Y-STR

Last updated
STR rate ranges as of 2008 for 16 Y-STRs
STR
site
Mutation rate (x 10−3)
LB-96%CI'rate'UB-96%CINotes
DYS191.52.43.523 of 9658
DYS3851.42.13.031 of 14896
DYS389I0.951.83.014 of 7862
DYS389II1.82.84.222 of 7849
DYS3901.42.33.521 of 9140
DYS3912.03.04.528 of 9089
DYS3920.180.551.35 of 9053
DYS3930.360.891.87 of 7842
DYS4370.601.53.17 of 4672
DYS4380.0510.431.52 of 4709
DYS4393.85.78.427 of 4686
DYS4480.191.65.72 of 1258
DYS4561.84.8106 of 1258
DYS4582.86.4128 of 1258
DYS6351.63.87.48 of 2131
GATA H4.10.712.25.15 of 2294
From table 1. Sanchez-Diz et al. 2008.
Note some of the N in the 17 STR are quite low in frequency

A Y-STR is a short tandem repeat (STR) on the Y-chromosome. Y-STRs are often used in forensics, paternity, and genealogical DNA testing. Y-STRs are taken specifically from the male Y chromosome. These Y-STRs provide a weaker analysis than autosomal STRs because the Y chromosome is only found in males, which are only passed down by the father, making the Y chromosome in any paternal line practically identical. This causes a significantly smaller amount of distinction between Y-STR samples. Autosomal STRs provide a much stronger analytical power because of the random matching that occurs between pairs of chromosomes during the zygote-making process. [1]

Contents

Nomenclature

Y-STRs are assigned names by the HUGO gene nomenclature committee (HGNC).

Some testing companies have different formats for the way STR markers are written. For example, the marker DYS455 may be written as DYS455, DYS 455, DYS#455, or DYS# 455. The scientific standard accepted by HUGO and NIST is DYS455. [2]

DYS

DYS is a variation on the jargon used in human autosomal STR testing where the second character is typically reserved for the chromosome number (e.g. D8S1179).

D = DNA
Y = Y-chromosome
S = (unique) segment

Y-STR analysis

There are regions on DNA that are made up of multiple copies of short repeating sequences of bases (for example TATT) which repeat a variable number of times depending on the individual. These regions, called "variable number short tandem repeats", are what is looked at when performing STR analysis. The likelihood of two people having the same number of repeated sequences is extremely small, and becomes even smaller the more regions that are analyzed. This makes up the basis of short tandem repeat analysis. [1] The cornerstone for this process, however, is polymerase chain reaction (PCR). This allows forensic scientists to make millions of copies of the STR regions. Gel electrophoresis then "yields the number of times each repeat unit appears in the fragment." This allows for easy comparison of DNA. [3]

STRs and forensics

In the United States, 13 different autosomal STR loci are used as a basis of analysis for forensic purposes. If crime scene DNA is ample and all 13 autosomal loci accessible, the likelihood of two unrelated people matching the same sample is around one in one billion. [1]

The basis for the profile probability estimation for Y-STR analysis is the counting method. [4] The application of a confidence interval accounts for database size and sampling variation. The Y haplotype frequency (p) is calculated using the p = x/N formula, where x is equal to the number of times the haplotype is observed in a database containing N number of haplotypes. For example, if a haplotype has been observed twice in a database of N = 2000, the frequency of that haplotype will be: 2/2000 = 0.001. Reporting a Y haplotype frequency, without a confidence interval, is acceptable but only provides a factual statement regarding observations of a Y haplotype in the database. An upper confidence limit for the probability of the Y haplotype in the population should be calculated using the method described by Clopper and Pearson (1934). [5] This uses the binomial distribution for the probabilities of counts, including zero or other small numbers that are found for Y haplotypes.

Databases

Forensic databases (without individual information, for frequency purposes):

In genetic genealogy, Ysearch used to be the last sponsored database containing publicly submitted surnames and Y-STR haplotypes until its decommission on May 24, 2018, preceding by a day the implementation of the General Data Protection Regulation in the European Union, following a prolonged period of lacking support from its creator, Family Tree DNA. The database was founded in 2003 and reached 219 thousand records (among which 152 thousand unique haplotypes) before its shutdown. Other similar databases had disappeared earlier. [7] [8]

Haplogroup (Y-SNP) specific data:

See also

Related Research Articles

A microsatellite is a tract of repetitive DNA in which certain DNA motifs are repeated, typically 5–50 times. Microsatellites occur at thousands of locations within an organism's genome. They have a higher mutation rate than other areas of DNA leading to high genetic diversity. Microsatellites are often referred to as short tandem repeats (STRs) by forensic geneticists and in genetic genealogy, or as simple sequence repeats (SSRs) by plant geneticists.

<span class="mw-page-title-main">Haplotype</span> Group of genes from one parent

A haplotype is a group of alleles in an organism that are inherited together from a single parent.

Genetic genealogy is the use of genealogical DNA tests, i.e., DNA profiling and DNA testing, in combination with traditional genealogical methods, to infer genetic relationships between individuals. This application of genetics came to be used by family historians in the 21st century, as DNA tests became affordable. The tests have been promoted by amateur groups, such as surname study groups or regional genealogical groups, as well as research projects such as the Genographic Project.

A genealogical DNA test is a DNA-based genetic test used in genetic genealogy that looks at specific locations of a person's genome in order to find or verify ancestral genealogical relationships, or to estimate the ethnic mixture of an individual. Since different testing companies use different ethnic reference groups and different matching algorithms, ethnicity estimates for an individual vary between tests, sometimes dramatically.

Second Generation Multiplex Plus (SGM Plus), is a DNA profiling system developed by Applied Biosystems. It is an updated version of Second Generation Multiplex. SGM Plus has been used by the UK National DNA Database since 1998.

A surname DNA project is a genetic genealogy project which uses genealogical DNA tests to trace male lineage.

<span class="mw-page-title-main">STR analysis</span> Biological DNA analysis for allele repeats

Shorttandemrepeat (STR) analysis is a common molecular biology method used to compare allele repeats at specific loci in DNA between two or more samples. A short tandem repeat is a microsatellite with repeat units that are 2 to 7 base pairs in length, with the number of repeats varying among individuals, making STRs effective for human identification purposes. This method differs from restriction fragment length polymorphism analysis (RFLP) since STR analysis does not cut the DNA with restriction enzymes. Instead, polymerase chain reaction (PCR) is employed to discover the lengths of the short tandem repeats based on the length of the PCR product.

In genetic genealogy, a unique-event polymorphism (UEP) is a genetic marker that corresponds to a mutation that is likely to occur so infrequently that it is believed overwhelmingly probable that all the individuals who share the marker, worldwide, will have inherited it from the same common ancestor, and the same single mutation event.

<span class="mw-page-title-main">Haplogroup T-M184</span> Human Y-chromosome DNA haplogroup

Haplogroup T-M184, also known as Haplogroup T, is a human Y-chromosome DNA haplogroup. The unique-event polymorphism that defines this clade is the single-nucleotide polymorphism known as M184.

The Sorenson Molecular Genealogy Foundation (SMGF) was an independent DNA and genealogical research institution with the goal of demonstrating how the peoples of the world are related. SMGF collected DNA samples and genealogical information from individuals across the globe to establish these connections.

<span class="mw-page-title-main">Earth Human STR Allele Frequencies Database</span>

The Earth Human STR Allele Frequencies Database is a scientific project based on a dynamic web interface and a relational database management system. Its main purpose is the management of STR populational data reported from all over the world, providing highly specialized population genetics tools and also an overview of world population genetic structure at global scale.

In paternity testing, Paternity Index (PI) is a calculated value generated for a single genetic marker or locus and is associated with the statistical strength or weight of that locus in favor of or against parentage given the phenotypes of the tested participants and the inheritance scenario. Phenotype typically refers to physical characteristics such as body plan, color, behavior, etc. in organisms. However, the term used in the area of DNA paternity testing refers to what is observed directly in the laboratory. Laboratories involved in parentage testing and other fields of human identity employ genetic testing panels that contain a battery of loci each of which is selected due to extensive allelic variations within and between populations. These genetic variations are not assumed to bestow physical and/or behavioral attributes to the person carrying the allelic arrangement(s) and therefore are not subject to selective pressure and follow Hardy Weinberg inheritance patterns.

Genetic studies on Serbs show close affinity to other neighboring South Slavs.

<span class="mw-page-title-main">Y Chromosome Haplotype Reference Database</span>

The Y Chromosome Haplotype Reference Database (YHRD) is an open-access, annotated collection of population samples typed for Y chromosomal sequence variants. Two important objectives are pursued: (1) the generation of reliable frequency estimates for Y-STR haplotypes and Y-SNP haplotypes to be used in the quantitative assessment of matches in forensic and kinship cases and (2) the characterization of male lineages to draw conclusions about the origins and history of human populations. The database is endorsed by the International Society for Forensic Genetics (ISFG). By May 2023 about 350.000 Y chromosomes typed for 9-29 STR loci have been directly submitted by worldwide forensic institutions and universities. In geographic terms, about 53% of the YHRD samples stem from Asia, 21% from Europe, 12% from North America, 10% from Latin America, 3% from Africa, 0.8% from Oceania/Australia and 0.2% from the Arctic. The 1.406 individual sampling projects are described in about 800 peer-reviewed publications

Population genetics is a scientific discipline which contributes to the examination of the human evolutionary and historical migrations. Particularly useful information is provided by the research of two uniparental markers within our genome, the Y-chromosome (Y-DNA) and mitochondrial DNA (mtDNA), as well as autosomal DNA. The data from Y-DNA and autosomal DNA suggests that the Croats mostly are descendants of the Slavs of the medieval migration period, according to mtDNA have genetic diversity which fits within a broader European maternal genetic landscape, and overall have a uniformity with other South Slavs from the territory of former Yugoslavia.

Haplogroup T-L206, also known as haplogroup T1, is a human Y-chromosome DNA haplogroup. The SNP that defines the T1 clade is L206. The haplogroup is one of two primary branches of T (T-M184), the other subclade being T2 (T-PH110).

As with all modern European nations, a large degree of 'biological continuity' exists between Bosnians and Bosniaks and their ancient predecessors with Y chromosomal lineages testifying to predominantly Paleolithic European ancestry. Studies based on bi-allelic markers of the NRY have shown the three main ethnic groups of Bosnia and Herzegovina to share, in spite of some quantitative differences, a large fraction of the same ancient gene pool distinct for the region. Analysis of autosomal STRs have moreover revealed no significant difference between the population of Bosnia and Herzegovina and neighbouring populations.

<span class="mw-page-title-main">Forensic DNA analysis</span>

DNA profiling is the determination of a DNA profile for legal and investigative purposes. DNA analysis methods have changed countless times over the years as technology changes and allows for more information to be determined with less starting material. Modern DNA analysis is based on the statistical calculation of the rarity of the produced profile within a population.

References

  1. 1 2 3 "STR Analysis"
  2. "Y-STR Fact Sheets".
  3. "A New Breed of High-Tech Detectives"
  4. "SWGDAM Interpretation Guidelines for Y-Chromosome STR Typing"
  5. Clopper, C. and Pearson, E. The use of confidence or fiducial limits illustrated in the case of binomial, Biometrika (1934) 26:404-413.
  6. Roewer, Sascha Willuweit and Lutz. "YHRD : Y-Chromosome STR Haplotype Reference Database". yhrd.org.
  7. Estes, Roberta (May 14, 2018). "World Families Network, Ysearch and Mitosearch Bite the Dust – Thanks So Much GDPR". DNAeXplained - Genetic Genealogy.
  8. "Ysearch".

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