PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 12663551

Neutrality tests using DNA polymorphism from multiple samples.

Haipeng Li·Yunwu Zhang·Ya-Ping Zhang·Yun-Xin Fu
View original source ↗Export metadata ↓

Abstract

The polymorphism of a gene or a locus is studied with increasing frequency by multiple laboratories or the same group at different times. Such practice results in polymorphism being revealed by different samples at different regions of the locus. Tests of neutrality have been widely conducted for polymorphism data but commonly used statistical tests cannot be applied directly to such data. This article provides a procedure to conduct a neutrality test and details are given for two commonly used tests. Applying the two new tests to the chemokine-receptor gene (CCR5) in humans, we found that the hypothesis that all mutations are selectively neutral cannot explain the observed pattern of DNA polymorphism.

Explore related subjects

Chromosome MappingDNAHumansMathematicsModels, GeneticModels, StatisticalPolymorphism, GeneticReceptors, CCR6Receptors, ChemokineWhite PeopleJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Haipeng Li, Yunwu Zhang, Ya-Ping Zhang, Yun-Xin Fu. 2003. Neutrality tests using DNA polymorphism from multiple samples.. https://doi.org/10.1093/genetics%2F163.3.1147

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2026

Mitotic karyotyping and FISH mapping of the gender-specific locus indicate an advanced XY system in Hippophae rhamnoides.

Hippophae rhamnoides ssp. turkestanica, a subdioecious plant inhabiting the cold desert of the Indian Himalaya, has gained immense recognition for its nutritional and medicinal values. In recent years, the plant species has proven to be a suitable system to understand the evolution of dioecy. Despite its biological significance, the cytogenetics of this dioecious plant is unclear due to various conflicting accounts of its X-Y chromosome system, particularly the length of Y-chromosome. In this study, we resolved these ambiguities through comprehensive cytogenetic analyses across diverse western Himalayan populations. Using morphometric analysis and fluorescence in situ hybridization (FISH) with a gender-specific marker (HRMSSR), we confirmed homomorphic XX chromosomes in females and heteromorphic sex-chromosomes in males with a notably smaller Y-chromosome. The investigation also revealed a predominant somatic chromosome number of 2n = 24, although minor deviations (2n = 18, 20, 22) appeared at the seed level. These findings highlight an evolutionarily advanced sex-chromosome system. This first detailed cytogenetic investigation of Himalayan Seabuckthorn provides critical insights into the chromosomal architecture, laying a crucial foundation for future evolutionary, genomic, and conservation studies in the species.

Chromosome Mapping↗
PubMed2007

Methods for linkage disequilibrium mapping in crops.

Linkage disequilibrium (LD) mapping in plants detects and locates quantitative trait loci (QTL) by the strength of the correlation between a trait and a marker. It offers greater precision in QTL location than family-based linkage analysis and should therefore lead to more efficient marker-assisted selection, facilitate gene discovery and help to meet the challenge of connecting sequence diversity with heritable phenotypic differences. Unlike family-based linkage analysis, LD mapping does not require family or pedigree information and can be applied to a range of experimental and non-experimental populations. However, care must be taken during analysis to control for the increased rate of false positive results arising from population structure and variety interrelationships. In this review, we discuss how suitable the recently developed alternative methods of LD mapping are for crops.

Chromosome Mapping↗
PubMed2007

An efficient method for producing an indexed, insertional-mutant library in rice.

Generation of an indexed, saturated, insertional-mutant library is an aid to understanding the functions of genes in an organism. However, 10 years of work by many investigators have not yet yielded such a library in rice. The major reason is that determining the chromosomal locations of a very large number of random insertion mutants by flanking sequence analysis is highly labor intensive, and therefore, libraries that do exist have not been indexed. We report here an efficient procedure to construct an indexed, region-specific, insertional-mutant library of rice. The procedure makes use of efficient long-PCR-based high-throughput indexing, coupled with a random but anchored population of Ds transposants. Long-PCR indexing allows rapid and simultaneous determination of the chromosomal locations of a large number of mutants that surround a particular anchor line, thus converting a random library into an indexed one. Such a library can be used directly, without the need to screen a large random library for a desired mutant plant.

Chromosome Mapping↗