title: A nanos homolog in leech.
abstract: From the glossiphoniid leech Helobdella robusta, we have cloned and determined the complete coding sequence of Hro-nos, a gene homologous to the nanos gene from Drosophila melanogaster. Developmental northern blots show that Hro-nos, like nanos, is a maternal transcript that decays rapidly during early development. A polyclonal antiserum raised against the HRO-NOS protein was used in developmental western blots and for immunostaining leech embryos of different developmental stages. The HRO-NOS protein is first detectable in 2-cell embryos (4-6 hours of development) and exhibits a transient expression peaking during fourth cleavage (9-12 cells; 8-14 hours of development). The HRO-NOS protein exhibits a graded distribution along the primary embryonic axis and is partitioned unequally between the sister cells DNOPQ and DM, progeny of macromere D' at fourth cleavage: DNOPQ is the segmental ectoderm precursor cell and exhibits levels of HRO-NOS protein that are at least two-fold higher than in cell DM, the segmental mesoderm precursor cell. The observed expression pattern suggests that Hro-nos plays a role in the decision between ectodermal and mesodermal cell fates in leech.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley 94720-3200, USA.
authors.forename: M
authors.initials: M
authors.lastname: Pilon
authors.forename: D A
authors.initials: DA
authors.lastname: Weisblat
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D004331:Drosophila melanogaster / Q000235:genetics; D004625:Embryo, Nonmammalian / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect; D007150:Immunohistochemistry; D007865:Leeches / Q000196:embryology* / Q000235:genetics; D008969:Molecular Sequence Data; D010957:Plasmids; D016133:Polymerase Chain Reaction; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity
chemical_list: D017931:DNA Primers; D004268:DNA-Binding Proteins; C106187:HRO-NOS protein, Helobdella robusta; D011993:Recombinant Fusion Proteins