Transgenic lines containing stably integrated transgenes expressing an N-terminus fusion of 3FLAG::GFP to XND-1 showed identical expression patterns to that of immunostaining [Expr13418]; GFP was discernible only in the PGCs during embryonic development, expression persisted exclusively in the germline nuclei throughout larval development, and adult expression was observed in the mitotic zone through the late pachytene region with an autosomal bias (Wagner et al., 2010). XND-1 protein abruptly disappears from the late pachytene region and remains absent in mature oocytes and sperm. No somatic expression was observed with the transgenes or by immunostaining, confirming our prior conclusion from genetic studies that
xnd-1 function appears limited to the germ line (Wagner et al., 2010).