tartan underlies the evolution of Drosophila male genital morphology
| Autor: | Pedro Gaspar, Alistair P. McGregor, Maike Kittelmann, Alexander Payne, Kentaro M. Tanaka, Amber Blogg, Javier Figueras Jimenez, Maria D. S. Nunes, Joanna F. D. Hagen, Cláudia C. Mendes |
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| Rok vydání: | 2019 |
| Předmět: |
0106 biological sciences
0301 basic medicine Multidisciplinary biology Evolution genitalia Biological Sciences Clasper biology.organism_classification Bristle 010603 evolutionary biology 01 natural sciences Drosophila mauritiana Phenotype 03 medical and health sciences 030104 developmental biology Evolutionary biology Sexual selection genetics Drosophila Allele development Mauritiana Gene |
| Zdroj: | Proceedings of the National Academy of Sciences of the United States of America |
| ISSN: | 1091-6490 0027-8424 |
| Popis: | Significance The morphology of male genitalia evolves rapidly, probably driven by sexual selection. However, little is known about the genes underlying genitalia differences between species. Identifying these genes is key to understanding how sexual selection acts to produce rapid phenotypic change. We have found that the gene tartan underlies differences between male Drosophila mauritiana and Drosophila simulans in the size and bristle number of the claspers—genital projections that grasp the female during copulation. Moreover, since tartan encodes a protein that is involved in cell interactions, this may represent an alternative developmental mechanism for morphological change. Therefore, our study provides insights into the genetic and developmental bases for the rapid evolution of male genitalia and organ size more generally. Male genital structures are among the most rapidly evolving morphological traits and are often the only features that can distinguish closely related species. This process is thought to be driven by sexual selection and may reinforce species separation. However, while the genetic bases of many phenotypic differences have been identified, we still lack knowledge about the genes underlying evolutionary differences in male genital organs and organ size more generally. The claspers (surstyli) are periphallic structures that play an important role in copulation in insects. Here, we show that divergence in clasper size and bristle number between Drosophila mauritiana and Drosophila simulans is caused by evolutionary changes in tartan (trn), which encodes a transmembrane leucine-rich repeat domain protein that mediates cell–cell interactions and affinity. There are no fixed amino acid differences in trn between D. mauritiana and D. simulans, but differences in the expression of this gene in developing genitalia suggest that cis-regulatory changes in trn underlie the evolution of clasper morphology in these species. Finally, analyses of reciprocal hemizygotes that are genetically identical, except for the species from which the functional allele of trn originates, determined that the trn allele of D. mauritiana specifies larger claspers with more bristles than the allele of D. simulans. Therefore, we have identified a gene underlying evolutionary change in the size of a male genital organ, which will help to better understand not only the rapid diversification of these structures, but also the regulation and evolution of organ size more broadly. |
| Databáze: | OpenAIRE |
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