This was first reported by A. Marshak and S. Marshak (1955) and was later
confirmed by other researchers (see Studitsky, 1981).
image
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Figure 2–26. (A) Phase-contrast photograph of axolot bilavent XIII entire in Ambistoma mexicanum (After Callan, 1966). c — centromer; re — right end; s — sphere; sl — stiff loops. (B) Diagrams illustrated what happens when part of a lampbrush chromosome is stretched (After Callan, 1963). (a) unstretched; (b) stretched within the elastic limit; (c) stretched beyond the elastic limit — one chromosome is broken, and a pair of lateral loops span the break.
Both the assumption of the disc invariability in number and their situation
in the polythene chromosomes (Painter, 1933) and correlation with the