hgu2beta7MAP {hgu2beta7} | R Documentation

## Mappings between probe identifiers and cytogenetic maps/bands

### Description

When viewed using a microscope and special stains a chromosome is divided into regions, or cytogenetic bands, of transverse alternating light and dark or fluorescent and nonfluorescent bands. hgu2beta7MAP maps probe identifiers to the labels of cytogenetic bands within chromosomes where genes represented by the probe ids are located

### Details

Cytogenetic bands for most higher organisms are labeled p1, p2, p3, q1, q2, q3 (p and q are the p and q arms), etc., counting from the centromere out toward the telomeres. At higher resolutions, sub-bands can be seen within the bands. The sub-bands are also numbered from the centromere out toward the telomere. Thus, a label of 7q31.2 indicates that the band is on chromosome 7, q arm, band 3, sub-band 1, and sub-sub-band 2.

A given probe id may be mapped to one or more cytogenetic bands depending on whether genes represented by probe ids have only one or more chromosomal locations. Different genes may also be mapped to the same cytogenetic bands.

The physical location of each band on a chromosome can be obtained from another environment named "organism"CYTOLOC in a separate data package for human(humanCHRLOC), mouse(mouseCHRLOC), and rat(ratCHRLOC).

Mappings were based on data provided by:

LocusLink:ftp://ftp.ncbi.nih.gov/refseq/LocusLink/LL_tmpl.gz. Built: February 16, 2005

Package built Wed Feb 16 23:32:20 2005

### References

http://www.ncbi.nlm.nih.gov

### Examples

        # Convert the environment to a list
        xx <- as.list(hgu2beta7MAP)
        # Remove probe ids that do not map to any cytoband
        xx <- xx[!is.na(xx)]
        if(length(xx) > 0){
            # The cytobands for the first two elements of XX
            xx[1:2]
            # Get the first one
            xx[[1]]
        }

[Package hgu2beta7 version 1.2.1 Index]