TY - JOUR T1 - A Silk-Expressed Pectin Methylesterase Confers Cross-Incompatibility Between Wild and Domesticated Strains of <em>Zea mays</em> JF - bioRxiv DO - 10.1101/529032 SP - 529032 AU - Yongxian Lu AU - Samuel A. Hokin AU - Jerry L. Kermicle AU - Mathew M. S. Evans Y1 - 2019/01/01 UR - http://biorxiv.org/content/early/2019/01/23/529032.abstract N2 - Despite being members of the same species, some strains of wild teosinte maintain themselves as a distinct breeding population by blocking fertilization by pollen from neighboring maize plants. These teosinte strains may be in the process of evolving into a separate species, since reproductive barriers that block gene flow are critical components in speciation. This trait is conferred by the Teosinte crossing barrier1-s (Tcb1-s) haplotype, making Tcb1 a speciation gene candidate. Tcb1-s contains a female gene that blocks non-self-type pollen and a male function that enables self-type pollen to overcome that block. The Tcb1-female gene encodes a Pectin Methylesterase, implying that modification of the pollen cell wall by the pistil is a key mechanism by which these teosinte females reject foreign (but closely related) pollen.One sentence summary The Tcb1-female gene encodes a Pectin Methylesterase that in teosinte silks prevents fertilization by maize pollen. ER -