ENETIC cytoplasmic male sterility in Sorghum is fundamentally an aspect of the problem of gene action and nuclear-cytoplasmic interaction. Our interest in the problem stems not from a concern with the practical use so effectively being made of the failure of certain lines to produce functional pollen but rather from a desire to know more about the basic components of this process as an example ...

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Hybrid sterility of the heterogametic sex is one of the first postzygotic reproductive barriers to evolve during speciation, yet the molecular basis of hybrid sterility is poorly understood. We show that the hybrid male sterility gene Odysseus-site homeobox (OdsH) encodes a protein that localizes to evolutionarily dynamic loci within heterochromatin and leads to their decondensation. In Drosoph...

Drosophila simulans and Drosophila mauritiana are closely related sibling species, the former cosmopolitan and the latter restricted to the small oceanic island of Mauritius. Genetic analysis of male sterility in hybrids between these species shows that at least five loci (one on each chromosome arm) are responsible for this reproductive isolation. This is the most loci that could have been det...

Postzygotic reproductive isolation is characterized by two striking empirical patterns. The first is Haldane's rule--the preferential inviability or sterility of species hybrids of the heterogametic (XY) sex. The second is the so-called large X effect--substitution of one species's X chromosome for another's has a disproportionately large effect on hybrid fitness compared to similar substitutio...

Most genetic studies of Haldane's rule, in which hybrid sterility or inviability affects the heterogametic sex preferentially, have focused on Drosophila. It therefore remains unclear to what extent the conclusions of that work apply more generally, particularly in female-heterogametic taxa such as birds and Lepidoptera. Here we present a genetic analysis of Haldane's rule in Heliconius butterf...

Transfer of Cytoplasmic Male Sterility into Rice Diversifying the existing cytoplasmic male sterility (CMS) sources of rice is indispensable for a sustainable production system of hybrid seed. Ahmadikhah et al. report that maintainer line Yosen B was converted to a CMS line (Yosen A) in three generations by markerassisted backcrossing. The recurrent parent genome content of the final CMS line w...

Known in over 150 species, cytoplasmic male sterility is encoded by aberrant mitochondrial genes that prevent pollen development. The RNA- or protein-level expression of most of the mitochondrial genes encoding cytoplasmic male sterility is altered in the presence of one or more nuclear genes called restorers of fertility that suppress the male-sterile phenotype. Cytoplasmic male sterility/rest...