In the yeast Saccharomyces cerevisiae, small chromosomes undergo meiotic reciprocal recombination (crossing over) at rates (centimorgans per kilobases) greater than those of large chromosomes, and recombination rates respond directly to changes in the total size of a chromosomal DNA molecule. This phenomenon, termed chromosome size-dependent control of meiotic reciprocal recombination, has been...

We study non-crossing frameworks in the plane for which the classical reciprocal on the dual graph is also non-crossing. We give a complete description of the self-stresses on non-crossing frameworks G whose reciprocals are non-crossing, in terms of: the types of faces (only pseudo-triangles and pseudo-quadrangles are allowed); the sign patterns in the stress on G; and a geometric condition on ...

3. The relatively stable derivatives obtained by selling fertile Fz plants. . . . . . . . . (a) Origin and behavior of amphidiploid lines. . . . . . . . . . . . . . . . . . . . . . . . . . . (b) Result of crossing amphidiploids with parental species. . . . . . . . . . . . . . . . . . . . . . . . . . . (1) Reciprocal backcrosses to rustica pzcmila. . . . . . . . . . . . . . . . . . . . . . . . ....

Meiotic reciprocal recombination (crossing over) was examined in the outermost 60-80 kb of almost all Saccharomyces cerevisiae chromosomes. These sequences included both repetitive gene-poor subtelomeric heterochromatin-like regions and their adjacent unique gene-rich euchromatin-like regions. Subtelomeric sequences underwent very little crossing over, exhibiting approximately two- to threefold...

HE X-linked white locus of Drosophila melanogaster is a complex region of Tthe chromosome which has been subdivided into a number of sites (LEWIS 1952; MACKENDRICK and PONTECORVO 1952; GREEN 1959, 1964; JUDD 1959, 1964). Heterozygotes for two mutant alleles mapping at different sites in the white region (except for compounds with the right-most site, for white-spotted) do not show complementati...

Homologous recombination is an important mechanism for the repair of double-strand breaks in DNA. One possible outcome of such repair is the reciprocal exchange or crossing over of DNA between chromosomes. Crossovers are beneficial during meiosis because, as well as generating genetic diversity, they promote proper chromosome segregation through the establishment of chiasmata. However, crossing...

Homologous recombination is an important mechanism for the repair of double-strand breaks in DNA. One possible outcome of such repair is the reciprocal exchange or crossing over of DNA between chromosomes. Crossovers are beneficial during meiosis because, as well as generating genetic diversity, they promote proper chromosome segregation through the establishment of chiasmata. However, crossing...