Using AFLP markers to inform population management of the endemic Chatham Island toetoe, Austroderia turbaria (Poaceae).

2012 ◽  
Vol 18 (1) ◽  
pp. 33 ◽  
Author(s):  
Gary J Houliston ◽  
Murray I Dawson ◽  
Peter J De Lange ◽  
Peter B Heenan
Keyword(s):  
Management Practices ◽  
Flow Cytometric Analysis ◽  
Natural Populations ◽  
Source Material ◽  
Population Variation ◽  
Population Genetic Analysis ◽  
Flow Cytometric ◽  
Length Polymorphisms ◽  
Amplified Fragment Length Polymorphisms ◽  
Low Levels

Austroderia turbaria Connor is a threatened grass endemic to the Chatham Islands. Although formerly more widespread, remaining natural populations consist of highly fragmented remnants and/or individuals. Population genetic analysis of seed-raised progeny from six of the extant natural populations on Chatham and Pitt islands, using amplified fragment length polymorphisms (AFLPs) and microsatellite markers, shows that there are very low levels of variation (expected estimated heterozygosity He 0.023–0.030, no. of effective alleles Na 1.039–1.053), and no significant differentiation within or between populations on the two islands. Flow cytometric analysis of endosperm to embryo ratios suggests a sexual breeding system. This lack of population variation and no discernable differences between the two islands suggest that management practices such as the establishment of new populations can be carried out irrespective of the location of source material. One caveat to this is the possibility of Fusarium wilt occurring on the islands, in which case measures should be taken to best prevent spread across the range of the species.

Genetic diversity of arctic bramble (Rubus arcticus L. subsp. arcticus) as measured by amplified fragment length polymorphism

2003 ◽  
Vol 81 (8) ◽  
pp. 805-813 ◽  
Author(s):  
Hannele Lindqvist-Kreuze ◽  
Hilkka Koponen ◽  
Jari P.T Valkonen
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Fragment Length ◽  
Natural Habitat ◽  
Genotypic Variation ◽  
Natural Populations ◽  
Shannon Index ◽  
Length Polymorphisms ◽  
Amplified Fragment Length Polymorphisms ◽  
High Level

The levels of genotypic and genetic variation were estimated in six natural populations of arctic bramble (Rubus arcticus L. subsp. arcticus) in Finland. Using three primer combinations, a total of 117 amplified fragment length polymorphisms (AFLP) were found. The results were highly reproducible and allowed identification of 78 genets among the 122 plants of arctic bramble studied. Genotypic variation measured as Simpson index (D) was high in all populations, ranging from 0.72 to 0.94. Also, the level of genetic variation measured as Shannon index was relatively high in all populations, ranging from 0.19 to 0.32 (average 0.26). The high levels of genetic diversity indicate that sexual reproduction has played a significant role in these populations. The hierarchical analysis of molecular variance (AMOVA) partitioned 48% of the genetic variation among populations, suggesting a high level of population differentiation and a low level of interpopulation gene flow. Genetic diversity among ten currently grown cultivars of arctic bramble and hybrid arctic bramble (R. arcticus subsp. arcticus × R. arcticus subsp. stellatus) was large, and the subspecies were clearly distinguished from each other based on the AFLP marker data.Key words: AFLP, AMOVA, population, natural habitat, Rubus arcticus subsp. arcticus, Rubus arcticus subsp. stellatus.

scholarly journals Production of Fertile Unreduced Sperm by Hybrid Males of the Rutilus alburnoides Complex (Teleostei, Cyprinidae): An Alternative Route to Genome Tetraploidization in Unisexuals

Genetics ◽  
1999 ◽  
Vol 151 (1) ◽  
pp. 277-283
Author(s):  
M Judite Alves ◽  
M Manuela Coelho ◽  
M Isabel Próspero ◽  
M João Collares-Pereira
Keyword(s):  
Flow Cytometric Analysis ◽  
Natural Populations ◽  
Evolutionary Process ◽  
Reproductive Mode ◽  
Diploid Hybrid ◽  
Mendelian Segregation ◽  
Flow Cytometric ◽  
Hybrid Genome ◽  
Random Segregation ◽  
Diploid Sperm

Abstract The hybrid minnow Rutilus alburnoides comprises diploid and polyploid females and males. Previous studies revealed that diploid and triploid females exhibit altered oogenesis that does not involve random segregation and recombination of the genomes of the two ancestors, constituting unisexual lineages. In the present study, we investigated the reproductive mode of hybrid males from the Tejo basin, using experimental crosses and flow cytometric analysis of blood and sperm. The results suggest that diploid hybrids produced fertile unreduced sperm, transmitting their hybrid genome intact to offspring. Triploid hybrids also produced unreduced sperm, but it was not possible to obtain data concerning their fertility. Finally, tetraploid hybrids produced fertile diploid sperm, which exhibited Mendelian segregation. Tetraploid R. alburnoides may reestablish biparental reproduction, as individuals of both sexes with the appropriate constitution for normal meiosis (two haploid genomes from each parental species) are likely to occur in natural populations. Tetraploids probably have arisen from syngamy of diploid eggs and diploid sperm produced by diploid hybrid males. Diploid hybrid males may therefore play a significant role in the dynamics of the complex, starting the evolutionary process that may ultimately lead to a new sexually reproducing species.

Spatial genetic and clonal structure in Maianthemum dilatatum as defined by AFLP markers

2005 ◽  
Vol 83 (9) ◽  
pp. 1126-1132 ◽  
Author(s):  
Amy S.G. Wilson ◽  
Bart J. van der Kamp ◽  
Carol Ritland
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Clonal Growth ◽  
Spatial Genetic Structure ◽  
Restricted Gene Flow ◽  
Clonal Structure ◽  
Length Polymorphisms ◽  
Amplified Fragment Length Polymorphisms ◽  
Flow Processes ◽  
Low Levels

Amplified fragment length polymorphisms (AFLPs) were used to investigate the clonal and spatial genetic structure of Maianthemum dilatatum (A. Wood) Nels. & J.F. Macbr. (Convallariaceae), a clonal rhizomatous herb, which can form large patches of continuous cover. Within a subpopulation covering approximately 3 ha, all patches (n = 21) were mapped and sampled. Within these patches, 116 ramets were sampled and assigned to 74 putative genets. Small patches appeared to be single genets while larger patches were genetically heterogeneous and only moderately differentiated (ΦST = 0.291, p = 0.001). Less intense sampling in other populations produced similar results in that single genet populations were not found. Evidence of genet natality was present with the detection of five yearlings within a single season. Spatial autocorrelation measures detected spatial genetic structure attributable to both clonal growth and gene flow processes. It was concluded that within M. dilatatum populations, clonality is a significant factor, but the spatial structuring of genetic variation suggests that both low levels of restricted gene flow and repeated recruitment of genets occur.

Expression of the cell adhesion molecules on leukocytes that demarginate during acute maximal exercise

1999 ◽  
Vol 86 (3) ◽  
pp. 970-976 ◽  
Author(s):  
Stephan F. van Eeden ◽  
John Granton ◽  
Jennifer M. Hards ◽  
Barbara Moore ◽  
James C. Hogg
Keyword(s):  
Fluorescence Intensity ◽  
Mean Fluorescence Intensity ◽  
Maximal Exercise ◽  
Flow Cytometric Analysis ◽  
Cycle Ergometer ◽  
Phenotypic Characteristics ◽  
Flow Cytometric ◽  
The Mean ◽  
Low Levels

The pulmonary vascular bed is an important reservoir for the marginated pool of leukocytes that can be mobilized by exercise or catecholamines. This study was designed to determine the phenotypic characteristics of leukocytes that are mobilized into the circulation during exercise. Twenty healthy volunteers performed incremental exercise to exhaustion [maximal O2consumption (V˙o2 max)] on a cycle ergometer. Blood was collected at baseline, at 3-min intervals during exercise, atV˙o2 max, and 30 min after exercise. Total white cell, polymorphonuclear leukocyte (PMN), and lymphocyte counts increased with exercise toV˙o2 max( P < 0.05). Flow cytometric analysis showed that the mean fluorescence intensity of L-selectin on PMN (from 14.9 ± 1 at baseline to 9.5 ± 1.6 atV˙o2 max, P < 0.05) and lymphocytes (from 11.7 ± 1.2 at baseline to 8 ± 0.8 atV˙o2 max, P < 0.05) decreased with exercise. Mean fluorescence intensity of CD11b on PMN increased with exercise (from 10.2 ± 0.6 at baseline to 25 ± 2.5 atV˙o2 max, P < 0.002) but remained unchanged on lymphocytes. Myeloperoxidase levels in PMN did not change with exercise. In vitro studies showed that neither catecholamines nor plasma collected atV˙o2 maxduring exercise changed leukocyte L-selectin or CD11b levels. We conclude that PMN released from the marginated pool during exercise express low levels of L-selectin and high levels of CD11b.

scholarly journals Occasional hybridization between a native and invasiveSeneciospecies in Australia is unlikely to contribute to invasive success

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3630
Author(s):  
Eleanor E. Dormontt ◽  
Peter J. Prentis ◽  
Michael G. Gardner ◽  
Andrew J. Lowe
Keyword(s):  
Seed Set ◽  
Hybrid Seed ◽  
Invasive Potential ◽  
Model Based Clustering ◽  
Hybrid Plants ◽  
Length Polymorphisms ◽  
Amplified Fragment Length Polymorphisms ◽  
Low Levels ◽  
Low Incidence ◽  
Genotype A

BackgroundHybridization between native and invasive species can facilitate introgression of native genes that increase invasive potential by providing exotic species with pre-adapted genes suitable for new environments. In this study we assessed the outcome of hybridization between nativeSenecio pinnatifoliusvar.pinnatifoliusA.Rich. (dune ecotype) and invasiveSenecio madagascariensisPoir. to investigate the potential for introgression of adaptive genes to have facilitatedS. madagascariensisspread in Australia.MethodsWe used amplified fragment length polymorphisms (141 loci) and nuclear microsatellites (2 loci) to genotype a total of 118 adults and 223 seeds fromS. pinnatifoliusvar.pinnatifoliusandS. madagascariensisat one allopatric and two shared sites. We used model based clustering and assignment methods to establish whether hybrid seed set and mature hybrids occur in the field.ResultsWe detected no adult hybrids in any population. Low incidence of hybrid seed set was found at Lennox Head where the contact zone overlapped for 20 m (6% and 22% of total seeds sampled forS. pinnatifoliusvar.pinnatifoliusandS. madagascariensisrespectively). One hybrid seed was detected at Ballina where a gap of approximately 150 m was present between species (2% of total seeds sampled forS. madagascariensis).ConclusionsWe found no evidence of adult hybrid plants at two shared sites. Hybrid seed set from both species was identified at low levels. Based on these findings we conclude that introgression of adaptive genes fromS. pinnatifoliusvar.pinnatifoliusis unlikely to have facilitatedS. madagascariensisinvasions in Australia. Revisitation of one site after two years could find no remainingS. pinnatifoliusvar. pinnatifolius, suggesting that contact zones between these species are dynamic and thatS. pinnatifoliusvar. pinnatifoliusmay be at risk of displacement byS. madagascariensisin coastal areas.

Virulent and avirulent Entamoeba histolytica and E. dispar differ in their cell surface phosphorylated glycolipids

Parasitology ◽  
1997 ◽  
Vol 114 (2) ◽  
pp. 95-104 ◽  
Author(s):  
S. MOODY ◽  
S. BECKER ◽  
Y. NUCHAMOWITZ ◽  
D. MIRELMAN
Keyword(s):  
Entamoeba Histolytica ◽  
Polyclonal Antibodies ◽  
Virulent Strain ◽  
Flow Cytometric Analysis ◽  
Structural Features ◽  
Surface Distribution ◽  
Flow Cytometric ◽  
Virulent Strains ◽  
Low Levels ◽  
Modified Forms

Virulent strains of Entamoeba histolytica have been reported to produce a mixture of phosphoglycoconjugates that share some structural features with the lipophosphoglycans (LPGs) of Leishmania. Purification of these glycoconjugates is essential to their precise structural characterization. In this study we have extracted ‘LPG-like’ molecules from various virulent E. histolytica strains and purified on the basis of charge differences, 2 apparently related glycoconjugates a ‘LPG’ and a ‘lipophosphopeptidoglycan (LPPG)’. In marked contrast to the abundance of these ‘LPG’ and ‘LPPG’ molecules in the virulent strains, avirulent E. histolytica and E. dispar strains produce either very low, or no detectable levels of LPG, and either low levels or modified forms of ‘LPPG’. Monospecific polyclonal antibodies prepared against that ‘LPG’ of the virulent strain HM-1: IMSS cl6 identified epitopes shared between both the ‘LPG’ and the ‘LPPG’ of this and other virulent strains, using Western blot analysis. Flow cytometric analysis of a range of strains using these antibodies identified a surface distribution of these molecules and confirmed a correlation between surface exposure of epitopes bound by these antibodies and parasite virulence.

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