1
|
Goldenberg J, Bisschop K, Bruni G, Di Nicola MR, Banfi F, Faraone FP. Melanin-based color variation in response to changing climates in snakes. Ecol Evol 2024; 14:e11627. [PMID: 38952653 PMCID: PMC11213819 DOI: 10.1002/ece3.11627] [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: 02/17/2024] [Revised: 05/30/2024] [Accepted: 06/10/2024] [Indexed: 07/03/2024] Open
Abstract
Melanism, the process of heavier melanin deposition, can interact with climate variation at both micro and macro scales, ultimately influencing color evolution in organisms. While the ecological processes regulating melanin production in relation to climate have been extensively studied, intraspecific variations of melanism are seldom considered. Such scientific gap hampers our understanding of how species adapt to rapidly changing climates. For example, dark coloration may lead to higher heat absorption and be advantageous in cool climates, but also in hot environments as a UV or antimicrobial protection mechanism. To disentangle such opposing predictions, here we examined the effect of climate on shaping melanism variation in 150 barred grass snakes (Natrix helvetica) and 383 green whip snakes (Hierophis viridiflavus) across Italy. By utilizing melanistic morphs (charcoal and picturata in N. helvetica, charcoal and abundistic in H. viridiflavus) and compiling observations from 2002 to 2021, we predicted that charcoal morphs in H. viridiflavus would optimize heat absorption in cold environments, while offering protection from excessive UV radiation in N. helvetica within warm habitats; whereas picturata and abundistic morphs would thrive in humid environments, which naturally have a denser vegetation and wetter substrates producing darker ambient light, thus providing concealment advantages. While picturata and abundistic morphs did not align with our initial humidity expectations, the charcoal morph in N. helvetica is associated with UV environments, suggesting protection mechanisms against damaging solar radiation. H. viridiflavus is associated with high precipitations, which might offer antimicrobial protection. Overall, our results provide insights into the correlations between melanin-based color morphs and climate variables in snake populations. While suggestive of potential adaptive responses, future research should delve deeper into the underlying mechanisms regulating this relationship.
Collapse
Affiliation(s)
- J. Goldenberg
- Division of Biodiversity and Evolution, Department of BiologyLund UniversityLundSweden
- Evolution and Optics of Nanostructures Group, Department of BiologyGhent UniversityGhentBelgium
| | - K. Bisschop
- Division of Biodiversity and Evolution, Department of BiologyLund UniversityLundSweden
- Laboratory of Aquatic BiologyKU Leuven KulakKortrijkBelgium
- Terrestrial Ecology Unit, Department of BiologyGhent UniversityGhentBelgium
| | - G. Bruni
- Independent Researcher, Viale Palmiro TogliattiSesto FiorentinoFlorenceItaly
| | - M. R. Di Nicola
- Faculty of Veterinary Medicine, Department of Pathobiology, Pharmacology and Zoological Medicine, Wildlife Health GhentGhent UniversityMerelbekeBelgium
- Unit of Dermatology and CosmetologyIRCCS San Raffaele HospitalMilanItaly
| | - F. Banfi
- Laboratory of Functional Morphology, Department of BiologyUniversity of AntwerpWilrijkBelgium
| | - F. P. Faraone
- Dipartimento Scienze e Tecnologie Biologiche, Chimiche e FarmaceuticheUniversity of PalermoPalermoItaly
| |
Collapse
|
2
|
Morita S, Shibata TF, Nishiyama T, Kobayashi Y, Yamaguchi K, Toga K, Ohde T, Gotoh H, Kojima T, Weber JN, Salvemini M, Bino T, Mase M, Nakata M, Mori T, Mori S, Cornette R, Sakura K, Lavine LC, Emlen DJ, Niimi T, Shigenobu S. The draft genome sequence of the Japanese rhinoceros beetle Trypoxylus dichotomus septentrionalis towards an understanding of horn formation. Sci Rep 2023; 13:8735. [PMID: 37253792 DOI: 10.1038/s41598-023-35246-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Accepted: 05/15/2023] [Indexed: 06/01/2023] Open
Abstract
The Japanese rhinoceros beetle Trypoxylus dichotomus is a giant beetle with distinctive exaggerated horns present on the head and prothoracic regions of the male. T. dichotomus has been used as a research model in various fields such as evolutionary developmental biology, ecology, ethology, biomimetics, and drug discovery. In this study, de novo assembly of 615 Mb, representing 80% of the genome estimated by flow cytometry, was obtained using the 10 × Chromium platform. The scaffold N50 length of the genome assembly was 8.02 Mb, with repetitive elements predicted to comprise 49.5% of the assembly. In total, 23,987 protein-coding genes were predicted in the genome. In addition, de novo assembly of the mitochondrial genome yielded a contig of 20,217 bp. We also analyzed the transcriptome by generating 16 RNA-seq libraries from a variety of tissues of both sexes and developmental stages, which allowed us to identify 13 co-expressed gene modules. We focused on the genes related to horn formation and obtained new insights into the evolution of the gene repertoire and sexual dimorphism as exemplified by the sex-specific splicing pattern of the doublesex gene. This genomic information will be an excellent resource for further functional and evolutionary analyses, including the evolutionary origin and genetic regulation of beetle horns and the molecular mechanisms underlying sexual dimorphism.
Collapse
Grants
- 23128505, 25128706, 16H01452, 18H04766, 20H04933, 20H05944, 17H06384, 22128008, 19K16181, 21K15135 Japan Society for the Promotion of Science
- 23128505, 25128706, 16H01452, 18H04766, 20H04933, 20H05944, 17H06384, 22128008, 19K16181, 21K15135 Japan Society for the Promotion of Science
- 23128505, 25128706, 16H01452, 18H04766, 20H04933, 20H05944, 17H06384, 22128008, 19K16181, 21K15135 Japan Society for the Promotion of Science
- 23128505, 25128706, 16H01452, 18H04766, 20H04933, 20H05944, 17H06384, 22128008, 19K16181, 21K15135 Japan Society for the Promotion of Science
- IOS-1456133 National Science Foundation
- IOS-1456133 National Science Foundation
Collapse
Affiliation(s)
- Shinichi Morita
- Division of Evolutionary Developmental Biology, National Institute for Basic Biology, Okazaki, Japan
- Department of Basic Biology, School of Life Science, The Graduate University for Advanced Studies, SOKENDAI, Okazaki, Japan
| | - Tomoko F Shibata
- Division of Evolutionary Biology, National Institute for Basic Biology, Okazaki, Japan
| | - Tomoaki Nishiyama
- Division of Integrated Omics Research, Research Center for Experimental Modeling of Human Disease, Kanazawa University, Kanazawa, Japan
| | - Yuuki Kobayashi
- Laboratory of Evolutionary Genomics, National Institute for Basic Biology, Okazaki, Japan
| | - Katsushi Yamaguchi
- Trans-Omics Facility, National Institute for Basic Biology, Okazaki, Japan
| | - Kouhei Toga
- Laboratory of Sericulture and Entomoresources, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
- URA Division, Office of Research and Academia-Government-Community Collaboration, Hiroshima University, Hiroshima, Japan
| | - Takahiro Ohde
- Division of Evolutionary Developmental Biology, National Institute for Basic Biology, Okazaki, Japan
- Laboratory of Sericulture and Entomoresources, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
- Department of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Hiroki Gotoh
- Laboratory of Sericulture and Entomoresources, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
- Department of Biological Science, Faculty of Science, Shizuoka University, Shizuoka, Japan
| | - Takaaki Kojima
- Laboratory of Molecular Biotechnology, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
- Department of Agrobiological Resources, Faculty of Agriculture, Meijo University, Nagoya, Japan
| | - Jesse N Weber
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, USA
| | - Marco Salvemini
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Takahiro Bino
- Trans-Omics Facility, National Institute for Basic Biology, Okazaki, Japan
| | - Mutsuki Mase
- Division of Evolutionary Developmental Biology, National Institute for Basic Biology, Okazaki, Japan
- Laboratory of Sericulture and Entomoresources, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Moe Nakata
- Laboratory of Sericulture and Entomoresources, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Tomoko Mori
- Trans-Omics Facility, National Institute for Basic Biology, Okazaki, Japan
| | - Shogo Mori
- Trans-Omics Facility, National Institute for Basic Biology, Okazaki, Japan
| | - Richard Cornette
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, Tsukuba, Japan
| | - Kazuki Sakura
- Division of Evolutionary Developmental Biology, National Institute for Basic Biology, Okazaki, Japan
| | - Laura C Lavine
- Department of Entomology, Washington State University, Pullman, WA, USA
| | - Douglas J Emlen
- Division of Biological Sciences, The University of Montana, Missoula, MT, USA
| | - Teruyuki Niimi
- Division of Evolutionary Developmental Biology, National Institute for Basic Biology, Okazaki, Japan.
- Department of Basic Biology, School of Life Science, The Graduate University for Advanced Studies, SOKENDAI, Okazaki, Japan.
- Laboratory of Sericulture and Entomoresources, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan.
| | - Shuji Shigenobu
- Department of Basic Biology, School of Life Science, The Graduate University for Advanced Studies, SOKENDAI, Okazaki, Japan.
- Laboratory of Evolutionary Genomics, National Institute for Basic Biology, Okazaki, Japan.
- Trans-Omics Facility, National Institute for Basic Biology, Okazaki, Japan.
| |
Collapse
|
3
|
Li X, Zhao MH, Tian MM, Zhao J, Cai WL, Hua HX. An InR/mir-9a/NlUbx regulatory cascade regulates wing diphenism in brown planthoppers. INSECT SCIENCE 2021; 28:1300-1313. [PMID: 32935926 DOI: 10.1111/1744-7917.12872] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/09/2020] [Accepted: 08/26/2020] [Indexed: 06/11/2023]
Abstract
Wing polymorphism significantly contributes to the ecological success of some insect species. For example, the brown planthopper (BPH) Nilaparvata lugens, which is one of the most destructive rice pests in Asia, can develop into either highly mobile long-winged or highly fecund short-winged adult morphs. A recent study reported a highly provocative result that the Hox gene Ultrabithorax (Ubx) is expressed in BPH forewings and showed that this wing development gene is differentially expressed in nymphs that develop into long-winged versus short-winged morphs. Here, we found that Ubx may be a mir-9a target, and used dual luciferase reporter assays and injected micro RNA (miRNA) mimics and inhibitors to confirm the interactions between mir-9a and NlUbx. We measured the mir-9a and NlUbx expression profiles in nymphs and found that the expression of these two biomolecules was negatively correlated. By rearing BPH nymphs on host rice plants with different nutritional status, we were able to characterize a regulatory cascade between insulin receptor genes, mir-9a, and NlUbx that regulate wing length in BPHs. When host quality was low, NlInR1 expression in the nymph terga increased and NlInR2 expression decreased; this led to a higher mir-9a level, which in turn reduced the NlUbx transcript level and ultimately resulted in longer wing lengths. Beyond extending our understanding of the interplay between host plant status and genetic events that modulate polymorphism, we demonstrated both the upstream signal and miRNA-based regulatory mechanism that control Ubx expression in BPH forewings.
Collapse
Affiliation(s)
- Xiang Li
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Mu-Hua Zhao
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Miao-Miao Tian
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Jing Zhao
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Wan-Lun Cai
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Hong-Xia Hua
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| |
Collapse
|
4
|
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
|
5
|
Smallegange IM, Rhebergen FT, Stewart KA. Cross-level considerations for explaining selection pressures and the maintenance of genetic variation in condition-dependent male morphs. CURRENT OPINION IN INSECT SCIENCE 2019; 36:66-73. [PMID: 31499417 DOI: 10.1016/j.cois.2019.08.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 07/11/2019] [Accepted: 08/08/2019] [Indexed: 06/10/2023]
Abstract
Condition-dependent expression of alternative male morphologies (AMMs) exists in many arthropods. Understanding their coexistence requires answering (at least) two questions: (i) what are the ecological selection pressures that maintain condition-dependent plasticity of AMM expression, and (ii) what maintains the associated genetic variation? Focusing on acarid mites, we show that the questions should not be conflated. We argue how, instead, answers should be sought by testing phenotype-level (question 1) or genotype-level (question 2) hypotheses. We illustrate that energy allocation restrictions and physiological trade-offs are likely to play a crucial role in AMM expression in acarid mites. We thus conclude that these aspects require specific attention in identifying selection pressures maintaining condition-dependent plasticity, and evolutionary processes that maintain genetic variation in condition-dependent phenotypic plasticity.
Collapse
Affiliation(s)
- Isabel M Smallegange
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, PO Box 94240, 1090 GE Amsterdam, The Netherlands.
| | - Flor T Rhebergen
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, PO Box 94240, 1090 GE Amsterdam, The Netherlands
| | - Kathryn A Stewart
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, PO Box 94240, 1090 GE Amsterdam, The Netherlands
| |
Collapse
|
6
|
Freitak D, Tammaru T, Sandre S, Meister H, Esperk T. Longer life span is associated with elevated immune activity in a seasonally polyphenic butterfly. J Evol Biol 2019; 32:653-665. [PMID: 30903723 PMCID: PMC6850579 DOI: 10.1111/jeb.13445] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 02/13/2019] [Accepted: 03/06/2019] [Indexed: 12/13/2022]
Abstract
Seasonal polyphenism constitutes a specific type of phenotypic plasticity in which short-lived organisms produce different phenotypes in different times of the year. Seasonal generations of such species frequently differ in their overall lifespan and in the values of traits closely related to fitness. Seasonal polyphenisms provide thus excellent, albeit underused model systems for studying trade-offs between life-history traits. Here, we compare immunological parameters between the two generations of the European map butterfly (Araschnia levana), a well-known example of a seasonally polyphenic species. To reveal possible costs of immune defence, we also examine the concurrent differences in several life-history traits. Both in laboratory experiments and in the field, last instar larvae heading towards the diapause (overwintering) had higher levels of both phenoloxidase (PO) activity and lytic activity than directly developing individuals. These results suggest that individuals from the diapausing generation with much longer juvenile (pupal) period invest more in their immune system than those from the short-living directly developing generation. The revealed negative correlation between pupal mass and PO activity may be one of the reasons why, in this species, the diapausing generation has a smaller body size than the directly developing generation. Immunological parameters may thus well mediate trade-offs between body size-related traits.
Collapse
Affiliation(s)
- Dalial Freitak
- Faculty of Biological and Environmental SciencesOrganismal and Evolutionary Biology Research ProgrammeHelsinkiFinland
- Division of ZoologyInstitute of BiologyUniversity of GrazGrazAustria
| | - Toomas Tammaru
- Department of ZoologyInstitute of Ecology and Earth SciencesUniversity of TartuTartuEstonia
| | - Siiri‐Lii Sandre
- Department of ZoologyInstitute of Ecology and Earth SciencesUniversity of TartuTartuEstonia
| | - Hendrik Meister
- Department of ZoologyInstitute of Ecology and Earth SciencesUniversity of TartuTartuEstonia
| | - Toomas Esperk
- Department of ZoologyInstitute of Ecology and Earth SciencesUniversity of TartuTartuEstonia
| |
Collapse
|
7
|
Schneider RF, Meyer A. How plasticity, genetic assimilation and cryptic genetic variation may contribute to adaptive radiations. Mol Ecol 2016; 26:330-350. [PMID: 27747962 DOI: 10.1111/mec.13880] [Citation(s) in RCA: 104] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 09/30/2016] [Accepted: 10/07/2016] [Indexed: 12/13/2022]
Abstract
There is increasing evidence that phenotypic plasticity can promote population divergence by facilitating phenotypic diversification and, eventually, genetic divergence. When a 'plastic' population colonizes a new habitat, it has the possibility to occupy multiple niches by expressing several distinct phenotypes. These initially reflect the population's plastic range but may later become genetically fixed by selection via the process of 'genetic assimilation' (GA). Through this process multiple specialized sister lineages can arise that share a common plastic ancestor - the 'flexible stem'. Here, we review possible molecular mechanisms through which natural selection could fix an initially plastic trait during GA. These mechanisms could also explain how GA may contribute to cryptic genetic variation that can subsequently be coopted into other phenotypes or traits, but also lead to nonadaptive responses. We outline the predicted patterns of genetic and transcriptional divergence accompanying flexible stem radiations. The analysis of such patterns of (retained) adaptive and nonadaptive plastic responses within and across radiating lineages can inform on the state of ongoing GA. We conclude that, depending on the stability of the environment, the molecular architecture underlying plastic traits can facilitate diversification, followed by fixation and consolidation of an adaptive phenotype and degeneration of nonadaptive ones. Additionally, the process of GA may increase the cryptic genetic variation of populations, which on one hand may serve as substrate for evolution, but on another may be responsible for nonadaptive responses that consolidate local allopatry and thus reproductive isolation.
Collapse
Affiliation(s)
- Ralf F Schneider
- Lehrstuhl für Zoologie und Evolutionsbiologie, Department of Biology, University of Konstanz, Universitaetstrasse 10, 78457, Konstanz, Germany
| | - Axel Meyer
- Lehrstuhl für Zoologie und Evolutionsbiologie, Department of Biology, University of Konstanz, Universitaetstrasse 10, 78457, Konstanz, Germany
| |
Collapse
|
8
|
Gotoh H, Ishiguro M, Nishikawa H, Morita S, Okada K, Miyatake T, Yaginuma T, Niimi T. Molecular cloning and functional characterization of the sex-determination gene doublesex in the sexually dimorphic broad-horned beetle Gnatocerus cornutus (Coleoptera, Tenebrionidae). Sci Rep 2016; 6:29337. [PMID: 27404087 PMCID: PMC4941388 DOI: 10.1038/srep29337] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 06/13/2016] [Indexed: 11/08/2022] Open
Abstract
Various types of weapon traits found in insect order Coleoptera are known as outstanding examples of sexually selected exaggerated characters. It is known that the sex determination gene doublesex (dsx) plays a significant role in sex-specific expression of weapon traits in various beetles belonging to the superfamily Scarabaeoidea. Although sex-specific weapon traits have evolved independently in various Coleopteran groups, developmental mechanisms of sex-specific expression have not been studied outside of the Scarabaeoidea. In order to test the hypothesis that dsx-dependent sex-specific expression of weapon traits is a general mechanism among the Coleoptera, we have characterized the dsx in the sexually dimorphic broad-horned beetle Gnatocerus cornutus (Tenebrionidea, Tenebirionidae). By using molecular cloning, we identified five splicing variants of Gnatocerus cornutus dsx (Gcdsx), which are predicted to code four different isoforms. We found one male-specific variant (GcDsx-M), two female-specific variants (GcDsx-FL and GcDsx-FS) and two non-sex-specific variants (correspond to a single isoform, GcDsx-C). Knockdown of all Dsx isoforms resulted in intersex phenotype both in male and female. Also, knockdown of all female-specific isoforms transformed females to intersex phenotype, while did not affect male phenotype. Our results clearly illustrate the important function of Gcdsx in determining sex-specific trait expression in both sexes.
Collapse
Affiliation(s)
- Hiroki Gotoh
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan
| | - Mai Ishiguro
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan
| | - Hideto Nishikawa
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan
| | - Shinichi Morita
- Division of Evolutionary Developmental Biology, National Institute for Basic Biology, 38, Nishigonaka, Myodaiji, Okazaki 444-8585, Japan
| | - Kensuke Okada
- Graduate School of Environmental and Life Science, Okayama University, Okayama 700-8530, Japan
| | - Takahisa Miyatake
- Graduate School of Environmental and Life Science, Okayama University, Okayama 700-8530, Japan
| | - Toshinobu Yaginuma
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan
| | - Teruyuki Niimi
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan
- Division of Evolutionary Developmental Biology, National Institute for Basic Biology, 38, Nishigonaka, Myodaiji, Okazaki 444-8585, Japan
- Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), 38 Nishigonaka, Myodaiji, Okazaki 444-8585, Japan
| |
Collapse
|
9
|
Gotoh H, Zinna RA, Warren I, DeNieu M, Niimi T, Dworkin I, Emlen DJ, Miura T, Lavine LC. Identification and functional analyses of sex determination genes in the sexually dimorphic stag beetle Cyclommatus metallifer. BMC Genomics 2016; 17:250. [PMID: 27001106 PMCID: PMC4802893 DOI: 10.1186/s12864-016-2522-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 02/24/2016] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Genes in the sex determination pathway are important regulators of sexually dimorphic animal traits, including the elaborate and exaggerated male ornaments and weapons of sexual selection. In this study, we identified and functionally analyzed members of the sex determination gene family in the golden metallic stag beetle Cyclommatus metallifer, which exhibits extreme differences in mandible size between males and females. RESULTS We constructed a C. metallifer transcriptomic database from larval and prepupal developmental stages and tissues of both males and females. Using Roche 454 pyrosequencing, we generated a de novo assembled database from a total of 1,223,516 raw reads, which resulted in 14,565 isotigs (putative transcript isoforms) contained in 10,794 isogroups (putative identified genes). We queried this database for C. metallifer conserved sex determination genes and identified 14 candidate sex determination pathway genes. We then characterized the roles of several of these genes in development of extreme sexual dimorphic traits in this species. We performed molecular expression analyses with RT-PCR and functional analyses using RNAi on three C. metallifer candidate genes--Sex-lethal (CmSxl), transformer-2 (Cmtra2), and intersex (Cmix). No differences in expression pattern were found between the sexes for any of these three genes. In the RNAi gene-knockdown experiments, we found that only the Cmix had any effect on sexually dimorphic morphology, and these mimicked the effects of Cmdsx knockdown in females. Knockdown of CmSxl had no measurable effects on stag beetle phenotype, while knockdown of Cmtra2 resulted in complete lethality at the prepupal period. These results indicate that the roles of CmSxl and Cmtra2 in the sex determination cascade are likely to have diverged in stag beetles when compared to Drosophila. Our results also suggest that Cmix has a conserved role in this pathway. In addition to those three genes, we also performed a more complete functional analysis of the C. metallifer dsx gene (Cmdsx) to identify the isoforms that regulate dimorphism more fully using exon-specific RNAi. We identified a total of 16 alternative splice variants of the Cmdsx gene that code for up to 14 separate exons. Despite the variation in RNA splice products of the Cmdsx gene, only four protein isoforms are predicted. The results of our exon-specific RNAi indicated that the essential CmDsx isoform for postembryonic male differentiation is CmDsxB, whereas postembryonic female specific differentiation is mainly regulated by CmDsxD. CONCLUSIONS Taken together, our results highlight the importance of studying the function of highly conserved sex determination pathways in numerous insect species, especially those with dramatic and exaggerated sexual dimorphism, because conservation in protein structure does not always translate into conservation in downstream function.
Collapse
Affiliation(s)
- Hiroki Gotoh
- Department of Entomology, Washington State University, Pullman, WA, 99164, USA
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido, 060-0810, Japan
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, 464-8601, Japan
| | - Robert A Zinna
- Department of Entomology, Washington State University, Pullman, WA, 99164, USA
| | - Ian Warren
- Department of Entomology, Washington State University, Pullman, WA, 99164, USA
| | - Michael DeNieu
- Department of Zoology, Michigan State University, East Lansing, MI, 48824, USA
| | - Teruyuki Niimi
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, 464-8601, Japan
- Division of Evolutionary Developmental Biology, National Institute for Basic Biology, Okazaki, Aichi, 444-8585, Japan
| | - Ian Dworkin
- Department of Zoology, Michigan State University, East Lansing, MI, 48824, USA
- Department of Biology, McMaster University, Hamilton, ONT, L8S 4K1, Canada
| | - Douglas J Emlen
- Division of Biological Sciences, University of Montana-Missoula, Missoula, MT, 59812, USA
| | - Toru Miura
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido, 060-0810, Japan
| | - Laura C Lavine
- Department of Entomology, Washington State University, Pullman, WA, 99164, USA.
| |
Collapse
|
10
|
Eco-Evo-Devo: developmental symbiosis and developmental plasticity as evolutionary agents. Nat Rev Genet 2015; 16:611-22. [PMID: 26370902 DOI: 10.1038/nrg3982] [Citation(s) in RCA: 195] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The integration of research from developmental biology and ecology into evolutionary theory has given rise to a relatively new field, ecological evolutionary developmental biology (Eco-Evo-Devo). This field integrates and organizes concepts such as developmental symbiosis, developmental plasticity, genetic accommodation, extragenic inheritance and niche construction. This Review highlights the roles that developmental symbiosis and developmental plasticity have in evolution. Developmental symbiosis can generate particular organs, can produce selectable genetic variation for the entire animal, can provide mechanisms for reproductive isolation, and may have facilitated evolutionary transitions. Developmental plasticity is crucial for generating novel phenotypes, facilitating evolutionary transitions and altered ecosystem dynamics, and promoting adaptive variation through genetic accommodation and niche construction. In emphasizing such non-genomic mechanisms of selectable and heritable variation, Eco-Evo-Devo presents a new layer of evolutionary synthesis.
Collapse
|