The population genetic structure of the blacklegged tick Ixodes scapularis was analyzed using 853 individual ticks collected from 12 sites along the eastern seaboard of the United States. PCR-based DNA single strand ...The population genetic structure of the blacklegged tick Ixodes scapularis was analyzed using 853 individual ticks collected from 12 sites along the eastern seaboard of the United States. PCR-based DNA single strand conformation polymorphism(SSCP) was used for analysis of one haploid locus, the mitochondrial cytochrome b(Cyt b), and one diploid locus, the internal transcribed spacer 1(ITS1) of nuclear ribosomal RNA. Seven haplotypes in the Cyt b locus and 13 genotypes in the ITS1 locus were identified. Population differentiation and isolation by distance were found. Distribution of haplotype and genotype frequencies across geographic regions suggests that two distinct populations exist along the Eastern Coast of the US. However, genetic variation among individuals within regions was large. This degree of variation suggests frequent gene flow between regions. Moreover, overall genetic diversity among individuals was much higher in ticks from the southern population.展开更多
Invasive species are considered one of the greatest threats to native ecosystems, second only to habitat loss and frag- mentation. Despite this, the temporal dynamics of invasions are poorly understood, with most stud...Invasive species are considered one of the greatest threats to native ecosystems, second only to habitat loss and frag- mentation. Despite this, the temporal dynamics of invasions are poorly understood, with most studies focusing on a single time point, providing us with only a snapshot of the biology and genetics of the invader. We investigated the invasion of Lord Howe Island by the delicate skink Lampropholis delicata and assessed the introduction history and genetic structure of this species over a 5-year period. Using genetic data taken from 2007, and again in 2011/12, we examined changes in the population genetic struc- ture （whether new haplotypes had been introduced to the island, and shifts in haplotype frequencies） of the species on the island between these two time points. No new haplotypes were introduced to the island between 2007 and 2011/12; however, significant shifts in haplotype frequencies across the island were detected. We conclude that the delicate skink is expanding its range into the southern regions of the island and that the haplotype frequencies on Lord Howe Island are still in a state of highly dynamic flux. Our study highlights the importance of considering invasions as dynamic and studying them in such a way that enable us to better manage their impacts展开更多
文摘The population genetic structure of the blacklegged tick Ixodes scapularis was analyzed using 853 individual ticks collected from 12 sites along the eastern seaboard of the United States. PCR-based DNA single strand conformation polymorphism(SSCP) was used for analysis of one haploid locus, the mitochondrial cytochrome b(Cyt b), and one diploid locus, the internal transcribed spacer 1(ITS1) of nuclear ribosomal RNA. Seven haplotypes in the Cyt b locus and 13 genotypes in the ITS1 locus were identified. Population differentiation and isolation by distance were found. Distribution of haplotype and genotype frequencies across geographic regions suggests that two distinct populations exist along the Eastern Coast of the US. However, genetic variation among individuals within regions was large. This degree of variation suggests frequent gene flow between regions. Moreover, overall genetic diversity among individuals was much higher in ticks from the southern population.
文摘Invasive species are considered one of the greatest threats to native ecosystems, second only to habitat loss and frag- mentation. Despite this, the temporal dynamics of invasions are poorly understood, with most studies focusing on a single time point, providing us with only a snapshot of the biology and genetics of the invader. We investigated the invasion of Lord Howe Island by the delicate skink Lampropholis delicata and assessed the introduction history and genetic structure of this species over a 5-year period. Using genetic data taken from 2007, and again in 2011/12, we examined changes in the population genetic struc- ture （whether new haplotypes had been introduced to the island, and shifts in haplotype frequencies） of the species on the island between these two time points. No new haplotypes were introduced to the island between 2007 and 2011/12; however, significant shifts in haplotype frequencies across the island were detected. We conclude that the delicate skink is expanding its range into the southern regions of the island and that the haplotype frequencies on Lord Howe Island are still in a state of highly dynamic flux. Our study highlights the importance of considering invasions as dynamic and studying them in such a way that enable us to better manage their impacts
