Lecture 11 Sex Chromosome Haplotyping & Gender Identification

Y Chromosome

The sex chromosome that is patrilineal and encodes genes for sex determination and spermatogenesis.

Pseudoautosomal Regions (PARs)

Homologous nucleotide sequences on X and Y chromosomes that allow for proper segregation during meiosis.

Male-Specific Region (MSY)

The part of the Y chromosome that does not undergo homologous recombination and includes both heterochromatic and euchromatic regions.

Y-STR

Y chromosome Short Tandem Repeats used for DNA testing, particularly in forensic cases.

Amelogenin (AMEL)

The most common sex-typing marker used in multiplex PCR systems for sex determination.

Polymorphic Sequences

Variations in the Y chromosome that serve as markers for DNA testing, particularly Y-STRs.

Intrachromosomal Gene Conversion

Non-reciprocal transfer of DNA between repeated genes on a single chromosome.

Sex Typing

The identification of victim and perpetrator DNA evidence in cases like sexual assault.

Core Y-STR Loci

Specific locations on the Y chromosome that are commonly analyzed for forensic purposes.

Rapidly Mutating Y-STR (RM Y-STR)

Y-STRs that have high mutation rates and improve resolution in patrilineage determination.

Electropherogram

A graphical representation of the DNA profile displaying genotypes of Y-STR loci.

DYF155S1

The first characterized Y chromosome minisatellite that is highly polymorphic.

SRY Gene

The sex-determining region Y gene that plays a role in male development and is located on the Y chromosome.

Testis-Specific Protein Y (TSPY)

A gene present on the Y chromosome with multiple copies, contributing to high detection sensitivity in sex typing.

Cytogenetic Map

A representation of the structure of chromosomes, including the positions of various loci.

X-STR Profiling

The process of analyzing X-chromosomal Short Tandem Repeats, useful in kinship testing.

DYS Loci

A designation for Y chromosome loci used in forensics, including various repeat motifs.

Electrophoresis

A laboratory technique used to separate DNA fragments based on their size, often used in sex-typing.

Y-STR Mixtures

Samples containing both female and male DNA where Y chromosome loci can be analyzed to identify male contributors.

Sex-Typing Markers

Genetic markers used to distinguish between sexes based on chromosomal differences.