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Planar structures dramatically increase the surface‐area‐to‐volume ratio, which is critically important for multicellular organisms. In this study, we utilize naturally occurring phenotypic variation among three Sansivieria species (Asperagaceae) to investigate leaf margin expression patterns that are associated with mediolateral and adaxial/abaxial development. We identified differentially expressed genes (DEGs) between center and margin leaf tissues in two planar‐leaf species Sansevieria subspicata and Sansevieria trifasciata and compared these with expression patterns within the cylindrically leaved Sansevieria cylindrica. Two YABBY family genes, homologs of FILAMENTOUS FLOWER and DROOPING LEAF, are overexpressed in the center leaf tissue in the planar‐leaf species and in the tissue of the cylindrical leaves. As mesophyll structure does not indicate adaxial versus abaxial differentiation, increased leaf thickness results in more water‐storage tissue and enhances resistance to aridity. This suggests that the cylindrical‐leaf in S. cylindrica is analogous to the central leaf tissue in the planar‐leaf species. Furthermore, the congruence of the expression patterns of these YABBY genes in Sansevieria with expression patterns found in other unifacial monocot species suggests that patterns of parallel evolution may be the result of similar solutions derived from a limited developmental toolbox. [ABSTRACT FROM AUTHOR]

Summary: Mitochondrial recombination in yeast is well recognized, yet the underlying genetic mechanisms are not well understood. Recent progress has suggested that mobile introns in mitochondrial genomes (mitogenomes) can facilitate the recombination of their corresponding intron‐containing genes through a mechanism known as intron homing. As many mitochondrial genes lack introns, there is a critical need to determine the extent of recombination and underlying mechanism of intron‐lacking genes. This study leverages yeast mitogenomes to address these questions. In Saccharomyces cerevisiae, the 3′‐end sequences of at least three intron‐lacking mitochondrial genes exhibit elevated nucleotide diversity and recombination hotspots. Each of these 3′‐end sequences is immediately adjacent to or even fused as overlapping genes with a stand‐alone endonuclease. Our findings suggest that SAEs are responsible for recombination and elevated diversity of adjacent intron‐lacking genes. SAEs were also evident to drive recombination of intron‐lacking genes in Lachancea kluyveri, a yeast species that diverged from S. cerevisiae more than 100 million years ago. These results suggest SAEs as a common driver in recombination of intron‐lacking genes during mitogenome evolution. We postulate that the linkage between intron‐lacking gene and its adjacent endonuclease gene is the result of co‐evolution. [ABSTRACT FROM AUTHOR]