Trypanosoma brucei gambiense: Study of population genetic structure of Central African stocks using amplified fragment length polymorphism (AFLP)

AbstractOmmatissus lybicus de Bergevin (Hemiptera: Tropiduchidae) is a key pest of date palm (Phoenix dactylifera Linnaeus; Arecaceae) with worldwide distribution and various management strategies. To study genetic diversity of date palm hopper, a series of experiments was conducted on genetic structure and genetic diversity of 15 geographic populations of O. lybicus (Abu Musa, Bam, Bushehr, Behbahan, Tezerj, Fin, Jiroft, Shahdad, Jahrom, Ghire Karzin, Ghasre Shirin, Iran; Pakistan; Oman; Egypt; and Tunisia) by amplified fragment length polymorphism, cytochrome c oxidase subunit I (COI), and 28S rRNA markers. Analysis of molecular variance analysis of amplified fragment length polymorphism data and COI sequences revealed a significant variation among O. lybicus populations (94.12% and 65.08% similarities for amplified fragment length polymorphism and COI, respectively). The 28S rDNA sequences from different populations were identical. Phylogenetic network inferred from amplified fragment length polymorphism data and COI sequences grouped two geographically close populations (Tezerj and Bam) in the two distinct clades while far apart geographical populations bunched in the same or close clades. These two populations experience repeated exposure to heavy pesticide applications annually. In conclusion, study of the genetic structure revealed a considerable variation between O. lybicus populations under intensive chemical strategies.

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Amplified fragment length polymorphism and mitochondrial sequence data detect genetic differentiation and relationships in endangered southwestern U.S.A. ambersnails (Oxyloma spp.)

Canadian Journal of Zoology ◽

10.1139/z00-119 ◽

2000 ◽

Vol 78 (10) ◽

pp. 1845-1854 ◽

Cited By ~ 5

Author(s):

Mark P Miller ◽

Larry E Stevens ◽

Joseph D Busch ◽

Jeff A Sorensen ◽

Paul Keim

Keyword(s):

Length Polymorphism ◽

Fragment Length ◽

Population Genetic ◽

Fragment Length Polymorphism ◽

Sequence Data ◽

Amplified Fragment Length Polymorphism ◽

Group Method ◽

Exact Test ◽

Additional Information ◽

Pair Group

The Kanab ambersnail (Oxyloma haydeni kanabensis) is a federally endangered mollusc currently known to reside in two locations in the southwestern U.S.A. To determine the extent of within- and between-population genetic variation of this taxon, the amplified fragment length polymorphism (AFLP) technique was used to generate 110 genetic markers among individuals sampled from the two Kanab ambersnail populations and from the only two known southwestern populations of the Niobrara ambersnail (Oxyloma haydeni haydeni) in Utah and northern Arizona. Additional information was obtained from sequence data of cytochrome b and cytochrome oxidase I gene fragments. Results suggest high levels of differentiation among populations, as evidenced through the application of UPGMA (unweighted pair-group method with arthimetic averaging) clustering, F statistics, and Fisher's exact test. Various levels of within-population genetic diversity were observed among populations. Expected heterozygosities ranged from 0.239 to 0.086 under a model assuming Hardy-Weinberg genotypic proportions and ranged from 0.205 to 0.061 under an obligate-selfing completely homozygous model. Results from cluster analyses showed that one Kanab ambersnail population and one Niobrara ambersnail population were more similar than the two Kanab ambersnail populations studied (supported by >80% of bootstrap replicates). These findings were further supported through the phylogenetic analysis of both mito chondrial gene fragments. The data suggest that taxonomic designations need revision, an act that will likely affect the protected status of some of the populations.

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