Data from: Rare sexual reproduction by females of “obligate parthenogenetic” lineages of Daphnia cf. pulex
Data files
Apr 17, 2025 version files 3.12 KB
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Raw_data_(Tables_1-3).zip
963 B
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README.md
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Abstract
Rare sexual reproduction in otherwise asexual lineages is predicted to strongly alleviate long-term costs of asexuality while avoiding most of the cost of sex. Here, we test for rare sexual reproduction in females of obligate parthenogenetic (OP) lineages of Daphnia cf. pulex. We find that a small proportion, ~0.5%, of offspring contain paternal alleles when they are produced in the presence of males from a so-called cyclical parthenogenetic (CP) lineage of the species, thus demonstrating sexual reproduction. Rare sexual reproduction occurred in two independent tests, using females from two different OP lineages, suggesting that it may be a regular feature in OP lineages of the species. Even though it could not be established whether the sexual events involved fertilization of haploid or diploid eggs, these results disclose a reproductive trait entirely new to Daphnia biology, aligning with recent results in other organisms. Indeed, the occurrence of rare or cryptic events of sexual reproduction may be a common feature in lineages previously characterized as obligately parthenogenetic, with significant implications for the evolution of obligate asexuality, its long-term costs, and its genomic consequences, including the evolution of polyploidy.
Dataset DOI: 10.5061/dryad.kd51c5bj8
Description of the data and file structure
- Table 1
To estimate the number of adult females present at the end of the experiment in each of the two crossing tests, three random samples were taken (with replacement) from each culture once its volume had been reduced to the total volume indicated. For each sample, the sample volume and the number of adult females contained in the sample was quantified. Those three random samples were later used to calculate the average and standard error (s.e.) of the number of adult females per ml of the total volume, as well as extrapolated to estimate the total number of females in each culture.
- Table 2
In order to estimate the numbers of diapause capsules present at the end of the experiment in each of the two crossing tests, three random samples of 1 ml were taken (with replacement) from each culture once all diapause capsules had been re-suspended in the “total volume” indicated. The number of diapause capsules contained in each sample was quantified. Those samples were used to calculate the average and standard error (s.e.) of the number of diapause capsules per ml of the re-suspension, and then extrapolated to estimate the total number of diapause capsules produced in each culture.
- Table 3
Number of diapause capsules opened in each of the two crossing tests and embryos used for the genotyping tests. Two places for embryos are available in each diapause capsule. Therefore, the number of diapause capsules containing two, one, or no embryos was also recorded. Additional diapause capsules were opened to obtain the 450 embryos for the genotyping tests in the crossing test DIS85xKAP65. Capsules with zero, one, or two embryos were assumed to occur at the same rate as in the first batch of 235 diapause capsules. The division of the number of embryos by the number of places gives the fill rate of diapause capsules, a variable that was later calculated in our study thanks to those data.