1
|
Nicholson RM, Levis NA, Ragsdale EJ. Genetic regulators of a resource polyphenism interact to couple predatory morphology and behaviour. Proc Biol Sci 2024; 291:20240153. [PMID: 38835272 DOI: 10.1098/rspb.2024.0153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 04/22/2024] [Indexed: 06/06/2024] Open
Abstract
Phenotypic plasticity often requires the coordinated response of multiple traits observed individually as morphological, physiological or behavioural. The integration, and hence functionality, of this response may be influenced by whether and how these component traits share a genetic basis. In the case of polyphenism, or discrete plasticity, at least part of the environmental response is categorical, offering a simple readout for determining whether and to what degree individual components of a plastic response can be decoupled. Here, we use the nematode Pristionchus pacificus, which has a resource polyphenism allowing it to be a facultative predator of other nematodes, to understand the genetic integration of polyphenism. The behavioural and morphological consequences of perturbations to the polyphenism's genetic regulatory network show that both predatory activity and ability are strongly influenced by morphology, different axes of morphological variation are associated with different aspects of predatory behaviour, and rearing environment can decouple predatory morphology from behaviour. Further, we found that interactions between some polyphenism-modifying genes synergistically affect predatory behaviour. Our results show that the component traits of an integrated polyphenic response can be decoupled and, in principle, selected upon individually, and they suggest that multiple routes to functionally comparable phenotypes are possible.
Collapse
Affiliation(s)
- Rose M Nicholson
- Department of Biology, Indiana University , Bloomington, IN 47405, USA
| | - Nicholas A Levis
- Department of Biology, Indiana University , Bloomington, IN 47405, USA
| | - Erik J Ragsdale
- Department of Biology, Indiana University , Bloomington, IN 47405, USA
| |
Collapse
|
2
|
Hu Y, Crabtree JR, Macagno ALM, Moczek AP. Histone deacetylases regulate organ-specific growth in a horned beetle. EvoDevo 2024; 15:4. [PMID: 38575982 PMCID: PMC10996171 DOI: 10.1186/s13227-024-00223-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 03/21/2024] [Indexed: 04/06/2024] Open
Abstract
BACKGROUND Nutrient availability is among the most widespread means by which environmental variability affects developmental outcomes. Because almost all cells within an individual organism share the same genome, structure-specific growth responses must result from changes in gene regulation. Earlier work suggested that histone deacetylases (HDACs) may serve as epigenetic regulators linking nutritional conditions to trait-specific development. Here we expand on this work by assessing the function of diverse HDACs in the structure-specific growth of both sex-shared and sex-specific traits including evolutionarily novel structures in the horned dung beetle Onthophagus taurus. RESULTS We identified five HDAC members whose downregulation yielded highly variable mortality depending on which HDAC member was targeted. We then show that HDAC1, 3, and 4 operate in both a gene- and trait-specific manner in the regulation of nutrition-responsiveness of appendage size and shape. Specifically, HDAC 1, 3, or 4 knockdown diminished wing size similarly while leg development was differentially affected by RNAi targeting HDAC3 and HDAC4. In addition, depletion of HDAC3 transcript resulted in a more rounded shape of genitalia at the pupal stage and decreased the length of adult aedeagus across all body sizes. Most importantly, we find that HDAC3 and HDAC4 pattern the morphology and regulate the scaling of evolutionarily novel head and thoracic horns as a function of nutritional variation. CONCLUSION Collectively, our results suggest that both functional overlap and division of labor among HDAC members contribute to morphological diversification of both conventional and recently evolved appendages. More generally, our work raises the possibility that HDAC-mediated scaling relationships and their evolution may underpin morphological diversification within and across insect species broadly.
Collapse
Affiliation(s)
- Yonggang Hu
- Department of Biology, Indiana University, 915 East 3rd Street, Bloomington, IN, 47405, USA.
- State Key Laboratory of Resource Insects, Institute of Sericulture and Systems Biology, Southwest University, No.2 Tiansheng Road, Beibei District, Chongqing, 400715, China.
| | - Jordan R Crabtree
- Department of Biology, Indiana University, 915 East 3rd Street, Bloomington, IN, 47405, USA
| | - Anna L M Macagno
- Department of Biology, Indiana University, 915 East 3rd Street, Bloomington, IN, 47405, USA
- Biostatistics Consulting Center, Department of Epidemiology and Biostatistics, School of Public Health Bloomington, Indiana University, 2719 E. 10th Street, Bloomington, IN, 47405, USA
| | - Armin P Moczek
- Department of Biology, Indiana University, 915 East 3rd Street, Bloomington, IN, 47405, USA
| |
Collapse
|
3
|
Rohner PT, Hu Y, Moczek AP. Utilizing geometric morphometrics to investigate gene function during organ growth: Insights through the study of beetle horn shape allometry. Evol Dev 2024; 26:e12464. [PMID: 38041612 DOI: 10.1111/ede.12464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 10/05/2023] [Accepted: 11/15/2023] [Indexed: 12/03/2023]
Abstract
Static allometry is a major component of morphological variation. Much of the literature on the development of allometry investigates how functional perturbations of diverse pathways affect the relationship between trait size and body size. Often, this is done with the explicit objective to identify developmental mechanisms that enable the sensing of organ size and the regulation of relative growth. However, changes in relative trait size can also be brought about by a range of other distinctly different developmental processes, such as changes in patterning or tissue folding, yet standard univariate biometric approaches are usually unable to distinguish among alternative explanations. Here, we utilize geometric morphometrics to investigate the degree to which functional genetic manipulations known to affect the size of dung beetle horns also recapitulate the effect of horn shape allometry. We reasoned that the knockdown phenotypes of pathways governing relative growth should closely resemble shape variation induced by natural allometric variation. In contrast, we predicted that if genes primarily affect alternative developmental processes, knockdown effects should align poorly with shape allometry. We find that the knockdown effects of several genes (e.g., doublesex, Foxo) indeed closely aligned with shape allometry, indicating that their corresponding pathways may indeed function primarily in the regulation of relative trait growth. In contrast, other knockdown effects (e.g., Distal-less, dachs) failed to align with allometry, implicating these pathways in potentially scaling-independent processes. Our findings moderate the interpretation of studies focusing on trait length and highlight the usefulness of multivariate approaches to study allometry and phenotypic plasticity.
Collapse
Affiliation(s)
- Patrick T Rohner
- Department of Biology, Indiana University, Bloomington, Indiana, USA
- Department of Ecology, Behavior, and Evolution, University of California San Diego, La Jolla, California, USA
| | - Yonggang Hu
- Department of Biology, Indiana University, Bloomington, Indiana, USA
- State Key Laboratory of Silkworm Genome Biology, Institute of Sericulture and Systems Biology, Southwest University, Chongqing, China
| | - Armin P Moczek
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| |
Collapse
|
4
|
Rohner PT, Moczek AP. Vertically inherited microbiota and environment-modifying behaviors indirectly shape the exaggeration of secondary sexual traits in the gazelle dung beetle. Ecol Evol 2023; 13:e10666. [PMID: 37915805 PMCID: PMC10616735 DOI: 10.1002/ece3.10666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 10/05/2023] [Accepted: 10/13/2023] [Indexed: 11/03/2023] Open
Abstract
Many organisms actively manipulate the environment in ways that feed back on their own development, a process referred to as developmental niche construction. Yet, the role that constructed biotic and abiotic environments play in shaping phenotypic variation and its evolution is insufficiently understood. Here, we assess whether environmental modifications made by developing dung beetles impact the environment-sensitive expression of secondary sexual traits. Gazelle dung beetles both physically modify their ontogenetic environment and structure their biotic interactions through the vertical inheritance of microbial symbionts. By experimentally eliminating (i) physical environmental modifications and (ii) the vertical inheritance of microbes, we assess the degree to which (sym)biotic and physical environmental modifications shape the exaggeration of several traits varying in their degree and direction of sexual dimorphism. We expected the experimental reduction of a larva's ability to shape its environment to affect trait size and scaling, especially for traits that are sexually dimorphic and environmentally plastic. We find that compromised developmental niche construction indeed shapes sexual dimorphism in overall body size and the absolute sizes of male-limited exaggerated head horns, the strongly sexually dimorphic fore tibia length and width, as well as the weakly dimorphic elytron length and width. This suggests that environmental modifications affect sex-specific phenotypic variation in functional traits. However, most of these effects can be attributed to nutrition-dependent plasticity in size and non-isometric trait scaling rather than body-size-independent effects on the developmental regulation of trait size. Our findings suggest that the reciprocal relationship between developing organisms, their symbionts, and their environment can have considerable impacts on sexual dimorphism and functional morphology.
Collapse
Affiliation(s)
- Patrick T. Rohner
- Department of BiologyIndiana University BloomingtonBloomingtonIndianaUSA
- Department of Ecology, Behavior and EvolutionUniversity of California, San DiegoLa JollaCaliforniaUSA
| | - Armin P. Moczek
- Department of BiologyIndiana University BloomingtonBloomingtonIndianaUSA
| |
Collapse
|
5
|
Rohner PT, Casasa S, Moczek AP. Assessing the evolutionary lability of insulin signalling in the regulation of nutritional plasticity across traits and species of horned dung beetles. J Evol Biol 2023; 36:1641-1648. [PMID: 37885148 DOI: 10.1111/jeb.14240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 07/20/2023] [Accepted: 07/28/2023] [Indexed: 10/28/2023]
Abstract
Nutrition-dependent growth of sexual traits is a major contributor to phenotypic diversity, and a large body of research documents insulin signalling as a major regulator of nutritional plasticity. However, findings across studies raise the possibility that the role of individual components within the insulin signalling pathway diverges in function among traits and taxa. Here, we use RNAi-mediated transcript depletion in the gazelle dung beetle to investigate the functions of forkhead box O (Foxo) and two paralogs of the insulin receptor (InR1 and InR2) in shaping nutritional plasticity in polyphenic male head horns, exaggerated fore legs, and weakly nutrition-responsive genitalia. Our functional genetic manipulations led to three main findings: FoxoRNAi reduced the length of exaggerated head horns in large males, while neither InR1 nor InR2 knock-downs resulted in measurable horn phenotypes. These results are similar to those documented previously for another dung beetle (Onthophagus taurus), but in stark contrast to findings in rhinoceros beetles. Secondly, knockdown of Foxo, InR1, and InR2 led to an increase in the intercept or slope of the scaling relationship of genitalia size. These findings are in contrast even to results documented previously for O. taurus. Lastly, while FoxoRNAi reduces male forelegs in D. gazella and O. taurus, the effects of InR1 and InR2 knockdowns diverged across dung beetle species. Our results add to the growing body of literature indicating that despite insulin signalling's conserved role as a regulator of nutritional plasticity, the functions of its components may diversify among traits and species, potentially fuelling the evolution of scaling relationships.
Collapse
Affiliation(s)
- Patrick T Rohner
- Department of Ecology, Behavior, and Evolution, University of California San Diego, San Diego, California, USA
- Department of Biology, Indiana University Bloomington, Bloomington, Indiana, USA
| | - Sofia Casasa
- Department of Biology, Boston University, Boston, Massachusetts, USA
| | - Armin P Moczek
- Department of Biology, Indiana University Bloomington, Bloomington, Indiana, USA
| |
Collapse
|
6
|
Nadolski EM, Moczek AP. Promises and limits of an agency perspective in evolutionary developmental biology. Evol Dev 2023; 25:371-392. [PMID: 37038309 DOI: 10.1111/ede.12432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 01/23/2023] [Accepted: 03/02/2023] [Indexed: 04/12/2023]
Abstract
An agent-based perspective in the study of complex systems is well established in diverse disciplines, yet is only beginning to be applied to evolutionary developmental biology. In this essay, we begin by defining agency and associated terminology formally. We then explore the assumptions and predictions of an agency perspective, apply these to select processes and key concept areas relevant to practitioners of evolutionary developmental biology, and consider the potential epistemic roles that an agency perspective might play in evo devo. Throughout, we discuss evidence supportive of agential dynamics in biological systems relevant to evo devo and explore where agency thinking may enrich the explanatory reach of research efforts in evolutionary developmental biology.
Collapse
Affiliation(s)
- Erica M Nadolski
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | - Armin P Moczek
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| |
Collapse
|
7
|
Price PD, Parkus SM, Wright AE. Recent progress in understanding the genomic architecture of sexual conflict. Curr Opin Genet Dev 2023; 80:102047. [PMID: 37163877 DOI: 10.1016/j.gde.2023.102047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/02/2023] [Accepted: 04/02/2023] [Indexed: 05/12/2023]
Abstract
Genomic conflict between the sexes over shared traits is widely assumed to be resolved through the evolution of sex-biased expression and the subsequent emergence of sexually dimorphic phenotypes. However, while there is support for a broad relationship between genome-wide patterns of expression level and sexual conflict, recent studies suggest that sex differences in the nature and strength of interactions between loci are instead key to conflict resolution. Furthermore, the advent of new technologies for measuring and perturbing expression means we now have much more power to detect genomic signatures of sexual conflict. Here, we review our current understanding of the genomic architecture of sexual conflict in the light of these new studies and highlight the potential for novel approaches to address outstanding knowledge gaps.
Collapse
Affiliation(s)
- Peter D Price
- Ecology and Evolutionary Biology, School of Biosciences, University of Sheffield, United Kingdom. https://twitter.com/@PeterDPrice
| | - Sylvie M Parkus
- Ecology and Evolutionary Biology, School of Biosciences, University of Sheffield, United Kingdom
| | - Alison E Wright
- Ecology and Evolutionary Biology, School of Biosciences, University of Sheffield, United Kingdom.
| |
Collapse
|
8
|
Rohner PT, Hu Y, Moczek AP. Developmental bias in the evolution and plasticity of beetle horn shape. Proc Biol Sci 2022; 289:20221441. [PMID: 36168764 PMCID: PMC9515630 DOI: 10.1098/rspb.2022.1441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 09/02/2022] [Indexed: 11/12/2022] Open
Abstract
The degree to which developmental systems bias the phenotypic effects of environmental and genetic variation, and how these biases affect evolution, is subject to much debate. Here, we assess whether developmental variability in beetle horn shape aligns with the phenotypic effects of plasticity and evolutionary divergence, yielding three salient results. First, we find that most pathways previously shown to regulate horn length also affect shape. Second, we find that the phenotypic effects of manipulating divergent developmental pathways are correlated with each other as well as multivariate fluctuating asymmetry-a measure of developmental variability. Third, these effects further aligned with thermal plasticity, population differences and macroevolutionary divergence between sister taxa and more distantly related species. Collectively, our results support the hypothesis that changes in horn shape-whether brought about by environmentally plastic responses, functional manipulations or evolutionary divergences-converge along 'developmental lines of least resistance', i.e. are biased by the developmental system underpinning horn shape.
Collapse
Affiliation(s)
- Patrick T. Rohner
- Department of Biology, Indiana University Bloomington, Bloomington, IN 47405, USA
| | - Yonggang Hu
- Department of Biology, Indiana University Bloomington, Bloomington, IN 47405, USA
- State Key Laboratory of Silkworm Genome Biology, Institute of Sericulture and Systems Biology, Southwest University, Chongqing 400715, People's Republic of China
| | - Armin P. Moczek
- Department of Biology, Indiana University Bloomington, Bloomington, IN 47405, USA
| |
Collapse
|
9
|
Gao JJ, Barmina O, Thompson A, Kim BY, Suvorov A, Tanaka K, Watabe H, Toda MJ, Chen JM, Katoh TK, Kopp A. Secondary reversion to sexual monomorphism associated with tissue-specific loss of doublesex expression. Evolution 2022; 76:2089-2104. [PMID: 35841603 DOI: 10.1111/evo.14564] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 06/23/2022] [Accepted: 06/27/2022] [Indexed: 01/22/2023]
Abstract
Animal evolution is characterized by frequent turnover of sexually dimorphic traits-new sex-specific characters are gained, and some ancestral sex-specific characters are lost, in many lineages. In insects, sexual differentiation is predominantly cell autonomous and depends on the expression of the doublesex (dsx) transcription factor. In most cases, cells that transcribe dsx have the potential to undergo sex-specific differentiation, while those that lack dsx expression do not. Consistent with this mode of development, comparative research has shown that the origin of new sex-specific traits can be associated with the origin of new spatial domains of dsx expression. In this report, we examine the opposite situation-a secondary loss of the sex comb, a male-specific grasping structure that develops on the front legs of some drosophilid species. We show that while the origin of the sex comb is linked to an evolutionary gain of dsx expression in the leg, sex comb loss in a newly identified species of Lordiphosa (Drosophilidae) is associated with a secondary loss of dsx expression. We discuss how the developmental control of sexual dimorphism affects the mechanisms by which sex-specific traits can evolve.
Collapse
Affiliation(s)
- Jian-Jun Gao
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, China.,State Key Laboratory for Conservation and Utilization of Bioresources in Yunnan, Yunnan University, China
| | - Olga Barmina
- Department of Evolution and Ecology, University of California Davis, Davis, CA, 95616, USA
| | - Ammon Thompson
- Department of Evolution and Ecology, University of California Davis, Davis, CA, 95616, USA
| | - Bernard Y Kim
- Department of Biology, Stanford University, Stanford, CA, 94305, USA
| | - Anton Suvorov
- Department of Genetics, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Kohtaro Tanaka
- Department of Evolution and Ecology, University of California Davis, Davis, CA, 95616, USA
| | - Hideaki Watabe
- The Hokkaido University Museum, Kita-10, Nishi-8, Kitaku, Sapporo, 060-0810, Japan
| | - Masanori J Toda
- The Hokkaido University Museum, Kita-10, Nishi-8, Kitaku, Sapporo, 060-0810, Japan
| | - Ji-Min Chen
- State Key Laboratory for Conservation and Utilization of Bioresources in Yunnan, Yunnan University, China
| | - Takehiro K Katoh
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, China
| | - Artyom Kopp
- Department of Evolution and Ecology, University of California Davis, Davis, CA, 95616, USA
| |
Collapse
|
10
|
Rohner PT. A role for sex-determination genes in life history evolution? Doublesex mediates sexual size dimorphism in the gazelle dung beetle. J Evol Biol 2021; 34:1326-1332. [PMID: 34075658 DOI: 10.1111/jeb.13877] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 04/06/2021] [Accepted: 05/09/2021] [Indexed: 02/06/2023]
Abstract
An organism's fitness depends strongly on its age and size at maturation. Although the evolutionary forces acting on these critical life history traits have been heavily scrutinized, the developmental mechanisms underpinning intraspecific variation in adult size and development time remain much less well-understood. Using RNA interference, I here show that the highly conserved sex-determination gene doublesex (dsx) mediates sexual size dimorphism (SSD) in the gazelle dung beetle Digitonthophagus gazella. Because doublesex undergoes sex-specific splicing and sex-limited isoforms regulate different target genes, this suggests that dsx contributes to the resolution of intralocus sexual conflict in body size. However, these results contrast with previous studies demonstrating that dsx does not affect body size or SSD in Drosophila. This indicates that intraspecific body size variation is underlain by contrasting developmental mechanisms in different insect lineages. Furthermore, although male D. gazella have a longer development time than females, sexual bimaturism was not affected by dsx expression knockdown. In addition, and in contrast to secondary sexual morphology, dsx did not significantly affect nutritional plasticity in life history. Taken together, these findings indicate that dsx signalling contributes to intraspecific life history variation but that dsx's function in mediating sexual dimorphism in life history differs among traits and species. More generally, these findings suggest that genes ancestrally tasked with sex determination have been co-opted into the developmental regulation of life history traits and may represent an underappreciated mechanism of life history evolution.
Collapse
|