Karyotype of the Syrian Hamster2

Abstract

As a preliminary to studies on malignancy and transformation in vitro by polyoma virus, karyotypic comparisons were made between representative metaphases obtained from inbred Syrian hamster strains CB, MHA, and LSH and the noninbred stock LAKEVIEW. A karyotype of the CB strain was prepared from bone marrow and tissue-cultured embryonic cells and is presented as a standard. Of the 22 chromosome pairs, 8 could readily be identified individually. Between strains, a minor variation in chromosome #1 was noted. In addition, an anomalous sex chromosome constitution was found in hamsters obtained from noninbred stock source LENZIE. Different animals from the LENZIE source revealed 2 apparent forms of the Y chromosome, one a long telocentric and the other a medium-sized metacentric. The latter form of the Y was characteristic of the CB inbred strain and also of the other 3 hamster stocks studied. Recently published interpretations of the Y chromosome of the Syrian hamster (Mesocricetus auratus) are compared with this CB karyotype.