Genetic variation and patterns of genetic differentiation of the rice stem borer, Chilo suppressalis （Lepidoptera： Pyralidae）, from the South China were analyzed using 6 microsatellite markers and two partial mtDNA...Genetic variation and patterns of genetic differentiation of the rice stem borer, Chilo suppressalis （Lepidoptera： Pyralidae）, from the South China were analyzed using 6 microsatellite markers and two partial mtDNA （cox1 and cox2） regions. All of the 6 microsatellite loci were polymorphic in the studied seven populations. The allelic richness per population ranged between 5.67 and 14.00, and average H E and H O values were 0.6246-0.8329 and 0.2634-0.6061, respectively. As the mitochondrial genome is a single genetic locus, we only present results for the concatenated data set （cox1 plus cox2 gene sequences, 513 bp）. The concatenated data showed high level of genetic diversity and there are 23 variable polymorphic sites among the 513 sites in concatenated data. Nearly all of （20 of 21） pairwise F ST comparisons among populations showed genetic differentiation with moderate to high pairwise F ST values based on microsatellite markers. However, for the mtDNA data, most of the seven populations did not show significant differentiation with other populations. The differences of population differentiation obtained with the two different genetic markers could be mainly attributed to the different mutation rates of microsatellite and mtDNA. There was not genetic structure existed in these studied populations based on microsatellite loci and mtDNA data. The analysis based on network, mismatch distribution, Tajima＇s D and F S indicated that the studied populations were from the recent same ancestor or the same refuge and followed by a sudden demographic expansion condition.展开更多
Tetragonisca angustula is one of the most widespread stingless bees in the Neotropics. This species swarms frequently and is extremely successful in urban envi- ronments. In addition, it is one of the most popular sti...Tetragonisca angustula is one of the most widespread stingless bees in the Neotropics. This species swarms frequently and is extremely successful in urban envi- ronments. In addition, it is one of the most popular stingless bee species for beekeeping in Latin America, so nest transportation and trading is common. Nest transportation can change the genetic structure of the host population, reducing inbreeding and increasing homogenization. Here, we evaluate the genetic structure of 17 geographic populations of T. angustula in southern Brazil to quantify the level of genetic differentiation between populations. Analyses were conducted on partially sequenced mitochondrial genes and 11 microsatellite loci of 1002 workers from 457 sites distributed on the mainland and on 3 islands. Our results show that T. angustula populations are highly differentiated as demon- strated by mitochondrial DNA （mtDNA） and microsatellite markers. Of 73 haplotypes, 67 were population-specific. MtDNA diversity was low in 9 populations but microsatellite diversity was moderate to high in all populations. Microsatellite data suggest 10 genetic clusters and low level of gene flow throughout the studied area. However, physical barri- ers, such as rivers and mountain ranges, or the presence or absence of forest appear to be unrelated to population clusters. Factors such as low dispersal, different ecological con- ditions, and isolation by distance are most likely shaping the population structure of this species. Thus far, nest transportation has not influenced the general population structure in the studied area. However, due to the genetic structure we found, we recommend that nest transportation should only occur within and between populations that are genetically similar.展开更多
基金supported by the Guangdong Provincial Public Laboratory on Wild Animal Conservation and Management,China(2008-003)the National 973 Program of China(2010CB951503)
文摘Genetic variation and patterns of genetic differentiation of the rice stem borer, Chilo suppressalis （Lepidoptera： Pyralidae）, from the South China were analyzed using 6 microsatellite markers and two partial mtDNA （cox1 and cox2） regions. All of the 6 microsatellite loci were polymorphic in the studied seven populations. The allelic richness per population ranged between 5.67 and 14.00, and average H E and H O values were 0.6246-0.8329 and 0.2634-0.6061, respectively. As the mitochondrial genome is a single genetic locus, we only present results for the concatenated data set （cox1 plus cox2 gene sequences, 513 bp）. The concatenated data showed high level of genetic diversity and there are 23 variable polymorphic sites among the 513 sites in concatenated data. Nearly all of （20 of 21） pairwise F ST comparisons among populations showed genetic differentiation with moderate to high pairwise F ST values based on microsatellite markers. However, for the mtDNA data, most of the seven populations did not show significant differentiation with other populations. The differences of population differentiation obtained with the two different genetic markers could be mainly attributed to the different mutation rates of microsatellite and mtDNA. There was not genetic structure existed in these studied populations based on microsatellite loci and mtDNA data. The analysis based on network, mismatch distribution, Tajima＇s D and F S indicated that the studied populations were from the recent same ancestor or the same refuge and followed by a sudden demographic expansion condition.
文摘Tetragonisca angustula is one of the most widespread stingless bees in the Neotropics. This species swarms frequently and is extremely successful in urban envi- ronments. In addition, it is one of the most popular stingless bee species for beekeeping in Latin America, so nest transportation and trading is common. Nest transportation can change the genetic structure of the host population, reducing inbreeding and increasing homogenization. Here, we evaluate the genetic structure of 17 geographic populations of T. angustula in southern Brazil to quantify the level of genetic differentiation between populations. Analyses were conducted on partially sequenced mitochondrial genes and 11 microsatellite loci of 1002 workers from 457 sites distributed on the mainland and on 3 islands. Our results show that T. angustula populations are highly differentiated as demon- strated by mitochondrial DNA （mtDNA） and microsatellite markers. Of 73 haplotypes, 67 were population-specific. MtDNA diversity was low in 9 populations but microsatellite diversity was moderate to high in all populations. Microsatellite data suggest 10 genetic clusters and low level of gene flow throughout the studied area. However, physical barri- ers, such as rivers and mountain ranges, or the presence or absence of forest appear to be unrelated to population clusters. Factors such as low dispersal, different ecological con- ditions, and isolation by distance are most likely shaping the population structure of this species. Thus far, nest transportation has not influenced the general population structure in the studied area. However, due to the genetic structure we found, we recommend that nest transportation should only occur within and between populations that are genetically similar.
