Molecular markers in genetic studies and breeding

2014 ◽  
Vol 4 (3) ◽  
pp. 236-244 ◽  
Author(s):  
E. K. Khlestkina
Keyword(s):  
Molecular Markers ◽  
Genetic Studies

scholarly journals Biology of Nodal Spread in Colon Cancer: Insights from Molecular and Genetic Studies

2018 ◽  
Vol 59 (5-6) ◽  
pp. 361-370 ◽  
Author(s):  
Pridvi Kandagatla ◽  
Lilias H. Maguire ◽  
Karin M. Hardiman
Keyword(s):  
Colorectal Cancer ◽  
Colon Cancer ◽  
Molecular Markers ◽  
Lymph Node ◽  
Genetic Heterogeneity ◽  
Genetic Studies ◽  
Potential Models ◽  
Node Metastasis ◽  
Node Metastases ◽  
Nodal Spread

Colorectal cancer (CRC) lymph node metastases are common but their genetics and the mechanism whereby these metastases occur are not well understood. Here we present recent data regarding genetic heterogeneity in primary CRCs and their metastasis. In addition, we explain the different potential models describing the mechanisms of metastasis and the data supporting them. Multiple studies have also revealed a variety of prognostic molecular markers that are associated with lymph node metastasis in CRC. A better understanding of genetic heterogeneity and the mechanisms of metastasis is critical to predicting clinical response and resistance to targeted therapy.

Genetic perspectives on invasions: the case of the Cladocera

2002 ◽  
Vol 59 (7) ◽  
pp. 1229-1234 ◽  
Author(s):  
Paul D.N Hebert ◽  
Melania E.A Cristescu
Keyword(s):  
Molecular Markers ◽  
Molecular Identification ◽  
Genetic Divergence ◽  
Invasion Biology ◽  
Genetic Studies ◽  
Genetic Analyses ◽  
Species Invasions ◽  
Historical Levels ◽  
Natural Incidence ◽  
Dna Bar Coding

Using freshwater cladocerans as an example, this paper explores the contributions that genetic analyses are making to the field of invasion biology. Most importantly, this approach enables a quantification of the incidence of both recent and past invasions. By determining genetic divergence between European and North American lineages of cladocerans, it is possible to estimate the natural incidence of past exchange between these continents. The results of this analysis establish that the current pace of species invasions is extraordinary; present rates are nearly 50 000 times higher than historical levels. Genetic studies can also exploit molecular markers to localize the points of origin of invaders. Finally, genetic studies are poised to play an important role in monitoring invasions; the DNA bar-coding of life is now simple and rapid enough to enable the development of molecular identification systems.

scholarly journals Estimation of Molecular Pairwise Relatedness in Autopolyploid Crops

2020 ◽  
Vol 10 (12) ◽  
pp. 4579-4589 ◽  
Author(s):  
Rodrigo R. Amadeu ◽  
Leticia A. C. Lara ◽  
Patricio Munoz ◽  
Antonio A. F. Garcia
Keyword(s):  
Molecular Markers ◽  
Molecular Marker ◽  
Close Relationships ◽  
R Package ◽  
Molecular Data ◽  
Genetic Studies ◽  
Ploidy Levels ◽  
Lower Performance

A suitable pairwise relatedness estimation is key to genetic studies. Several methods are proposed to compute relatedness in autopolyploids based on molecular data. However, unlike diploids, autopolyploids still need further studies considering scenarios with many linked molecular markers with known dosage. In this study, we provide guidelines for plant geneticists and breeders to access trustworthy pairwise relatedness estimates. To this end, we simulated populations considering different ploidy levels, meiotic pairings patterns, number of loci and alleles, and inbreeding levels. Analysis were performed to access the accuracy of distinct methods and to demonstrate the usefulness of molecular marker in practical situations. Overall, our results suggest that at least 100 effective biallelic molecular markers are required to have good pairwise relatedness estimation if methods based on correlation is used. For this number of loci, current methods based on multiallelic markers show lower performance than biallelic ones. To estimate relatedness in cases of inbreeding or close relationships (as parent-offspring, full-sibs, or half-sibs) is more challenging. Methods to estimate pairwise relatedness based on molecular markers, for different ploidy levels or pedigrees were implemented in the AGHmatrix R package.

On the identity of Spio filicornis (O.F. Müller, 1776)—with the designation of a neotype, and the description of two new species from the North East Atlantic Ocean based on morphological and genetic studies

Zootaxa ◽  
2011 ◽  
Vol 2815 (1) ◽  
pp. 1 ◽  
Author(s):  
KARIN MEIßNER ◽  
ANDREAS BICK ◽  
RALF BASTROP
Keyword(s):  
Molecular Markers ◽  
New Species ◽  
Genetic Divergence ◽  
18S Rdna ◽  
Original Description ◽  
East Atlantic ◽  
Genetic Studies ◽  
North East ◽  
The North ◽  
Two New Species

The aim of this study is to solve taxonomic problems pertaining to Spio filicornis (O.F. Müller, 1776). The original description by O. F. Müller was very brief and type material was not deposited. Based on the literature the confusion about the identity of the species has been tremendous; e.g., it was only recently realized that at least two different species from the North and Baltic Seas could be identified as S. filicornis (Bick et al. 2010). The present study is based on material collected by the authors in 2009 at the type locality in Iluilârssuk, near Paamiut, SW Greenland. Spio filicornis is redescribed in detail and illustrated comprehensively. A neotype has been designated and deposited in the collection of Rostock University. Species formerly referred to as S. cf. filicornis from the North and Baltic Seas (Bick et al. 2010) are formally described as two new species, Spio arndti sp. nov., and S. symphyta sp. nov. The morphological diagnostic characters within Spio are discussed. Information on three molecular markers (16S rDNA, 18S rDNA, cytochrome c oxidase subunit I) is also provided. The genetic divergence between the three Spio species corroborates the taxonomic discrimination.

scholarly journals Does Primula intricata Gren. et Godr. Merit Species Rank? A Taxonomic Revision Based on nrDNA, cpDNA and AFLP Data

2011 ◽  
Vol 39 (1) ◽  
pp. 24
Author(s):  
Dana ŞUTEU ◽  
Mihai PUSCAS ◽  
Ioan BĂCILĂ ◽  
Ana COSTE ◽  
Liviu FILIPAS ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Taxonomic Status ◽  
Taxonomic Revision ◽  
Distinct Species ◽  
Nuclear Ribosomal Dna ◽  
Valid Species ◽  
Aflp Data ◽  
Genetic Studies ◽  
Length Polymorphisms ◽  
Amplified Fragment Length Polymorphisms

Primula intricata Gren. et Godr. has an unclear taxonomic status: it was originally described as a distinct species but subsequently was considered a subspecies (Primula elatior subsp. intricata) or even a variety (P. elatior var. intricata ) of Primula elatior (L.) Hill. No prior genetic studies were performed on this group of Primulaceae, therefore we considered useful to investigate taxonomies boundaries within the P. elatior-intricata group. We explored genetic differences between Primula intricata and Primula elatior group by applying three different types of molecular markers: nuclear ribosomal DNA (ITS1), chloroplast DNA (spacer trnH-psbA and intron trnL) and Amplified Fragment Length Polymorphisms (AFLP). We found a solid differentiation between P. intricata and P. elatior group, differentiation that was confirmed by all the employed molecular markers. This finding enabled us to propose a valid species rank for Primula intricata, as a separate taxon from the P. elatior group.

The development of codominant PCR/RFLP based markers for the flax rust-resistance alleles at the L locus

Genome ◽  
1999 ◽  
Vol 42 (1) ◽  
pp. 1-8 ◽  
Author(s):  
G Hausner ◽  
K Y Rashid ◽  
E O Kenaschuk ◽  
J D Procunier
Keyword(s):  
Molecular Markers ◽  
Nucleotide Sequence ◽  
Marker Assisted Selection ◽  
Rust Resistance ◽  
Single Gene ◽  
Pcr Markers ◽  
Genetic Studies ◽  
New Genes ◽  
Pcr Rflp ◽  
Primer Sets

The flax L locus exists as a single gene with at least 13 alleles with different rust-resistance specificities. With regards to resistance to North American races of flax rust the L2, L6, and L11 alleles are of major importance. Molecular markers have been developed by screening primer sets, whose sequences were based on the nucleotide sequence of L6, for their ability to amplify segments of the L gene. One primer combination was found to amplify only the L6 or L11 alleles and another primer set was found to amplify the 3' end of all important L alleles. The latter primer set yielded a 1.3 kb fragment which upon digestion with the endonuclease MboI generated RFLP patterns unique to L2, L6, L9, and L11. The application of PCR markers to a set of 22 cultivars, comprised of deregistered, recent, and yet to be released cultivars verifies genetic studies done by previous workers and demonstrates the usefulness of the markers for following segregation of L alleles in crosses amongst wide or narrow selections of cultivars. Overall, the results confirmed that L6 is present in many Canadian flax cultivars. However, in several recently-released flax cultivars that have rust resistance conditioned by genes at other loci, the L9 allele was detected. These molecular markers will be useful in marker-assisted selection and the introduction of new genes for rust resistance in the flax breeding programs.Key words: flax rust, PCR/RFLP marker, marker-assisted selection.

scholarly journals Peterhof collection of rye and its use in genetic studies

2018 ◽  
Vol 16 (2) ◽  
pp. 40-49 ◽  
Author(s):  
Anatoly V. Voylokov ◽  
Svetlana P. Sosnikhina ◽  
Natalia D. Tikhenko ◽  
Natalia V. Tsvetkova ◽  
Elena I. Mikhailova ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Genetic Control ◽  
Morphological Traits ◽  
Associate Professor ◽  
Initial Material ◽  
Genetic Studies ◽  
Interspecific Incompatibility ◽  
Qualitative And Quantitative ◽  
Self Compatibility ◽  
Fundamental Research

The article provides information about the history and methods of development of “Peterhof” rye genetic collection, founded by V.S. Fedorov, Associate Professor of the Leningrad University. Isolation of self-compatible mutants, their crosses with self-incompatible rye plants, and subsequent self-pollination of hybrids allowed to reveal the allele diversity in heterogeneous and heterozygous rye varieties. In the course of genetic collection assembly the study of inheritance of qualitative and quantitative morphological traits, genetic control of self-compatibility, genetics of meiosis, genetics of interspecific incompatibility was performed. The corresponding genes were identified and, in most cases, mapped using isozymes and molecular markers. Fundamental research was introduced into practical breeding. Under the direction of V. S. Fedorov, and V. G. Smirnov the first in Russia tetraploid rye variety Leningradskaja Tetra was produced. Currently, based on the study of the genetics of self-fertility, the initial material is being obtained and used for improving rye population varieties. The possibility of using the genetic collection of rye to solve the fundamental problems of plant genetics is discussed.

scholarly journals Genetic Studies in Pea and Apple: The Yin and Yang of Mapping in Plants

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 749C-749
Author(s):  
N.F. Weeden
Keyword(s):  
Molecular Markers ◽  
Recombinant Inbred ◽  
Critical Factor ◽  
Linkage Maps ◽  
Genetic Studies ◽  
Yin And Yang ◽  
Inbred Populations ◽  
Selection Of

Linkage maps consisting primarily of molecular markers have been constructed in pea and apple. Different approaches have been taken to generate these maps. For pea, F2 and recombinant inbred populations have been used to study segregating loci, and a critical factor has been the selection of sufficiently divergent inbred parents for the crosses. In contrast, a double pseudotestcross format has been used in apple, and virutally every variety possesses sufficient heterozygosity to permit the development of a map by examination of the F1. Markers have been identified for many genes in each crop.

On the identity of Spio filicornis (O.F. Müller, 1776)—with the designation of a neotype, and the description of two new species from the North East Atlantic Ocean based on morphological and genetic studies

Zootaxa ◽  
2011 ◽  
Vol 2815 (1) ◽  
Author(s):  
KARIN MEIßNER ◽  
ANDREAS BICK ◽  
RALF BASTROP
Keyword(s):  
Molecular Markers ◽  
New Species ◽  
Genetic Divergence ◽  
18S Rdna ◽  
Original Description ◽  
East Atlantic ◽  
Genetic Studies ◽  
North East ◽  
The North ◽  
Two New Species

The aim of this study is to solve taxonomic problems pertaining to Spio filicornis (O.F. Müller, 1776). The original description by O. F. Müller was very brief and type material was not deposited. Based on the literature the confusion about the identity of the species has been tremendous; e.g., it was only recently realized that at least two different species from the North and Baltic Seas could be identified as S. filicornis (Bick et al. 2010). The present study is based on material collected by the authors in 2009 at the type locality in Iluilârssuk, near Paamiut, SW Greenland. Spio filicornis is redescribed in detail and illustrated comprehensively. A neotype has been designated and deposited in the collection of Rostock University. Species formerly referred to as S. cf. filicornis from the North and Baltic Seas (Bick et al. 2010) are formally described as two new species, Spio arndti sp. nov., and S. symphyta sp. nov. The morphological diagnostic characters within Spio are discussed. Information on three molecular markers (16S rDNA, 18S rDNA, cytochrome c oxidase subunit I) is also provided. The genetic divergence between the three Spio species corroborates the taxonomic discrimination.

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