Limits...
Gene expression and the evolution of phenotypic diversity in social wasps.

Hoffman EA, Goodisman MA - BMC Biol. (2007)

Bottom Line: Furthermore, we compared the patterns found in this species to those found in other taxa in order to investigate how variation in gene expression leads to phenotypic evolution.In this study, we found that comparisons of patterns of gene expression with model systems highlighted areas of conserved and convergent developmental evolution across diverse taxa.Finally, overall differences between social insect taxa suggest that the independent evolution of caste arose via distinct developmental trajectories.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biology, University of Central Florida, Orlando, FL 32816, USA. eahoffma@mail.ucf.edu

ABSTRACT

Background: Organisms are capable of developing different phenotypes by altering the genes they express. This phenotypic plasticity provides a means for species to respond effectively to environmental conditions. One of the most dramatic examples of phenotypic plasticity occurs in the highly social hymenopteran insects (ants, social bees, and social wasps), where distinct castes and sexes all arise from the same genes. To elucidate how variation in patterns of gene expression affects phenotypic variation, we conducted a study to simultaneously address the influence of developmental stage, sex, and caste on patterns of gene expression in Vespula wasps. Furthermore, we compared the patterns found in this species to those found in other taxa in order to investigate how variation in gene expression leads to phenotypic evolution.

Results: We constructed 11 different cDNA libraries derived from various developmental stages and castes of Vespula squamosa. Comparisons of overall expression patterns indicated that gene-expression differences distinguishing developmental stages were greater than expression differences differentiating sex or caste. Furthermore, we determined that certain sets of genes showed similar patterns of expression in the same phenotypic forms of different species. Specifically, larvae upregulated genes related to metabolism and genes possessing structural activity. Surprisingly, our data indicated that at least a few specific gene functions and at least one specific gene family are important components of caste differentiation across social insect taxa.

Conclusion: Despite research on various aspects of development originating from model systems, growth in understanding how development is related to phenotypic diversity relies on a growing literature of contrasting studies in non-model systems. In this study, we found that comparisons of patterns of gene expression with model systems highlighted areas of conserved and convergent developmental evolution across diverse taxa. Indeed, conserved biological functions across species implicated key functions related to how phenotypes are built. Finally, overall differences between social insect taxa suggest that the independent evolution of caste arose via distinct developmental trajectories.

Show MeSH

Related in: MedlinePlus

Relationships among V. squamosa life stages based upon EST frequencies. Colored dots indicate where libraries derived from developmentally similar stages cluster. Q, queen; W, worker; M, male; E, egg; LE, early larval instars; LL, late larval instars; P, pupa; A, adult.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC1884141&req=5

Figure 2: Relationships among V. squamosa life stages based upon EST frequencies. Colored dots indicate where libraries derived from developmentally similar stages cluster. Q, queen; W, worker; M, male; E, egg; LE, early larval instars; LL, late larval instars; P, pupa; A, adult.

Mentions: The most striking result from our data is that developmental stage (i.e., larva, pupa, and adult) plays a much larger role in establishing patterns of gene expression than either caste or sex (Figure 2). In fact, developmental time is the critical factor in grouping the libraries by overall expression pattern. Thus, individuals of the same developmental age express many genes in common regardless of their caste or sex.


Gene expression and the evolution of phenotypic diversity in social wasps.

Hoffman EA, Goodisman MA - BMC Biol. (2007)

Relationships among V. squamosa life stages based upon EST frequencies. Colored dots indicate where libraries derived from developmentally similar stages cluster. Q, queen; W, worker; M, male; E, egg; LE, early larval instars; LL, late larval instars; P, pupa; A, adult.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC1884141&req=5

Figure 2: Relationships among V. squamosa life stages based upon EST frequencies. Colored dots indicate where libraries derived from developmentally similar stages cluster. Q, queen; W, worker; M, male; E, egg; LE, early larval instars; LL, late larval instars; P, pupa; A, adult.
Mentions: The most striking result from our data is that developmental stage (i.e., larva, pupa, and adult) plays a much larger role in establishing patterns of gene expression than either caste or sex (Figure 2). In fact, developmental time is the critical factor in grouping the libraries by overall expression pattern. Thus, individuals of the same developmental age express many genes in common regardless of their caste or sex.

Bottom Line: Furthermore, we compared the patterns found in this species to those found in other taxa in order to investigate how variation in gene expression leads to phenotypic evolution.In this study, we found that comparisons of patterns of gene expression with model systems highlighted areas of conserved and convergent developmental evolution across diverse taxa.Finally, overall differences between social insect taxa suggest that the independent evolution of caste arose via distinct developmental trajectories.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biology, University of Central Florida, Orlando, FL 32816, USA. eahoffma@mail.ucf.edu

ABSTRACT

Background: Organisms are capable of developing different phenotypes by altering the genes they express. This phenotypic plasticity provides a means for species to respond effectively to environmental conditions. One of the most dramatic examples of phenotypic plasticity occurs in the highly social hymenopteran insects (ants, social bees, and social wasps), where distinct castes and sexes all arise from the same genes. To elucidate how variation in patterns of gene expression affects phenotypic variation, we conducted a study to simultaneously address the influence of developmental stage, sex, and caste on patterns of gene expression in Vespula wasps. Furthermore, we compared the patterns found in this species to those found in other taxa in order to investigate how variation in gene expression leads to phenotypic evolution.

Results: We constructed 11 different cDNA libraries derived from various developmental stages and castes of Vespula squamosa. Comparisons of overall expression patterns indicated that gene-expression differences distinguishing developmental stages were greater than expression differences differentiating sex or caste. Furthermore, we determined that certain sets of genes showed similar patterns of expression in the same phenotypic forms of different species. Specifically, larvae upregulated genes related to metabolism and genes possessing structural activity. Surprisingly, our data indicated that at least a few specific gene functions and at least one specific gene family are important components of caste differentiation across social insect taxa.

Conclusion: Despite research on various aspects of development originating from model systems, growth in understanding how development is related to phenotypic diversity relies on a growing literature of contrasting studies in non-model systems. In this study, we found that comparisons of patterns of gene expression with model systems highlighted areas of conserved and convergent developmental evolution across diverse taxa. Indeed, conserved biological functions across species implicated key functions related to how phenotypes are built. Finally, overall differences between social insect taxa suggest that the independent evolution of caste arose via distinct developmental trajectories.

Show MeSH
Related in: MedlinePlus