scholarly journals Evaluation of Allozyme and Microsatellite Variation in Texas and Florida Mottled Ducks

The Condor ◽  
2005 ◽  
Vol 107 (1) ◽  
pp. 155-161 ◽  
Author(s):  
Christen L. Williams ◽  
Alan M. Fedynich ◽  
Dan B. Pence ◽  
Olin E. Rhodes

Abstract Genetic variation was evaluated in Florida Mottled Ducks (Anas fulvigula), and Mottled Ducks from the larger Texas population using 22 allozyme and 5 microsatellite loci. Both marker types revealed differences in allele frequencies between populations and each population possessed rare and unique alleles. Overall allelic distributions were significantly different between the two populations, primarily due to significant differences at three allozyme and four microsatellite loci. Significant genetic differentiation was revealed between populations with both marker types, however, over all loci, only 5–6% of the variation detected was partitioned between populations. The Florida population possessed lower levels of allozyme heterozygosity and allelic diversity than the Texas population. In contrast, microsatellite heterozygosities and allelic diversity were similar between populations. These data indicate that there is limited gene flow between populations, suggesting that populations should continue to be managed separately. Evaluación de la Variación en Aloenzimas y Microsatélites en Anas fulvigula en Texas y Florida Resumen. Se evaluó la variación genética en el pato Anas fulvigula en Florida y en una población más grande de Texas, utilizando 22 aloenzimas y 5 loci microsatelitales. Ambos marcadores revelaron que existen diferencias entre las poblaciones en sus frecuencias alélicas, y cada población presentó alelos raros y únicos. La distribución general de alelos fue significativamente diferente entre las dos poblaciones, debido principalmente a diferencias significativas en tres aloenzimas y cuatro loci microsatelitales. Se encontró una diferenciación genética significativa entre las poblaciones considerando ambos marcadores, sin embargo, considerando los loci en conjunto, sólo el 5–6% de la variación detectada estuvo repartida entre las poblaciones. La población de Florida presentó niveles menores de heterocigocidad y diversidad alélica en las aloenzimas que la población de Texas. En contraste, la heterocigocidad y la diversidad alélica de los microsatélites fueron similares entre las poblaciones. Estos datos indican que el flujo génico entre las poblaciones es limitado, sugiriendo que deben seguir siendo manejadas de modo separado.

1997 ◽  
Vol 54 (7) ◽  
pp. 1548-1556 ◽  
Author(s):  
J C Patton ◽  
B J Gallaway ◽  
R G Fechhelm ◽  
M A Cronin

There has been concern that a causeway leading to oil production facilities in the Alaskan Beaufort Sea could affect the extent of emigration from, and immigration into, a population of broad whitefish (Coregonus nasus) in the Sagavanirktok River. To assess this, we analyzed the genetic relationships of the broad whitefish populations in the Sagavanirktok River, and the nearest adjacent population, in the Colville River. Three microsatellite loci from the nuclear genome, and the NADH-1 gene of mitochondrial DNA (mtDNA), were analyzed. Diploid genotypes were determined with PCR amplification of the microsatellite loci, and mtDNA genotypes were identified with PCR amplification followed by sequencing of 798 nucleotides. Several alleles were identified at each locus and both populations had high levels of genetic variation. There is significant differentiation of the Sagavanirktok River and Colville River broad whitefish stocks for the three microsatellite loci (FST = 0.031) but not mtDNA (FST < 0.001). Possible explanations for the lower level of differentiation of mtDNA than microsatellites include female-mediated gene flow between populations, skewed sex ratios, natural selection, or mutation. The results indicate that there is limited gene flow between the Colville and Sagavanirktok rivers, which represent semi-isolated spawning populations.


The Condor ◽  
2007 ◽  
Vol 109 (4) ◽  
pp. 954-962
Author(s):  
Robert C. Fleischer ◽  
Beth Slikas ◽  
Jon Beadell ◽  
Colm Atkins ◽  
Carl E. McINTOSH ◽  
...  

Abstract The Millerbird (Acrocephalus familiaris) is an endemic Northwestern Hawaiian Islands reed warbler that existed until about 1923 on Laysan Island (A. f. familiaris) and currently occurs in a small population on Nihoa Island (A. f. kingi). The two populations are described as separate subspecies or species on the basis of size and plumage differences. We assessed genetic variation in blood samples from 15 individuals in the modern Nihoa population using approximately 3000 base pairs (bp) of mitochondrial DNA (mtDNA) sequence and 14 microsatellite loci. We also obtained up to 1028 bp of mtDNA sequence from the fragmented DNA of museum specimens of three birds collected on Nihoa in 1923 and five birds collected on Laysan in 1902 and 1911 (ancient samples). Genetic variation in both marker types was extremely low in the modern Nihoa population (nucleotide diversity [π]  =  0.00005 for mtDNA sequences; observed heterozygosity was 7.2% for the microsatellite loci). In contrast, we found three mtDNA haplotypes among the five Laysan individuals (π  =  0.0023), indicating substantially greater genetic variation. The Nihoa and Laysan taxa differed by 1.7% uncorrected mtDNA sequence divergence, a magnitude that would support designation at the subspecies, and perhaps species, level relative to other closely related Acrocephalus species pairs. However, in light of strong ecological similarity between the two taxa, and a need to have additional populations to prevent extinction from stochastic effects and catastrophes, we believe these genetic differences should not deter a potential translocation of individuals from Nihoa to Laysan.


HortScience ◽  
2010 ◽  
Vol 45 (2) ◽  
pp. 314-315 ◽  
Author(s):  
Hai-fei Yan ◽  
Xue-jun Ge ◽  
Chi-ming Hu ◽  
Gang Hao

Nine microsatellite loci were isolated from Primula obconica using the FIASCO protocol. We used 30 individuals from three populations for the assessment of microsatellite variation. Seven loci were detected with microsatellite polymorphism. The number of alleles per locus ranged from three to seven. The average observed heterozygosity and expected heterozygosity ranged from 0.167 to 0.6 and from 0.409 to 0.653, respectively. These microsatellite markers will be useful to assess the genetic variation and genetic structure of P. obconica.


2008 ◽  
Vol 57 (1-6) ◽  
pp. 193-202 ◽  
Author(s):  
I. J. Chybicki ◽  
A. Dzialuk ◽  
M. Trojankiewicz ◽  
M. Slawski ◽  
J. Burczyk

AbstractWhen considering neutral nuclear markers, genetic differentiation of Scots pine (Pinus sylvestris L.) populations is known to be low. The homogeneity arises particularly as an effect of common ancestry in a recent evolutionary history as well as an extensive gene flow, especially through pollen. However, within populations several other forces may shape the spatial distribution of genetic variation, including establishment history, environmental and silvicultural selection. These local forces are known to produce non-random spatial patterns of genetic variation, however little is known on fine-scale spatial genetic structure of Scots pine. In this study, two stands of this species with different establishment histories, selected within one larger population located in northern Poland were genotyped and analysed for genetic variation and within-stand spatial genetic structure. Results revealed no differences in genetic variation, although stands are separated about 60 km, suggesting that the two populations share a common genetic pool. The spatial genetic structure in both stands was found to be slightly different and was attributed to differences in the mode of populations’ establishments. Finally, results confirmed that gene flow in Scots pine is extensive, causing genetic homogeneity within a single population.


2021 ◽  
Vol 19 (2) ◽  
pp. 279-288
Author(s):  
Dang Phan Hien ◽  
Nguyen Minh Duc ◽  
Nguyen Phan Lan Hong ◽  
Bui Thi Tuyet Xuan ◽  
Vu Dinh Duy ◽  
...  

Anisoptera costata Korth, an endangered species is distributed in lowland tropical forests of southern Vietnam. Habitat loss and over-exploitation are the major reasons for threatening this species. Eight polymorphic microsatellite markers were used to analyze 64 adult trees from three A. costata populations in lowland tropical forests of Tan Phu, Dinh Quan district, Dong Nai Province in Southeast Vietnam to detect the effects of deforestation on gene flow and the differentiation among populations in lowland tropical forests. The results showed that all A. costata populations have the moderate levels of the genetic diversity within populations with mean values of observed and expected heterozygosities, 0.242 and 0.269, respectively, moderate genetic differentiation among A. costata populations (0.179), and indicating limited gene flow (Nm = 1.15). Analysis of molecular variance indicated high genetic variation within populations (64.68%) and indicating moderate genetic structure in A. costata in Tan Phu. Bayesian analysis detected two genetic lineages, cluster 1 including one population of Mieu Co Nam and cluster 2 including two populations, Thac Mai and Bau Nuoc. These results contribute understanding genetic diversity of A. costata in lowland forests of Southeastern Vietnam and will provide guidelines for conservation, management and resoration of the species.


2005 ◽  
Vol 53 (2) ◽  
pp. 141 ◽  
Author(s):  
Xie Jianguang ◽  
Jian Shuguang ◽  
Liu Nian

Cycas debaoensis Y.C.Zhong et C.J.Chen is a rare and endangered cycad species that is endemic to South China. It has divided pinnae. Genetic variation in the species was investigated by using an intersimple sequence repeat (ISSR) marker. The species exhibits a moderate level of genetic diversity (at population level P = 34.7%, H = 0.141, I = 0.204; at species level P = 57.4%, H = 0.215, I = 0.315) and a high level of genetic differentiation among populations (Gst = 0.342). Thus, the indirect estimate of gene flow on the basis of Gst was low (Nm = 0.481). The narrow colonisation area and island pattern of distribution, combined with limited gene flow among populations and genetic drift, may play an important role in shaping the genetic structure of C. debaoensis. On the basis of these findings, strategies are suggested for the conservation and management of the species.


2016 ◽  
Vol 37 (4) ◽  
pp. 405-415 ◽  
Author(s):  
Agnieszka Konowalik ◽  
Anna Najbar ◽  
Wiesław Babik ◽  
Sebastian Steinfartz ◽  
Maria Ogielska

We analysed genetic variation within and differentiation between nineteen populations of the fire salamander Salamandra salamandra inhabiting the north-eastern margin of the species range in the Sudetes Mountains (south-western Poland). The results were compared with those obtained recently for the Polish part of the Carpathians. Variation of 10 nuclear microsatellite loci was analysed in 744 individuals to estimate genetic structure, gene flow, isolation and to test for a geographic gradient of genetic variation. Mitochondrial DNA control region (D-loop) of 252 specimens from all localities was used to identify the origin of populations currently inhabiting its north-eastern range. We found little genetic differentiation among populations in the Sudetes indicating substantial recent or ongoing gene flow. The exceptions were one isolated peripheral population located outside the continuous distribution range which displayed extremely reduced genetic variation probably due to a combination of long term isolation and low population size, and one population located at the eastern margin of the Polish Sudetes. Populations inhabiting the Sudetes and the Carpathians formed two separate clusters based on microsatellite loci. In accordance with available phylogeographic information, single mitochondrial haplotype (type IIb) fixed in all populations indicates their origin from a single refugium and may suggest colonization from the Balkan Peninsula. The analysis of geographic gradient in variation showed its decline in the westerly direction suggesting colonization of Poland from the east, however, alternative scenarios of postglacial colonization could not be rejected with the available data.


Author(s):  
Hussein M. Khaeim ◽  
Anthony Clark ◽  
Tom Pearson ◽  
Dr. David Van Sanford

Head scab is historically a devastating disease affecting not just all classes of wheat but also barley and other small grains around the world. Fusarium head blight (FHB), or head scab, is caused most often by Fusarium graminearum (Schwabe), (sexual stage – Gibberella zeae) although several Fusarium spp. can cause the disease. This study was conducted to determine the effect of mass selection for FHB resistance using an image-based optical sorter. lines were derived from the C0 and C2 of two populations to compare genetic variation within populations with and without sorter selection. Our overall hypothesis is that sorting grain results in improved Fusarium head blight resistance. Both of the used wheat derived line populations have genetic variation, and population 1 has more than population 17. They are significantly different from each other for fusarium damged kernel (FDK), deoxynivalenol (DON), and other FHB traits. Although both populations are suitable to be grown for bulks, population 1 seems better since it has more genetic variation as well as lower FDK and DON, and earlier heading date. Lines within each population were significantly different and some lines in each population had significantly lower FDK and DON after selection using an optical sorter. Some lines had significant reduction in both FDK and DON, and some others had either FDK or DON reduction. Lines of population 1 that had significant reduction, were more numerous than in population 17, and FDK and DON reduction were greater.


2011 ◽  
Vol 4 (2) ◽  
pp. 102-114 ◽  
Author(s):  
Evgenyi N. Panov ◽  
Larissa Yu. Zykova

Field studies were conducted in Central Negev within the breeding range of Laudakia stellio brachydactyla and in NE Israel (Qyriat Shemona) in the range of an unnamed form (tentatively “Near-East Rock Agama”), during March – May 1996. Additional data have been collected in Jerusalem at a distance of ca. 110 km from the first and about 170 km from the second study sites. A total of 63 individuals were caught and examined. The animals were marked and their subsequent movements were followed. Social and signal behavior of both forms were described and compared. Lizards from Negev and Qyriat Shemona differ from each other sharply in external morphology, habitat preference, population structure, and behavior. The differences obviously exceed the subspecies level. At the same time, the lizards from Jerusalem tend to be intermediate morphologically between those from both above-named localities, which permits admitting the existence of a limited gene flow between lizard populations of Negev and northern Israel. The lizards from NE Israel apparently do not belong to the nominate subspecies of L. stellio and should be regarded as one more subspecies within the species.


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