Variation in female reproductive tract morphology across the reproductive cycle in the zebra finch.
| Autor: | Hurley LL; Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia., Crino OL; School of Life and Environmental Sciences, Deakin University, Burwood, VIC, Australia., Rowe M; Department of Animal Ecology, Netherlands Institute of Ecology, Wageningen, Netherlands., Griffith SC; Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia. |
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| Jazyk: | angličtina |
| Zdroj: | PeerJ [PeerJ] 2020 Nov 11; Vol. 8, pp. e10195. Date of Electronic Publication: 2020 Nov 11 (Print Publication: 2020). |
| DOI: | 10.7717/peerj.10195 |
| Abstrakt: | Background: In seasonally breeding birds, the reproductive tract undergoes a dramatic circannual cycle of recrudescence and regression, with oviduct size increasing 5-220 fold from the non-breeding to the breeding state. Opportunistically breeding birds can produce multiple clutches sequentially across an extended period in response primarily to environmental rather than seasonal cues. In the zebra finch, it has been shown that there is a significant reduction in gonadal morphology in non-breeding females. However, the scale of recrudescence and regression of reproductive tissue within a single breeding cycle is unknown and yet important to understand the cost of breeding, and the physiological readiness to breed in such flexible breeders. Methods: We examined the reproductive tissue of breeding female zebra finches at six stages in the nesting cycle from pre-breeding to fledging offspring. We quantified the wet mass of the oviduct, the volume of the largest pre-ovulatory follicle, and the total number of pre-ovulatory follicles present on the ovary. Results: Measures of the female reproductive tract were highest during nesting and laying stages and declined significantly in the later stages of the breeding cycle. Importantly, we found that the mass of reproductive tissue changes as much across a single reproductive event as that previously characterized between birds categorized as breeding and non-breeding. However, the regression of the ovary is less dramatic than that seen in seasonal breeders. This could reflect low-level maintenance of reproductive tissues in opportunistic breeders, but needs to be confirmed in wild non-breeding birds. Competing Interests: Simon C. Griffith is a PeerJ Academic Editor. The authors declare that they have no competing interests. (© 2020 Hurley et al.) |
| Databáze: | MEDLINE |
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