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Hit or Miss: Fertilization Outcomes of Natural Inseminations by Japanese Quail.

Adkins-Regan E - PLoS ONE (2015)

Bottom Line: Variation in fertilization success underlies sexual selection, yet mating does not guarantee fertilization.Both sexes gained similar numbers of fertilized eggs by mating with a second partner the next day, but males, unlike females in a previous study, did not gain by having two females to mate with at the same time.Even double inseminations often failed to fertilize any eggs, and multiple matings would be needed for an entire clutch to be fertilized with high certainty.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology and Department of Neurobiology and Behavior, Cornell University, Ithaca, New York, United States of America.

ABSTRACT
Variation in fertilization success underlies sexual selection, yet mating does not guarantee fertilization. The relationship between natural inseminations and fertilization success is essential for understanding sexual selection, yet that relationship and its underlying mechanisms are poorly understood in sperm-storing vertebrates such as birds. Here the relationship is analyzed in mating trials using Japanese quail (Coturnix japonica), which show striking variation in the fertilizing success of inseminations. Failures of males' inseminations to fertilize eggs were mainly due to failures prior to sperm-egg contact. Fertilization probabilities on any given day were unrelated to whether the female had laid an egg the previous day, arguing against stimulation of sperm release from sperm storage tubules by the events of the daily egg-laying cycle. Instead, an unfertilized egg laid between two fertilized eggs predicted a longer sperm storage interval. Both sexes gained similar numbers of fertilized eggs by mating with a second partner the next day, but males, unlike females in a previous study, did not gain by having two females to mate with at the same time. Instead, they were both behaviorally and sperm limited, whereas females gain by mating twice in quick succession. Even double inseminations often failed to fertilize any eggs, and multiple matings would be needed for an entire clutch to be fertilized with high certainty. Paradoxically, this low and probabilistic fertilization success co-occurs with other notable characteristics of male quail suggestive of past sexual selection for increased success, including vigorous copulatory behavior, forced copulations, foamy secretion aiding in sperm competition, large testes and unusual sperm morphology.

No MeSH data available.


Related in: MedlinePlus

Experiment 1.Percentages of eggs laid by 20 females following a single insemination on days 2–4 of the laying sequence (day 0 = day of mating) that had sperm penetration holes in the perivitelline membrane (clear bars) or contained embryos after one week of incubation (gray bars). The fertilization failure percentages (100% minus the values shown by the bars) were 53% (day 2), 37% (day 3) and 37% (day 4) for sperm holes, and 56% (day 2), 40% (day 3) and 50% (day 4) for embryos. The fertilization outcomes were very similar for the two outcome measures.
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pone.0131786.g001: Experiment 1.Percentages of eggs laid by 20 females following a single insemination on days 2–4 of the laying sequence (day 0 = day of mating) that had sperm penetration holes in the perivitelline membrane (clear bars) or contained embryos after one week of incubation (gray bars). The fertilization failure percentages (100% minus the values shown by the bars) were 53% (day 2), 37% (day 3) and 37% (day 4) for sperm holes, and 56% (day 2), 40% (day 3) and 50% (day 4) for embryos. The fertilization outcomes were very similar for the two outcome measures.

Mentions: The number of sperm holes in each egg ranged from 0 to 70, with a mean of 15 holes for the 34 eggs that had at least one hole. The percentages of eggs that had either sperm holes in the perivitelline membrane or an embryo following incubation for the three egg collection days are shown in Fig 1 (S1 Dataset). The percentages of successes and failures for each of the two outcomes were very similar and did not differ statistically for any of the three days (all McNemar’s binomial p > 0.6).


Hit or Miss: Fertilization Outcomes of Natural Inseminations by Japanese Quail.

Adkins-Regan E - PLoS ONE (2015)

Experiment 1.Percentages of eggs laid by 20 females following a single insemination on days 2–4 of the laying sequence (day 0 = day of mating) that had sperm penetration holes in the perivitelline membrane (clear bars) or contained embryos after one week of incubation (gray bars). The fertilization failure percentages (100% minus the values shown by the bars) were 53% (day 2), 37% (day 3) and 37% (day 4) for sperm holes, and 56% (day 2), 40% (day 3) and 50% (day 4) for embryos. The fertilization outcomes were very similar for the two outcome measures.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4519265&req=5

pone.0131786.g001: Experiment 1.Percentages of eggs laid by 20 females following a single insemination on days 2–4 of the laying sequence (day 0 = day of mating) that had sperm penetration holes in the perivitelline membrane (clear bars) or contained embryos after one week of incubation (gray bars). The fertilization failure percentages (100% minus the values shown by the bars) were 53% (day 2), 37% (day 3) and 37% (day 4) for sperm holes, and 56% (day 2), 40% (day 3) and 50% (day 4) for embryos. The fertilization outcomes were very similar for the two outcome measures.
Mentions: The number of sperm holes in each egg ranged from 0 to 70, with a mean of 15 holes for the 34 eggs that had at least one hole. The percentages of eggs that had either sperm holes in the perivitelline membrane or an embryo following incubation for the three egg collection days are shown in Fig 1 (S1 Dataset). The percentages of successes and failures for each of the two outcomes were very similar and did not differ statistically for any of the three days (all McNemar’s binomial p > 0.6).

Bottom Line: Variation in fertilization success underlies sexual selection, yet mating does not guarantee fertilization.Both sexes gained similar numbers of fertilized eggs by mating with a second partner the next day, but males, unlike females in a previous study, did not gain by having two females to mate with at the same time.Even double inseminations often failed to fertilize any eggs, and multiple matings would be needed for an entire clutch to be fertilized with high certainty.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology and Department of Neurobiology and Behavior, Cornell University, Ithaca, New York, United States of America.

ABSTRACT
Variation in fertilization success underlies sexual selection, yet mating does not guarantee fertilization. The relationship between natural inseminations and fertilization success is essential for understanding sexual selection, yet that relationship and its underlying mechanisms are poorly understood in sperm-storing vertebrates such as birds. Here the relationship is analyzed in mating trials using Japanese quail (Coturnix japonica), which show striking variation in the fertilizing success of inseminations. Failures of males' inseminations to fertilize eggs were mainly due to failures prior to sperm-egg contact. Fertilization probabilities on any given day were unrelated to whether the female had laid an egg the previous day, arguing against stimulation of sperm release from sperm storage tubules by the events of the daily egg-laying cycle. Instead, an unfertilized egg laid between two fertilized eggs predicted a longer sperm storage interval. Both sexes gained similar numbers of fertilized eggs by mating with a second partner the next day, but males, unlike females in a previous study, did not gain by having two females to mate with at the same time. Instead, they were both behaviorally and sperm limited, whereas females gain by mating twice in quick succession. Even double inseminations often failed to fertilize any eggs, and multiple matings would be needed for an entire clutch to be fertilized with high certainty. Paradoxically, this low and probabilistic fertilization success co-occurs with other notable characteristics of male quail suggestive of past sexual selection for increased success, including vigorous copulatory behavior, forced copulations, foamy secretion aiding in sperm competition, large testes and unusual sperm morphology.

No MeSH data available.


Related in: MedlinePlus