#Otx spider 62 code#

a, antennae plp, palpae peris, peristomium prost, prostomium am, antennal muscle 1.pp, first pair of parapodia 2.pp, second pair of parapodia atc, anterior pair of tentacular cirri ptc, posterior pair of tentacular cirri I–IV, segments 1–4.

#Otx spider 62 code#

Color code in (H–J): Yellow, anterior oblique muscles Blue, posterior oblique muscles orange, “cirral” and “parapodial” muscles background colors depicting segmental identities as in. Color code in (D, F): Red, cerebral ganglion axons Pink, Circum-esophageal connective axons innervating the anterior tentacular cirri and the esophageal nervous system Brown, Axons of the first chaetigerous and following segments. Z-projection (G), 3D-reconstruction of confocal sections (H, I) and schematics (J) of rhodamine–phalloidin stained animals. Frame in (E) marks approximately the region magnified in (C). (D, F) Schematics of animals in (C, E) highlighting the main axonal fibers. (C, E) Reconstructions of confocal stacks of acetylated α-tubulin-immunostained animals visualizing the axonal scaffold and ciliary bands. (A) Seven days old (B) 5 weeks old (C–J) 5 days old Platynereis worms. Relative position (A, B), innervation (C–F) and musculature (G–J) of head appendages and anterior segments before (A, C–J) and after metamorphosis (B). 2001 Damen 2002b Hughes and Kaufman 2002b Prud'homme et al. 1998 Telford and Thomas 1998 Telford 2000 Arendt et al. 1996 Rogers and Kaufman 1996 Damen et al. Light gray in (B): developing parapodial appendages Dark gray, mouth opening Yellow, neuroectoderm. An1, first antennal An2, second antennal Ch, cheliceral Ic, intercalary L1, first leg L2, second leg Md, mandibulary Mx, maxillary Pp, pedipalpal perist, peristomium prost., prostomium ps, parasegments pyg, pygidium I–VI, Platynereis larval segments. Segment abbreviations represent extant chelicerate, crustacean and insect segments having evolved from a common ancestral segment. Schematic summary correlating the posterior (orthodenticle/otx) and anterior expression borders of gbx/unplugged, hox1/labial, hox4/deformed and lox5/fushi-tarazu to the position of parasegment and segment boundaries marked by engrailed expression in the neuroectodermal regions of the hypothetical ancestral arthropod (A) and the annelid Platynereis (B). Our data thus support the view that an ancestral ground pattern of segmental identities existed in the trunk of the last common protostome ancestor that was lost or modified in protostomes lacking overt segmentation. This molecular segmental topography matches the segmental pattern of otx, gbx, and Hox gene expression in arthropods. This and the subsequent three chaetigerous larval segments harbor the anterior expression boundary of gbx, hox1, hox4, and lox5 genes, respectively. The first segment is a 'cryptic' segment that lacks chaetae and parapodia. We find that Pdu-otx defines a brain region anterior to the first discernable segmental entity that is delineated by a stripe of engrailed-expressing cells. To elucidate the evolution of segmentation and, ultimately, to align segments across remote phyla, we undertook a refined expression analysis to precisely register the expression of conserved regionalization genes with morphological boundaries and segmental units in the marine annelid Platynereis dumerilii. SUMMARY Annelids and arthropods, despite their distinct classification as Lophotrochozoa and Ecdysozoa, present a morphologically similar, segmented body plan.