  
Martin Welch ◽  
Josef Wagner ◽  
Rebecca M. Kilner

AbstractIt is still poorly understood how animal behaviour shapes bacterial communities and their evolution. We use burying beetles,Nicrophorus vespilloides, to investigate how animal behaviour impacts the assembly of bacterial communities. Burying beetles use small vertebrate carcasses as breeding resources, which they roll into a ball, smear with antimicrobial exudates and bury. Using high-throughput sequencing we characterize bacterial communities on fresh mouse carcasses, aged carcasses prepared by beetles, and aged carcasses that were manually buried. The long-standing hypothesis that burying beetles ‘clean’ the carcass from bacteria is refuted, as we found higher loads of bacterial DNA in beetle-prepared carcasses. Beetle-prepared carcasses were similar to fresh carcasses in terms of species richness and diversity. Beetle-prepared carcasses distinguish themselves from manually buried carcasses by the reduction of groups such as Proteobacteria and increase of groups such as Flavobacteriales and Clostridiales. Network analysis suggests that, despite differences in membership, network topology is similar between fresh and beetle-prepared carcasses. We then examined the bacterial communities in guts and exudates of breeding and non-breeding beetles. Breeding was associated with higher diversity and species richness. Breeding beetles exhibited several bacterial groups in common with their breeding resource, but that association is likely to disappear after breeding.


PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0255660
Author(s):  
Christian O. Ayala-Ortiz ◽  
Jacob W. Farriester ◽  
Carrie J. Pratt ◽  
Anna K. Goldkamp ◽  
Jessica Matts ◽  
...  

Nicrophorus is a genus of beetles that bury and transform small vertebrate carcasses into a brood ball coated with their oral and anal secretions to prevent decay and that will serve as a food source for their young. Nicrophorus pustulatus is an unusual species with the ability to overtake brood of other burying beetles and whose secretions, unlike other Nicrophorus species, has been reported not to exhibit antimicrobial properties. This work aims to better understand how the presence or absence of a food source influences the expression of genes involved in the feeding process of N. pustulatus. To achieve that, total RNA was extracted from pooled samples of salivary gland tissue from N. pustulatus and sequenced using an Illumina platform. The resulting reads were used to assemble a de novo transcriptome using Trinity. Duplicates with more than 95% similarity were removed to obtain a “unigene” set. Annotation of the unigene set was done using the Trinotate pipeline. Transcript abundance was determined using Kallisto and differential gene expression analysis was performed using edgeR. A total of 651 genes were found to be differentially expressed, including 390 upregulated and 261 downregulated genes in fed insects compared to starved. Several genes upregulated in fed beetles are associated with the insect immune response and detoxification processes with only one transcript encoding for the antimicrobial peptide (AMP) defensin. These results confirm that N. pustulatus does not upregulate the production of genes encoding AMPs during feeding. This study provides a snapshot of the changes in gene expression in the salivary glands of N. pustulatus following feeding while providing a well described transcriptome for the further analysis of this unique burying beetle.


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