RESUMO
Objective To investigate the distribution and identify the genetic genetics of invasive Pomacea species in Xihu District, Hangzhou City, so as to understand the spread tendency of Pomacea species. Methods The specimens of Pomacea species were collected from five sites in water systems (lakes, rivers and wetlands) and its costal lands in Xihu District, Hangzhou City in 2017 for morphological identification. Total DNA was isolated from the foot tissues of adult snails for amplification of the COI gene, and haplotype diversity and nucleic acid diversity analyses were performed. In addition, a phylogenetic tree was created based on the haplotype captured from GenBank and those from this study to investigate the phylogenetic relationships. Results Pomacea specimens, which were preliminarily characterized as Pomacea, were found in ponds, rivers and wetlands in Xihu District of Hangzhou City. A total of 16 sequences were captured from the DNA samples of Pomacea specimens, which belonged to 3 haplotypes, including Hap1, Hap2 and Hap3. A high frequency was seen in Hap1 and Hap3, and a low frequency was found in Hap2. The Pomacea specimens collected from the 5 sites in Xihu Districts included P. canaliculata and P. maculate. The Pomacea specimens with a Hap1 had a close genetic relationship with the P. canaliculata from Argentina, Guangdong Province and Hong Kong Special Administrative Region of China, and the Pomacea specimens with a Hap2 had a close genetic relationship with the P. canaliculata from Argentina, Japan and Guangzhou City of Guangdong Province, China, while the Pomacea specimens with a Hap2 had a close genetic relationship with the P. maculate from Argentina and Brazil. Conclusions P. canaliculata and P. maculata are present in Xihu District of Hangzhou City. P. maculata may spread to Xihu District through multiple introductions or water flow.
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Objective To investigate the expression of some genes in Pomacea canaliculata infected with Angiostrongylus cantonensis, so as to provide insight into the preliminary understanding of the interactions between Angiostrongylus cantonensis and its intermediate host Pomacea canaliculata. Methods P. canaliculata was fed with rat faces containing the first-stage larvae of A. cantonensis. Three to five P. canaliculata was sampled 1, 10 days and 20 days after feeding, and the hemolymph, hepatopancreas, kidney, intestinal tract, head-foot and gill tissues were collected, while uninfected P. canaliculata served as controls. Total RNA was extracted from various tissues of P. canaliculata at different time points post-infection, and transcribed reversely into cDNA. Based on previous transcriptome sequencing results, 10 genes associated with immune defense, signal transduction, cell growth and metabolism, stress response were selected, and the gene expression was determined in the hemolymph tissues of P. canaliculata 1, 10 days and 20 days post-infection with A. cantonensis using real-time fluorescent quantitative PCR assay, and the α-tubulin gene expression was quantified in the hepatopancreas, kidney, head-foot, intestinal tract and gill tissues of P. canaliculata infected with A. cantonensis. Results Higher CELA1 gene expression was detected in the infection group than in the control group 1 (t = 12.32, P < 0.05), 10 days (t = 23.51, P < 0.05) and 20 days post-infection (t = 34.92, P < 0.05), and the CELA1 expression increased with the time of infection. The GST gene expression was (7.26 ± 1.80) times higher in the infection group than in the control group 1 day post-infection, and was significantly lower in the infection group than in the control group 10 days (t = 23.89, P < 0.05) and 20 days post-infection (t = 19.83, P < 0.05). Higher ferritin gene expression was found in the infection group than in the control group 10 days post-infection (t = 32.76, P < 0.05), and higher CRT gene expression was seen in the infection group than in the control group 1 (t = 7.23, P < 0.05), 10 days (t = 5.78, P < 0.05) and 20 days post-infection (t = 6.32, P < 0.05). In addition, the greatest α-tubulin gene expression was observed in the the hepatopancreatic tissues of P. canaliculata (F = 17.58, P < 0.05), and the α-tubulin gene expression altered in various tissues of P. canaliculata post-infection with A. cantonensis, with the most remarkable reduction of α - tubulin gene expression seen in the hepatopancreatic tissues (P < 0.05). Conclusions Following A. cantonensis infection in P. canaliculata, the expression of multiple genes is altered, and the expression of α-tubulin gene is inhibited in multiple tissues. The findings provide a basis for the further elucidation of the interactions between P. canaliculata and A. cantonensis.
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Objective To study the seasonal dynamics of Culex pipiens pallens and the distribution of knockdown resistance (kdr) gene related sodium channel gene polymorphism in Zichuan District, Zibo City, Shandong Province. Methods Cx. pipiens pallens mosquitoes were collected in Zichuan District during the peak period of mosquito vector activity from 2017 to 2018. The DNA from Cx. pipiens pallens was extracted, and the genotypes and frequencies of kdr allele mutation were detected by polymerase chain reaction. Results Totally 830 mosquitoes belonging to six species, including Cx. pipiens pallens, Armigeres subalbatus, Aedes albopictus, Ae. vexans, Anopheles sinensis, and Cx. tritaeniorhchus were collected in this study. The number of Cx. pipiens pallens accounted for 83.13% in total, with the density of 12.32 per lamp per night. The annual density monitoring curve of Cx. pipiens pallens showed a bimodal trend, and the peaks were observed in June and September respectively. In this study, five kdr alleles were detected at the 1 014 locus of kdr gene, with TTA (75.71%), TTT (10.00%), CTA (5.71%), TCA (4.29%), and TTC (4.29%). Two nonsynonymous nucleotide mutations were detected at site 1 014 of kdr gene, namely leucine (L1014) mutated to phenylalanine (L1014F) and serine (L1014S). The kdr gene mutation frequency (%) of Cx. pipiens pallens in Luochun Town and Taihe Town was 10.53% and 40.63%, respectively, and the difference was statistically significant ( χ2 = 8.559, P = 0.003). Conclusions Cx. pipiens pallens is the dominant mosquito species in Zichuan District. In addition, two novel mutations, CTA and TTC, are identified in the voltage-dependent sodium channel gene of Cx. pipiens pallens. The kdr genotype of Cx. pipiens pallens in Zichuan area was polymorphic.
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Objective To study the seasonal dynamics of Culex pipiens pallens and the distribution of knockdown resistance (kdr) gene related sodium channel gene polymorphism in Zichuan District, Zibo City, Shandong Province. Methods Cx. pipiens pallens mosquitoes were collected in Zichuan District during the peak period of mosquito vector activity from 2017 to 2018. The DNA from Cx. pipiens pallens was extracted, and the genotypes and frequencies of kdr allele mutation were detected by polymerase chain reaction. Results Totally 830 mosquitoes belonging to six species, including Cx. pipiens pallens, Armigeres subalbatus, Aedes albopictus, Ae. vexans, Anopheles sinensis, and Cx. tritaeniorhchus were collected in this study. The number of Cx. pipiens pallens accounted for 83.13% in total, with the density of 12.32 per lamp per night. The annual density monitoring curve of Cx. pipiens pallens showed a bimodal trend, and the peaks were observed in June and September respectively. In this study, five kdr alleles were detected at the 1 014 locus of kdr gene, with TTA (75.71%), TTT (10.00%), CTA (5.71%), TCA (4.29%), and TTC (4.29%). Two nonsynonymous nucleotide mutations were detected at site 1 014 of kdr gene, namely leucine (L1014) mutated to phenylalanine (L1014F) and serine (L1014S). The kdr gene mutation frequency (%) of Cx. pipiens pallens in Luochun Town and Taihe Town was 10.53% and 40.63%, respectively, and the difference was statistically significant ( χ2 = 8.559, P = 0.003). Conclusions Cx. pipiens pallens is the dominant mosquito species in Zichuan District. In addition, two novel mutations, CTA and TTC, are identified in the voltage-dependent sodium channel gene of Cx. pipiens pallens. The kdr genotype of Cx. pipiens pallens in Zichuan area was polymorphic.
RESUMO
Objective To investigate the expression of some genes in Pomacea canaliculata infected with Angiostrongylus cantonensis, so as to provide insight into the preliminary understanding of the interactions between Angiostrongylus cantonensis and its intermediate host Pomacea canaliculata. Methods P. canaliculata was fed with rat faces containing the first-stage larvae of A. cantonensis. Three to five P. canaliculata was sampled 1, 10 days and 20 days after feeding, and the hemolymph, hepatopancreas, kidney, intestinal tract, head-foot and gill tissues were collected, while uninfected P. canaliculata served as controls. Total RNA was extracted from various tissues of P. canaliculata at different time points post-infection, and transcribed reversely into cDNA. Based on previous transcriptome sequencing results, 10 genes associated with immune defense, signal transduction, cell growth and metabolism, stress response were selected, and the gene expression was determined in the hemolymph tissues of P. canaliculata 1, 10 days and 20 days post-infection with A. cantonensis using real-time fluorescent quantitative PCR assay, and the α-tubulin gene expression was quantified in the hepatopancreas, kidney, head-foot, intestinal tract and gill tissues of P. canaliculata infected with A. cantonensis. Results Higher CELA1 gene expression was detected in the infection group than in the control group 1 (t = 12.32, P < 0.05), 10 days (t = 23.51, P < 0.05) and 20 days post-infection (t = 34.92, P < 0.05), and the CELA1 expression increased with the time of infection. The GST gene expression was (7.26 ± 1.80) times higher in the infection group than in the control group 1 day post-infection, and was significantly lower in the infection group than in the control group 10 days (t = 23.89, P < 0.05) and 20 days post-infection (t = 19.83, P < 0.05). Higher ferritin gene expression was found in the infection group than in the control group 10 days post-infection (t = 32.76, P < 0.05), and higher CRT gene expression was seen in the infection group than in the control group 1 (t = 7.23, P < 0.05), 10 days (t = 5.78, P < 0.05) and 20 days post-infection (t = 6.32, P < 0.05). In addition, the greatest α-tubulin gene expression was observed in the the hepatopancreatic tissues of P. canaliculata (F = 17.58, P < 0.05), and the α-tubulin gene expression altered in various tissues of P. canaliculata post-infection with A. cantonensis, with the most remarkable reduction of α - tubulin gene expression seen in the hepatopancreatic tissues (P < 0.05). Conclusions Following A. cantonensis infection in P. canaliculata, the expression of multiple genes is altered, and the expression of α-tubulin gene is inhibited in multiple tissues. The findings provide a basis for the further elucidation of the interactions between P. canaliculata and A. cantonensis.