...Cathy J. Wedeen; David A. Weisblat ABSTRACT ht-en protein, an annelid homolog of the Drosophila engrailed protein, is expressed during both early development and neurogenesis in embryos of the leech, Helobdella triserialis . In Helobdella as in Drosophila , early expression is in segmentally...

... determined the lengths and compositions of the mitotic cell cycles of identifiable cells in early embryos of the leech, Helobdella triserialis , and have analysed how the cell cycles change during the first seven stages of development. The relatively short cell cycles of the early blastomeres comprise...