Sperm Cyst 'Looping': A Developmental Novelty Enabling Extreme Male Ornament Evolution
| Autor: | Zeeshan Ali Syed, Julie A. Brill, Romano Dallai, Ethan M Leef, Negar Nasirzadeh, Matthew M Hansen, Amaar Asif, Steve Dorus, Patrick M. O’Grady, Siyuan Cong, Scott Pitnick, Sarah Rice, Stephanie Nguyen |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Male
endocrine system Ecological selection QH301-705.5 Biology saltans Article Species Specificity heterochrony Testis medicine Animals Cyst Sexual Maturation Biology (General) trait diversification reproductive and urinary physiology Phylogeny energetic constraint Spermatid urogenital system life-history postcopulatory sexual selection female reproductive tract Animal Structures General Medicine medicine.disease Sperm Biological Evolution Spermatozoa spermatogenesis medicine.anatomical_structure willistoni Evolutionary biology Sexual selection Drosophila Adaptation Heterochrony Spermatogenesis |
| Zdroj: | Cells Volume 10 Issue 10 Cells, Vol 10, Iss 2762, p 2762 (2021) |
| ISSN: | 2073-4409 |
| Popis: | Postcopulatory sexual selection is credited as a principal force behind the rapid evolution of reproductive characters, often generating a pattern of correlated evolution between interacting, sex-specific traits. Because the female reproductive tract is the selective environment for sperm, one taxonomically widespread example of this pattern is the co-diversification of sperm length and female sperm-storage organ dimension. In Drosophila, having testes that are longer than the sperm they manufacture was believed to be a universal physiological constraint. Further, the energetic and time costs of developing long testes have been credited with underlying the steep evolutionary allometry of sperm length and constraining sperm length evolution in Drosophila. Here, we report on the discovery of a novel spermatogenic mechanism—sperm cyst looping—that enables males to produce relatively long sperm in short testis. This phenomenon (restricted to members of the saltans and willistoni species groups) begins early during spermatogenesis and is potentially attributable to heterochronic evolution, resulting in growth asynchrony between spermatid tails and the surrounding spermatid and somatic cyst cell membranes. By removing the allometric constraint on sperm length, this evolutionary innovation appears to have enabled males to evolve extremely long sperm for their body mass while evading delays in reproductive maturation time. On the other hand, sperm cyst looping was found to exact a cost by requiring greater total energetic investment in testes and a pronounced reduction in male lifespan. We speculate on the ecological selection pressures underlying the evolutionary origin and maintenance of this unique adaptation. |
| Databáze: | OpenAIRE |
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