Incomplete lineage sorting and introgression are 2 major and nonexclusive causes of specieslevel non-monophyly.Distinguishing between these 2 processes is notoriously difficult because they can generate similar geneti...Incomplete lineage sorting and introgression are 2 major and nonexclusive causes of specieslevel non-monophyly.Distinguishing between these 2 processes is notoriously difficult because they can generate similar genetic signatures.Previous studies have suggested that 2 closely related duck species,the Chinese spot-billed duck Anas zonorhyncha and the mallard A.platyrhynchosvjere polyphyletically intermixed.Here,we utilized a wide geographical sampling,multilocus data and a coalescent-based model to revisit this system.Our study confirms the finding that Chinese spot-billed ducks and Mallards are not monophyletic.There was no apparent interspecific differentiation across loci except those at the mitochondrial DNA(mtDNA)control region and the Z chromosome(CHD1Z).Based on an isolation-with-migration model and the geographical distribution of lineages,we suggest that both introgression and incomplete lineage sorting might contribute to the observed non-monophyly of the 2 closely related duck species.The mtDNA introgression was asymmetric,with high gene flow from Chinese spot-billed ducks to Mallards and negligible gene flow in the opposite direction.Given that the 2 duck species are phenotypically distinctive but weakly genetically differentiated,future work based on genomescale data is necessary to uncover genomic regions that are involved in divergence,and this work may provide further insights into the evolutionary histories of the 2 species and other waterfowls.展开更多
Three experiments(Exp.1,n=144 broilers[Ross×Ross];Exp.2,n=118 mallard ducklings[Anas platyrhynchos];and Exp.3,n=75 mature mallard ducks)were conducted to determine the effects of 3 levels of unmilled hybrid rice ...Three experiments(Exp.1,n=144 broilers[Ross×Ross];Exp.2,n=118 mallard ducklings[Anas platyrhynchos];and Exp.3,n=75 mature mallard ducks)were conducted to determine the effects of 3 levels of unmilled hybrid rice on growth performance and organ and gastrointestinal tract develop-ment.The dietary treatments were 1)corn-soybean meal(basal),2)basal+5%hybrid rice,and 3)basal+10%hybrid rice for Exp.1 to 3,respectively.One bird from each pen in Exp.1(n=24)and all the birds in Exp.2(n=118)and Exp.3(n=75)were randomly selected and euthanized to determine linear measurements and organ and gastrointestinal tract weight.In Exp.1 and 2,birds fed 10%rice experi-enced slower growth(P<0.05)than birds fed the basal diet.In Exp.3,the addition of rice did not affect growth performance.Rice addition did not affect organ length or weight(P>0.05)in Exp.1.However,birds fed 5%rice had significantly increased(P<0.05)pancreas,ileum,and jejunum weights in Exp.2,and 10%rice significantly increased(P<0.05)liver weight in Exp.3.The addition of 10%unmilled rice to broiler and duck diets may reduce growth performance.展开更多
As a forerunner of feminist authors of the 20 th century, Kate Chopin explores the social role, the emotional role of women and their wants and needs in her works. Her feminism themes can not be separated from her own...As a forerunner of feminist authors of the 20 th century, Kate Chopin explores the social role, the emotional role of women and their wants and needs in her works. Her feminism themes can not be separated from her own life experiences. So based on her owning sufferings, she creates the heroin Mrs. Mallard in "The Story of an Hour". She wants to spread her feminism to the world from Mrs. Mallard. But both the author and her character reflect the oppressed feminism. Through the comparison between the author and Mrs. Mallard, the article discloses feminism can not be accepted in a patriarchal society. But both the author and Mrs. Mallard show the awakening of female consciousness.展开更多
基金the National Natural Science Foundation of China(No.31401969,31772480)the Natural Science Foundation of Jiangxi Province(No.20161BAB214158).
文摘Incomplete lineage sorting and introgression are 2 major and nonexclusive causes of specieslevel non-monophyly.Distinguishing between these 2 processes is notoriously difficult because they can generate similar genetic signatures.Previous studies have suggested that 2 closely related duck species,the Chinese spot-billed duck Anas zonorhyncha and the mallard A.platyrhynchosvjere polyphyletically intermixed.Here,we utilized a wide geographical sampling,multilocus data and a coalescent-based model to revisit this system.Our study confirms the finding that Chinese spot-billed ducks and Mallards are not monophyletic.There was no apparent interspecific differentiation across loci except those at the mitochondrial DNA(mtDNA)control region and the Z chromosome(CHD1Z).Based on an isolation-with-migration model and the geographical distribution of lineages,we suggest that both introgression and incomplete lineage sorting might contribute to the observed non-monophyly of the 2 closely related duck species.The mtDNA introgression was asymmetric,with high gene flow from Chinese spot-billed ducks to Mallards and negligible gene flow in the opposite direction.Given that the 2 duck species are phenotypically distinctive but weakly genetically differentiated,future work based on genomescale data is necessary to uncover genomic regions that are involved in divergence,and this work may provide further insights into the evolutionary histories of the 2 species and other waterfowls.
文摘Three experiments(Exp.1,n=144 broilers[Ross×Ross];Exp.2,n=118 mallard ducklings[Anas platyrhynchos];and Exp.3,n=75 mature mallard ducks)were conducted to determine the effects of 3 levels of unmilled hybrid rice on growth performance and organ and gastrointestinal tract develop-ment.The dietary treatments were 1)corn-soybean meal(basal),2)basal+5%hybrid rice,and 3)basal+10%hybrid rice for Exp.1 to 3,respectively.One bird from each pen in Exp.1(n=24)and all the birds in Exp.2(n=118)and Exp.3(n=75)were randomly selected and euthanized to determine linear measurements and organ and gastrointestinal tract weight.In Exp.1 and 2,birds fed 10%rice experi-enced slower growth(P<0.05)than birds fed the basal diet.In Exp.3,the addition of rice did not affect growth performance.Rice addition did not affect organ length or weight(P>0.05)in Exp.1.However,birds fed 5%rice had significantly increased(P<0.05)pancreas,ileum,and jejunum weights in Exp.2,and 10%rice significantly increased(P<0.05)liver weight in Exp.3.The addition of 10%unmilled rice to broiler and duck diets may reduce growth performance.
文摘As a forerunner of feminist authors of the 20 th century, Kate Chopin explores the social role, the emotional role of women and their wants and needs in her works. Her feminism themes can not be separated from her own life experiences. So based on her owning sufferings, she creates the heroin Mrs. Mallard in "The Story of an Hour". She wants to spread her feminism to the world from Mrs. Mallard. But both the author and her character reflect the oppressed feminism. Through the comparison between the author and Mrs. Mallard, the article discloses feminism can not be accepted in a patriarchal society. But both the author and Mrs. Mallard show the awakening of female consciousness.
