Journal article

Publication year: 2002

Pages: 333-347

Journal: Malacologia

Volume number: 44

Issue number: 2

ISSN: 0076-2997

URL: https://www.biodiversitylibrary.org/item/47347#page/341/mode/1up

Publisher: Institute of Malacology

Abstract: 
Chinese Oncomelania h. hupensis from the flood plains of the Yangtze River have ribbed shells. However, populations living above the effects of annual floods usually are smoothshelled. Previous allozyme studies of smooth-shelled populations not affected by flooding, and ribbed-shelled populations affected by flooding from the Miao River, Hubei Province, showed that they all belong to O. h. hupensis (Davis et al., 1999a). As the allozyme data were of limited use for assessing Oncomelania-population genetics, we re-examined the above populations to answer the following questions using mitochondrial COI sequence data. Will DNA sequences provide higher resolution for the analysis of population structure than allozyme data? Are there significant genetic differences among ribbed- and smooth-shelled populations? Do they differ in their susceptibility to infection with Schistosoma japonicum? Sequences from 59 individuals revealed four groups of haplotypes. Smooth- and ribbed-shelled individuals clustered together in two of the groups. The greatest sequence divergence between a smooth-shelled and ribbed-shelled population was 0.020, indicating that all populations fall within the range of variation expected for O. h. hupensis. Overall, the highest genetic diversity was found among downstream ribbed-shelled populations. The analysis of molecular variance (AMOVA) showed the following distribution of total variance: 69% (P < 0.0001) within populations, 9% (P less than or equal to 0.0025) among populations within the ribbed- and smooth-shelled groups, and 22% (P less than or equal to 0.0569) between the ribbed- and smooth-shelled populations. Mismatch distributions indicated that downstream populations are aggregates of snails from different populations. Downstream populations also showed a higher infectivity rate and a higher susceptibility to infection with Schistosoma japonicum. This is probably due to the importation and mixture of snail and parasite strains in flooded areas increasing the probability that schistosomes encounter genetically suitable snails, and/or the possibility of multiple infections by different parasite strains. The low infection rate in upstream populations is probably due to their relative isolation where there is equilibrium with low frequencies of infection.

Harvard Citation style: Shi, C., Wilke, T., Davis, G., Xia, M. and Qiu, C. (2002) Population genetics, micro-phylogeography, ecology, and susceptibility to schistosome infection of Chinese Oncomelania hupensis hupensis (Gastropoda : Rissooidea : Pomatiopsidae) in the Miao River system, Malacologia, 44(2), pp. 333-347. https://www.biodiversitylibrary.org/item/47347#page/341/mode/1up

APA Citation style: Shi, C., Wilke, T., Davis, G., Xia, M., & Qiu, C. (2002). Population genetics, micro-phylogeography, ecology, and susceptibility to schistosome infection of Chinese Oncomelania hupensis hupensis (Gastropoda : Rissooidea : Pomatiopsidae) in the Miao River system. Malacologia. 44(2), 333-347. https://www.biodiversitylibrary.org/item/47347#page/341/mode/1up