Spontaneous Inversion Heterozygotes in <i>Aloe barbadensis</i> Mill.

Synapsis and recombination in inversion heterozygotes.

Inversion heterozygotes are expected to suffer from reduced fertility and a high incidence of chromosomally unbalanced gametes due to recombination within the inverted region. Non-homologous synapsis of the inverted regions can prevent recombination there and diminish the deleterious effects of inversion heterozygosity. The choice between non-homologous and homologous synapsis depends on the si...

Spontaneous rotational inversion in Phycomyces.

The filamentary fungus Phycomyces blakesleeanus undergoes a series of remarkable transitions during aerial growth. During what is known as the stage IV growth phase, the fungus extends while rotating in a counterclockwise manner when viewed from above (stage IVa) and then, while continuing to grow, spontaneously reverses to a clockwise rotation (stage IVb). This phase lasts for 24-48 h and is s...

A Cytogenetic Study of Crossing over in Inversion Heterozygotes of Drosophila Melanogaster.

HE recombinant off spring of Drosophila melanogaster females having free X T chromosomnls heterozygous for a long inversion are limited to even multiple crossover types. But from inversion heterozygotes in which the two X chromosomes are attached at their centromeric ends (= tandem metacentric compound X chromosome), single crossovers are frequently recovered. The synaptic configurations of the...

The nature of linkage variation with age in inversion heterozygotes of drosophila melanogaster.

* This investigation was supported in part by a research grant from the National Institute of Health, U. S. Public Health Service. From the Department of Zoology and Entomology and the Department of Botany and Plant Pathology (No. 519), Ohio State University. 1 Beadle, G. W., Chem. Revs., 37, 15-96 (1945). 2 Irwin, M. R., Adv'. Genetics, 1, 133-159 (1947). * Fox, A. S., Genetics, 34, 647-664 (1...

The distribution of x-ray induced crossovers from Curly inversion heterozygotes of drosophila melanogaster females.