scholarly journals TRANSLATING ECOLOGY, PHYSIOLOGY, BIOCHEMISTRY, AND POPULATION GENETICS RESEARCH TO MEET THE CHALLENGE OF TICK AND TICK-BORNE DISEASES IN NORTH AMERICA

2016 ◽  
Vol 92 (1) ◽  
pp. 38-64 ◽  
Author(s):  
Maria D. Esteve-Gassent ◽  
Ivan Castro-Arellano ◽  
Teresa P. Feria-Arroyo ◽  
Ramiro Patino ◽  
Andrew Y. Li ◽  
...  
Keyword(s):  
Population Genetics ◽  
North America ◽  
Genetics Research

Geographic patterns of genetic diversity in North American trees: a continent-wide analysis

2021 ◽  
Author(s):  
Andrew V. Gougherty
Keyword(s):  
Genetic Diversity ◽  
Population Genetics ◽  
North America ◽  
North American ◽  
Tree Species ◽  
Geographic Patterns ◽  
Study Characteristics ◽  
Dispersal Traits ◽  
The Last Glacial Maximum ◽  
The Last Glacial

In the northern hemisphere, many species have been reported to have greater genetic diversity in southern populations than northern populations - ostensibly due to migration northward following the last glacial maximum (LGM). The generality of this pattern, while well-established for some taxa, remains unclear for North American trees. To address this issue, I collected published population genetics data for 73 North American tree species, and tested whether genetic diversity was associated with latitude or longitude and whether geographic trends were associated with dispersal traits, range or study characteristics. I found there were no general geographic patterns in genetic diversity, and the strength of the geographic gradients were not associated with any species or study characteristics. Species in the northern and western regions of North America tended to have more species with genetic diversity that declined with latitude, but most species had no significant trend. This work shows that North American trees have complex, individualistic, patterns of genetic diversity that may negate explanation by any particular dispersal trait or range characteristic.

Genetically stable, individual-specific differences in hypervariable DNA in Norway spruce, detected by hybridization to a phage M13 probe

1992 ◽  
Vol 22 (1) ◽  
pp. 117-123 ◽  
Author(s):  
Anders Kvarnheden ◽  
Peter Engström
Keyword(s):  
Population Genetics ◽  
Norway Spruce ◽  
Repeat Sequence ◽  
Breeding Programs ◽  
Genetics Research ◽  
Bacteriophage M13 ◽  
Order Of Magnitude ◽  
Individual Trees ◽  
Hypervariable Loci ◽  
M13 Probe

DNA fingerprinting techniques have significantly improved the resolution of the analysis of genetic polymorphisms in major eukaryotic taxa. The techniques are based on the use of specific DNA probes, which hybridize to families of related minisatellite loci that are dispersed in the genomes of a range of eukaryotes. These sequences are highly variable as a result of a variation in the numbers of a core repeat sequence at each locus. We wanted to establish whether one such probe, the DNA of the bacteriophage M13, could be used to detect hypervariable loci in the conifer Norway spruce, Piceaabies (L.) Karst., and to examine if the method could detect genetic differences at the level of populations and (or) individual trees. The results show that hypervariable minisatellite sequences that hybridize to the M13 probe are present in Norway spruce. The minisatellite sequences are stably inherited, and the variability within the species is sufficiently high to allow the distinction of different individuals. The differences between populations are of the same order of magnitude as those between trees within populations. The method is potentially useful in population genetics research on conifers, as well as in breeding programs.

scholarly journals Genetic Diversity and Population Genetics of Mosquitoes (Diptera: Culicidae:Culexspp.) from the Sonoran Desert of North America

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Edward Pfeiler ◽  
Carlos A. Flores-López ◽  
Jesús Gerardo Mada-Vélez ◽  
Juan Escalante-Verdugo ◽  
Therese A. Markow
Keyword(s):  
Genetic Diversity ◽  
Population Genetics ◽  
North America ◽  
Sonoran Desert ◽  
Phylogenetic Analyses ◽  
Gene Segment ◽  
Population Expansion ◽  
The Other ◽  
Coi Gene ◽  
Unidentified Species

The population genetics and phylogenetic relationships ofCulexmosquitoes inhabiting the Sonoran Desert region of North America were studied using mitochondrial DNA and microsatellite molecular markers. Phylogenetic analyses of mitochondrial cytochromecoxidase subunit I (COI) from mosquitoes collected over a wide geographic area, including the Baja California peninsula, and mainland localities in southern Arizona, USA and Sonora, Mexico, showed several well-supported partitions corresponding toCx. quinquefasciatus, Cx. tarsalis,and two unidentified species,Culexsp. 1 and sp. 2.Culex quinquefasciatuswas found at all localities and was the most abundant species collected.Culex tarsaliswas collected only at Tucson, Arizona and Guaymas, Sonora. The two unidentified species ofCulexwere most abundant at Navojoa in southern Sonora. Haplotype and nucleotide diversities in the COI gene segment were substantially lower inCx. quinquefasciatuscompared with the other three species. Analysis of molecular variance revealed little structure among seven populations ofCx. quinquefasciatus, whereas significant structure was found between the two populations ofCx. tarsalis. Evidence for an historical population expansion beginning in the Pleistocene was found forCx. tarsalis. Possible explanations for the large differences in genetic diversity betweenCx. quinquefasciatusand the other species ofCulexare presented.

Genetic epidemiology 1: behavioural genetics

2003 ◽  
pp. 317-334
Author(s):  
Frühling Rijsdijk ◽  
Pak Sham
Keyword(s):  
Population Genetics ◽  
Environmental Factors ◽  
Genetic Basis ◽  
Genetic Factors ◽  
Genetic Mutation ◽  
Mendelian Inheritance ◽  
Behavioural Genetics ◽  
Mendelian Disorders ◽  
Genetics Research ◽  
Genetic And Environmental Factors

Behavioural genetics is the study of the genetic basis of behavioural traits including both psychiatric disorders and ‘normal’ personality dimensions. Behavioural genetics derives its theoretical basis from population genetics. Soon after the laws of Mendelian inheritance were re-discovered in 1900, the implications of these laws on the genetic properties of populations were worked out. Such properties include segregation ratios, genotypic frequencies in random mating populations, the effect of population structure and systems of mating, the impact of selection, the partitioning of genetic variance, and the genetic correlation between relatives. Some appreciation of population genetics is necessary for a deep understanding of behavioural genetics. Because of the complexity of behavioural traits, genetic factors cannot be regarded in isolation, or as static. Instead, it is important to consider: (i) the relative contributions of genetic and environmental factors, (ii) the interplay between genetic and environmental factors, and (iii) the changing role of genetic factors in different stages of development from infancy to old age. The major study designs in behavioural genetics will be discussed in this chapter, namely family studies, twin studies, and adoption studies. Behavioural genetics, augmented by molecular genetics has the potential to identify specific genetic variants which influence behaviour. This will be considered in detail in Chapter 14. Mendelian inheritance Gregor Mendel first demonstrated the genetic basis of biological inheritance by studies of simple all-or-none traits in the garden pea. These traits were particularly revealing because they were completely determined by the genotype at a single chromosomal locus. Diseases caused by genetic mutation at a single locus are commonly called Mendelian or single-gene disorders. A dominant disorder is expressed when an individual has one or two copies of the mutant allele, whereas a recessive disorder is expressed only when both alleles at the locus are the mutant variant. Examples of Mendelian disorders of clinical significance in psychiatry are Huntington's disease and fragile X syndrome. Mendelian disorders tend to be relatively rare because they are usually subjected to severe negative selective pressure, due to their increased mortality. Most common disorders and continuous traits of interest in psychiatry have an aetiology involving multiple genetic and environmental factors. Categorical and dimensional traits Behavioural genetics is rooted in both psychiatry and psychology. Psychiatrists traditionally adopt a medical model where diseases are defined as categorical entities and diagnoses are either present or absent. Psychologists on the other hand prefer quantitative measures of cognitive ability, personality and other traits. The methodology of behavioural genetics research reflects this duality, although there is a trend to integrate the two approaches, especially for traits such as anxiety and depression where both diagnostic criteria and quantitative measures exist.

Population genetics and phylogeography of freshwater mussels in North America,Elliptio dilatataandActinonaias ligamentina(Bivalvia: Unionidae)

2008 ◽  
Vol 17 (9) ◽  
pp. 2149-2163 ◽  
Author(s):  
CURT L. ELDERKIN ◽  
ALAN D. CHRISTIAN ◽  
JANICE L. METCALFE-SMITH ◽  
DAVID J. BERG
Keyword(s):  
Population Genetics ◽  
North America ◽  
Freshwater Mussels
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