Human karyotypes for teaching: (46,XX,der(4)t(4;8)(q35.1;q24.11) These karyotypes are from an abnormal female. The term "der" refers to a chromosome "derived" from a translocation, or trading of pieces of chromosome between members of different homologous pairs. In this case, one of the chromosome 4's has lost a bit of its longer (q) arm and gained a bit of the q arm of chromosome number 8. The q35.1 refers to the band on chromosome 4 where the break occured, and q24.1 refers to the site of the break on chromosome 8. Both of these locations are near the end of the longer arm of these chromosomes. Note the result is an individual with three copies of a little bit of chromosome 8 and missing a little bit of the end of chromosome 4, a sort of fragmentary trisomy 8 and monosomy 4. Here is a graphic of the situation from the Lab of Hygiene: Notice that the chromosomes in both examples above have two complete chromosome 8's plus an extra copy of the "bottom" end of 8 on one chromsome 4. They are missing one copy of the corresponding bottom end of chromsome 4. These karyotypes are from the Wisconsin State Laboratory of Hygiene. They are intended for use in teaching to help students study human chromosomes. Copyright for these images remains with the State Laboratory of Hygiene, apply to them for permission for any other use than non-profit teaching. Each karyotype is available in one of three forms: The original unmodified smear. These may have extra material, and often have some chromosomes crossed, which makes them less useful for a class exercise in which students cut apart and arrange the individual chromosomes. A copy of the original, with extraneous materials removed, crossed chromosomes separated, and all chromosomes separated slightly to faciliate cutting apart of the chromosomes in a printed copy. This form is intended for student use in an introductory biology class. A "key", with the chromosomes arranged in standard order. To transfer the image to your computer, click on the appropriate image name, and save it to your hard disk. ZooWeb Number Original image Modified image Key ZWK99016 ZWK99016o.jpeg ZWK99016.jpeg ZWK99016k.jpeg ZWK99018 ZWK99018o.jpeg ZWK99018.jpeg ZWK99018k.jpeg For technical information on the methodology by which these smears were created click here. Karyotype_home Do you have suggestions for this page? Please contact one of the participants or email Larry Phelps (lphelps@uwc.edu) © 1998 The Board of Regents of the University of Wisconsin System. Click here to email comments regarding BioWeb or its links.