Centromere orientation of quadrivalents of heterozygous translocations and an autoploid of Gossypium hirsutum L. [Cotton]

• Published in: Genetics (Austin) Vol. 105; no. 3; pp. 723 - 731
• Main Authors: Endrizzi, J. E, Ray, D. T, Gathman, A. C
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Genetics Soc America 01-11-1983; Genetics Society of America
• Subjects: Biological and medical sciences; Cytogenetics; Fundamental and applied biological sciences. Psychology; Genetics of eukaryotes. Biological and molecular evolution; Gossypium hirsutum; Investigations; Vegetals and fungi; Malvaceae; Chromosomal aberration; Vegetals; Dicotyledones; Angiospermae; Chromosome association; Cytogenetics; Spatial orientation; Spermatophyta; Gossypium hirsutum; Chromosome translocation
• ISSN: 0016-6731; 1943-2631; 1943-2631
• DOI: 10.1093/genetics/105.3.723

Cytological observations of quadrivalents of heterozygous translocations in Gossypium hirsutum L. demonstrate that, in addition to alternate-1 and alternate-2 orientations, a third alternate orientation (alternate-3), which occurs as a three-dimensional, V-type configuration, can be identified.-Two additional types of disjunctions, the centromere orientations of which are rotational modifications of either adjacent or alternate configurations, were also observed in quadrivalents of a translocation heterozygote. These two types are rare, and both appear in the form of the Roman numeral X . The X and the alternate-3 types also occur in quadrivalents of an autoploid of G. hirsutum.-The two X types, along with adjacent-1, adjacent-2, alternate-1 and alternate-2 orientations, represent the six possible types of planar 2 x 2 random orientation of the four centromeres of a quadrivalent. Including the three-dimensional alternate-3 type, there are seven types of orientation.