The effect of geographic range and dichogamy on genetic variability and population genetic structure in Tricyrtis
 section Flavae
 (Liliaceae)

We examined the population genetic structure of the amphipod Gammarus fasciatus (Crustacea: Amphipoda) over two years from a total of 11 sites within the Great Lakes - St. Lawrence River system using allozyme electrophoresis. In 1995, we examined differences within the St. Lawrence River (Cornwall to Quebec City), and in 1996, we focused on larger scale, whole-system differences from Lake Superior to Lake Champlain. We found very low levels of genetic differentiation among sites (Wright's FST < 0.03). This was not unexpected for an active disperser in a relatively contiguous system. However, we also found low levels of genetic variability within sites (Hobs = 0.07- 0.15), a result that was not anticipated. We surveyed the available literature on gammarid and other amphipods and found that limited genetic variability is characteristic of continuously distributed taxa, contrary to the expectations of current conservation theory. This is potentially of concern, especially in light of recently reported declines of G. fasciatus at several locations within the St. Lawrence River and Great Lakes. Given the importance of species such as G. fasciatus in aquatic food webs, further work is clearly needed on the consequences of population genetic structure to species' responses to novel environmental changes (e.g., exotic species introductions).

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Population genetic structure and the effect of historical human activity on the genetic variability of Cryptomeria japonica core collection, in Japan

Tree Genetics & Genomes ◽

10.1007/s11295-014-0758-5 ◽

2014 ◽

Vol 10 (5) ◽

pp. 1257-1270 ◽

Cited By ~ 7

Author(s):

Kentaro Uchiyama ◽

Naoko Miyamoto ◽

Makoto Takahashi ◽

Atsushi Watanabe ◽

Yoshihiko Tsumura

Keyword(s):

Genetic Structure ◽

Genetic Variability ◽

Human Activity ◽

Population Genetic Structure ◽

Cryptomeria Japonica ◽

Population Genetic ◽

Core Collection

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Microsatellite variation and population genetic structure of a neotropical endangered Bryconinae species Brycon insignis Steindachner, 1877: implications for its conservation and sustainable management

Neotropical Ichthyology ◽

10.1590/s1679-62252009000300006 ◽

2009 ◽

Vol 7 (3) ◽

pp. 395-402 ◽

Cited By ~ 15

Author(s):

Cristianne Kayoko Matsumoto ◽

Alexandre Wagner Silva Hilsdorf

Keyword(s):

Genetic Structure ◽

Genetic Variability ◽

Population Genetic Structure ◽

Population Genetic ◽

Food Resource ◽

Southeastern Brazil ◽

Captive Population ◽

Wild Populations ◽

Isolated Populations ◽

Microsatellite Variation

Piabanha (Brycon insignis) is a freshwater fish species from the drainages in Southeastern Brazil. During the 1950s, it was an important economic and food resource for local populations, but dramatic and continuous environmental degradation seriously jeopardized the B. insignis populations in the region. Microsatellite markers were used to assess the genetic structure of wild populations of B. insignis and compare the genetic variability and integrity of the wild populations with a captive population. Samples of DNA from 208 specimens from geographically isolated populations were analyzed. Population genetic structure was investigated using F ST, R ST estimates as well as AMOVA. All five loci used in this study were polymorphic with observed heterozygosity ranging from 0.77 (± 0.15) to 0.88 (± 0.07) in the wild population and 0.90 (± 0.09) in the captive population and the allelic richness average were 7.56 (± 0.27) and 5.80 (± 1.02), respectively. Overall genetic differences were significantly partitioned among populations (F ST = 0.072, p = 0.034). Evidence of a genetic bottleneck was found in some of the wild populations, but especially in the captive population. The results showed that genetic variability still can be found in B. insignis populations which are currently structured possibly due to anthropic actions. The implications of these findings for the management and conservation of B. insignis populations are discussed.

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