Cytogenetic study of foetal colon mouse tumour-AKATOL-1-71-cultivated in vitro

Abstract

Presented are G-band data of the chromosomes of the tumour cell line CTC. This line was set up of an adenocarcinoma originating from a malignized embryonic colon graft in an isogenic BALB/c mouse. Non-random numerical and structural karyological changes following a determined pattern are related to neoplastic transformation after syngeneic transplantation of embryonic gut. The presumed detailed origin of three chromosome markers (M) is described in detail. M1 includes definite segments of chromosome 9 and 11. The segments are extended and have a clearly detailed band pattern that is due to prosomization. A palindromic band pattern is present in M1. Each half of this pattern originates from chromosomes 9 and 11 respectively. M2 shows deleted subcentromeric heterochromatin and is present constantly in the cells. M3 presents an inverted segment. A highly selective advantage of the cells carrying chromosome markers is demonstrated by their increase in number together with appearance of cells with double markers. The monosomic state of autosomes is correlated with respective marker formation. “Compensation” of autosomal nullisomy by markers may indicate preservation of some normal gene functions in rearranged chromosome segments. Notable is the tolerance to gonosomal monosomy and nullisomy. A specific type of markers appear as normal chromosomes with minute satellite-like structures attached to centromeres.