What is Y chromosome polymorphism?
A chromosome polymorphism is defined as the variations in chromosome morphology, including changes in their size, shape and number, which can commonly occur [9,10]. Therefore, the Y chromosome, which is acrocentric and contains a large proportion of heterochromatin, is likely to exhibit morphological changes .
What chromosome is Alu on?
A member of the Alu family of repeated DNA elements has been identified on the long arm of the human Y chromosome, Yq11. This element, referred to as the Y Alu polymorphic (YAP) element, is present at a specific site on the Y chromosome in some humans and is absent in others.
Is the Y chromosome euchromatin or heterochromatin?
The structure of the human Y chromosome (features are shown approximately to scale). The black regions at each end of the Y chromosome are the pseudoautosomal regions, which cross over with homologous sequences on the X chromosome. The gray regions are heterochromatin.
What does the Alu gene do?
Alu elements are responsible for regulation of tissue-specific genes. They are also involved in the transcription of nearby genes and can sometimes change the way a gene is expressed. Alu elements are retrotransposons and look like DNA copies made from RNA polymerase III-encoded RNAs.
What is Alu repetitive sequence?
1. Alu sequences are repetitive DNA. Repetitive DNA accounts for at least 20% of the human genome, and has been classified into several different types that include four principal families of interspersed repeats; Alu, Line 1, MIR and MaLR .
Does the Y chromosome recombine?
They found that human Y chromosome is able to “recombine” with itself, using palindrome base pair sequences. Such a “recombination” is called gene conversion. In the case of the Y chromosomes, the palindromes are not noncoding DNA; these strings of bases contain functioning genes important for male fertility.
Does the Y chromosome go through recombination?
That’s in part because most Y chromosomes do not undergo standard recombination. Typically, genes from the mother and father are shuffled—or, “cross over”—to produce a genetic combination unique to each offspring.
What is Alu insertion?
Alu insertions are ∼300-bp bipartite, primate-specific interspersed repeats derived from 7SL RNA (19). There are over 1.1 million Alu copies in the human genome (1, 3). Of these elements, a small subset is polymorphic in the population such that both insertion and preinsertion (empty) alleles are present (e.g., refs.
Is PV 92 locus polymorphic?
The PV92 lab is based on a polymorphism, or a DNA region that varies from one individual to another. In this case, the polymorphism is due to an insertion, which means that an extra piece of DNA (the ALU transposon) is inserted into the genomes of some people, but not others.
What are Alu sequences an example of?
Alu elements are a type of “jumping gene,” or transposable element (TE), that exists only in primates. Like all TEs, they are discrete DNA sequences that move, or “jump,” from one place on the genome to another, sometimes inserting copies of themselves directly into the middle of protein-coding genes.