|Budget Amount *help
¥210,860,000 (Direct Cost: ¥162,200,000、Indirect Cost: ¥48,660,000)
Fiscal Year 2013: ¥35,620,000 (Direct Cost: ¥27,400,000、Indirect Cost: ¥8,220,000)
Fiscal Year 2012: ¥50,180,000 (Direct Cost: ¥38,600,000、Indirect Cost: ¥11,580,000)
Fiscal Year 2011: ¥43,680,000 (Direct Cost: ¥33,600,000、Indirect Cost: ¥10,080,000)
Fiscal Year 2010: ¥41,730,000 (Direct Cost: ¥32,100,000、Indirect Cost: ¥9,630,000)
Fiscal Year 2009: ¥39,650,000 (Direct Cost: ¥30,500,000、Indirect Cost: ¥9,150,000)
Ascidians (Protochordates) are hermaphrodities, which release sperm and eggs almost simultaneously. Several species, including Ciona intestinalis, show self-incompatibility to avoid self-fertilization. We revealed that three pairs of egg-side ligands on the vitelline-coat (v-Themis-A, -B, and -B2) and cognate sperm-side receptors (s-Themis-A, -B, and -B2) are responsible for self/non-self recognition (allorecognition) during fertilization in C. intestinalis by genetic analyses, proteomic analyses, and genome-editing techniques. We also found that when C. intestinalis spermatozoon binds to the vitelline coat of a self-egg, Ca2+ influx into sperm takes place, resulting in the detachment of sperm from the vitelline coat. Since s-Themis-B/B2 contain a cation channel domain in their C-terminal regions, s-Themis-B/B2 may play a key role in self-recognition during fertilization of the ascidian C. intestinalis.