Abstract: Objective　To analyze the potential spatial factors affecting the genetic differentiation of Oncomelania hupensis robertsoni in Yunnan Province. Methods　A total of 13 administrative villages were selected from schistosomiasis⁃endemic areas of Yunnan Province as O. hupensis snail sampling sites. At least 200 snails were collected in each site, and the spatial variable data of each site were recorded, including longitude, latitude and altitude. Thirty active and Schistosoma japonicum uninfected O. hupensis snails were selected from each sampling site by means of the crawling method and the cercarial shedding method. Genomic DNA was extracted from O. hupensis snails. Following PCR amplification, purification of PCR amplification products and sequencing, the gene sequences of O. hupensis snail samples were spliced and edited using the DNAstar software and the NCBI database to yield the complete mitochondrial sequences of O. hupensis snails at each sampling site, and the mitochondrial genetic distance matrix of O. hupensis robertsoni was calculated at each sampling site. The geographical coordinates of each sampling site were marked using the software ArcGIS 10.2, and the straight⁃line geographical distance between each sampling site was calculated. The altitude difference, longitude difference and latitude difference between each sampling site were calculated using the Excel software, and the correlation between the mitochondrial genetic distance matrix of O. hupensis robertsoni and each spatial variable matrix was examined by using the Mantel test at 13 sampling sites in Yunnan Province. Results　Among the 13 O. hupensis snail sampling sites in Yunnan Province, the largest mitochondrial genetic distance of O. hupensis robertsoni snail populations was seen between Anding Village, Nanjian Yi Autonomous County and Caizhuang Village, Midu County (26.244 2), and the largest geographical distance was seen between Dongyuan Village, Gucheng District and Cangling Village, Chuxiong County (272.64 km). The highest altitude difference was seen between Anding Village, Nanjian Yi Autonomous County and Dongyuan Village, Gucheng District (1 086.10 m), and the largest longitude difference was found between Qiandian Village, Eryuan County and Cangling Village, Chuxiong County (1.86°), while the largest latitude difference was measured between Leqiu Village, Nanjian Yi Autonomous County and Dongyuan Village, Gucheng District (1.81°). In addition, the mitochondrial genetic distance of O. hupensis robertsoni snail populations was positively correlated with altitude at 13 snail sampling sites in Yunnan Province (r = 0.542 8, P < 0.001), and showed no significant correlations with geographical distance (r = 0.093 4, P > 0.05), longitude (r = −0.199 5, P > 0.05) or latitude (r = 0.205 7, P > 0.05). Conclusion　Altitude may be a potential spatial factor affecting the genetic differentiation of O. hupensis robertsoni in Yunnan Province.

Key words: Oncomelania hupensis robertsoni, Genetic differentiation, Altitude, Longitude, Latitude, Yunnan Province

摘要： 目的　分析云南省钉螺滇川亚种遗传分化的潜在空间影响因素。方法　于云南省血吸虫病流行区选取13个行政村作为采样点进行钉螺采样，每点采集≥ 200只钉螺并记录采样点经纬度、海拔等空间变量数据。以爬行法结合逸蚴法于每个采样点筛选出30只活力良好的血吸虫感染阴性钉螺。提取钉螺线粒体基因，经PCR扩增、产物纯化及测序后，采用DNAstar软件和NCBI数据库对样本序列进行拼接、编辑，获得各采样点钉螺线粒体完整序列。计算各采样点钉螺滇川亚种线粒体遗传距离矩阵。采用ArcGIS 10.2软件标注各采样点地理坐标，计算各采样点间直线地理距离；采用Excel软件分别计算各采样点间海拔、经度差值和纬度差值。采用Mantel检验分析云南省13个采样点钉螺滇川亚种线粒体遗传距离矩阵与各空间变量矩阵的相关性。结果　云南省13个采样点中，南涧彝族自治县安定村和弥渡县蔡庄村的钉螺种群线粒体遗传距离最大，为26.244 2。古城区东元村与楚雄县苍岭村地理距离最远，为272.64 km。南涧彝族自治县安定村与古城区东元村海拔差值最大，为1 086.10 m。洱源县前甸村与楚雄县苍岭村经度差值最大，为1.86°；南涧彝族自治县乐秋村与古城区东元村纬度差值最大，为1.81°。云南省13个钉螺滇川亚种种群线粒体遗传距离与海拔呈正相关（r = 0.542 8，P < 0.001），与地理距离（r = 0.093 4）、经度（r = -0.199 5）和纬度（r = 0.205 7）相关性均无统计学意义（P均> 0.05）。结论　海拔可能是影响云南省钉螺滇川亚种遗传分化的潜在空间因素。

关键词: 湖北钉螺滇川亚种, 遗传分化, 海拔, 经度, 纬度, 云南省