PMC:1044830 / 19024-21100 JSONTXT

{"target":"https://pubannotation.org/docs/sourcedb/PMC/sourceid/1044830","sourcedb":"PMC","sourceid":"1044830","source_url":"https://www.ncbi.nlm.nih.gov/pmc/1044830","text":"In order to evaluate the effect of the “opportunity for selection” for male haploid phase on ρ, we used selfing rate as an indirect variable estimating the degree of pollen competition. We assume that with high selfing rates, there is less genetic variation among competing pollen grains and, therefore, less scope for haploid selection. We defined Vm (the degree of male gamete competition in plants) using three values depending on the amount of selfing: 0 for dioecious, self-incompatible or largely outcrossing (less than 5% selfing reported) species; 1 for species exhibiting low selfing rates (less than 30% reported); and 2 for other species. We used these three broad categories to reflect the fact that selfing rate is often variable within species and that it is often measured indirectly and with low precision. We therefore expect a positive effect of the variable Vm on ρ if the opportunity for male gametic selection favours smaller ρ values, as predicted by the modifier model [18]. We tested this effect using the 57 species for which we were able to estimate Vm (Table 3). We used a linear model in R [29] assuming that all species are either independent or phylogenetically related. In the latter case, we used a generalized estimating equations linear model [26] with a plant phylogenetic tree to the family level using data from Davies et al. [30], and several calibration points, including the Picea/Pinus divergence approximately 140 million years ago [31], that are not included in the Davies et al. dataset. We found an effect in the right direction with or without correcting for the phylogeny (linear effect of ρ on Vm, p \u003c 0.0002 in both cases, Figure 2). The fact that selfing plants exhibit higher recombination rates than their outcrossing relatives has been mentioned previously in the literature [32,33]. However, in most cases, recombination was measured only in male meiosis. It would be valuable to reexamine this trend in the light of our results that recombination in male meiosis is typically greater than in female meiosis among selfers.","tracks":[{"project":"2_test","denotations":[{"id":"15736976-12618416-84798811","span":{"begin":993,"end":995},"obj":"12618416"},{"id":"15736976-12381290-84798812","span":{"begin":1278,"end":1280},"obj":"12381290"},{"id":"15736976-14766971-84798813","span":{"begin":1364,"end":1366},"obj":"14766971"},{"id":"15736976-10779538-84798814","span":{"begin":1475,"end":1477},"obj":"10779538"},{"id":"15736976-13635568-84798815","span":{"begin":1829,"end":1831},"obj":"13635568"},{"id":"15736976-13635567-84798816","span":{"begin":1832,"end":1834},"obj":"13635567"},{"id":"T49992","span":{"begin":993,"end":995},"obj":"12618416"},{"id":"T38773","span":{"begin":1278,"end":1280},"obj":"12381290"},{"id":"T24324","span":{"begin":1364,"end":1366},"obj":"14766971"},{"id":"T37497","span":{"begin":1475,"end":1477},"obj":"10779538"},{"id":"T86905","span":{"begin":1829,"end":1831},"obj":"13635568"},{"id":"T54730","span":{"begin":1832,"end":1834},"obj":"13635567"}],"attributes":[{"subj":"15736976-12618416-84798811","pred":"source","obj":"2_test"},{"subj":"15736976-12381290-84798812","pred":"source","obj":"2_test"},{"subj":"15736976-14766971-84798813","pred":"source","obj":"2_test"},{"subj":"15736976-10779538-84798814","pred":"source","obj":"2_test"},{"subj":"15736976-13635568-84798815","pred":"source","obj":"2_test"},{"subj":"15736976-13635567-84798816","pred":"source","obj":"2_test"},{"subj":"T49992","pred":"source","obj":"2_test"},{"subj":"T38773","pred":"source","obj":"2_test"},{"subj":"T24324","pred":"source","obj":"2_test"},{"subj":"T37497","pred":"source","obj":"2_test"},{"subj":"T86905","pred":"source","obj":"2_test"},{"subj":"T54730","pred":"source","obj":"2_test"}]}],"config":{"attribute types":[{"pred":"source","value type":"selection","values":[{"id":"2_test","color":"#ec93cb","default":true}]}]}}