txid6341[Organism] - GEO DataSets

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Select item 2002772811.

Molecular profiles, sources and lineage restrictions of stem cells in an annelid regeneration model

(Submitter supplied) Regeneration of missing body parts can be observed in diverse animal phyla, but it remains unclear to which extent these capacities rely on shared or divergent principles. Research into this question requires detailed knowledge about the involved molecular and cellular principles in suitable reference models. By combining single-cell RNA sequencing and mosaic transgenesis in the marine annelid Platynereis dumerilii, we map cellular profiles and lineage restrictions during posterior regeneration. more...

Organism:: Platynereis dumerilii

Type:: Expression profiling by high throughput sequencing

Platform:: GPL34906
9 Samples

Download data: RDATA

Series

Accession:: GSE277281

ID:: 200277281

Select item 2002501872.

Annelid methylomes reveal ancestral developmental and ageing-associated epigenetic erosion across Bilateria

(Submitter supplied) Background DNA methylation in the form of 5-methylcytosine (5mC) is the most abundant base modification in animals. However, 5mC levels vary widely across taxa. Whilst vertebrate genomes are hypermethylated, in most invertebrates, 5mC concentrates on constantly and highly transcribed genes (gene body methylation; GbM) and, in some species, on transposable elements (TEs), a pattern known as ‘mosaic’. more...

Organism:: Owenia fusiformis; Capitella teleta; Dimorphilus gyrociliatus

Type:: Methylation profiling by high throughput sequencing

6 related Platforms
35 Samples

Download data: BED, CGMAP, TXT

Series

Accession:: GSE250187

ID:: 200250187

PubMed Full text in PMC Similar studies

Select item 2001968523.

Comparative transcriptomics between two potentially toxin-secreting marine annelids: Glycera alba and Hediste diversicolor

(Submitter supplied) Transcriptome profiling of whole proboscis and body wall of the marine Polychaeta Glycera alba, adults, wild population (sex undiscriminated), collected from the muddy-sandy intertidal flats at W Portugal (2020). Transcriptome profiling of glandular and muscular regions of proboscis of the marine Polychaeta Hediste diversicolor, adults, wild population (sex undiscriminated), collected from the muddy-sandy intertidal flats at W Portugal (2019).

Organism:: Hediste diversicolor; Glycera alba

Type:: Expression profiling by high throughput sequencing

Platforms:: GPL31948 GPL31947
12 Samples

Download data: FASTA, XLSX

Series

Accession:: GSE196852

ID:: 200196852

PubMed Full text in PMC Similar studies

Select item 2002252304.

Maternal patterns of inheritance alter transcript expression in eggs

(Submitter supplied) Background: Modifications to early development can lead to evolutionary diversification. The early stages of development are under maternal control, as mothers produce eggs loaded with nutrients, proteins and mRNAs that direct early embryogenesis. Maternally provided mRNAs are the only expressed genes in initial stages of development and are tightly regulated. Differences in maternal mRNA provisioning could lead to phenotypic changes in embryogenesis and ultimately evolutionary changes in development. more...

Organism:: Streblospio benedicti

Type:: Expression profiling by high throughput sequencing

Platform:: GPL33124
24 Samples

Download data: TXT

Series

Accession:: GSE225230

ID:: 200225230

PubMed Full text in PMC Similar studies

Select item 2002108145.

The ATAC epigenomic profiling of Capitella teleta development

(Submitter supplied) Capitella teleta is a model specie in marine annelids research, to gain insight into its development, we performed time-course ATAC-seq ranging from 64 cell to stage 8 larvae, to profiling the gene regulation dynamics

Organism:: Capitella teleta

Type:: Genome binding/occupancy profiling by high throughput sequencing

Platform:: GPL31133
10 Samples

Download data: NARROWPEAK, TXT

Series

Accession:: GSE210814

ID:: 200210814

PubMed Full text in PMC Similar studies

Select item 2002108136.

The adult tissue transcriptome of Owenia fusiformis

(Submitter supplied) Owenia fusiformis is an ancestral sister group to the annelids, it has a unique "head larvae" type named mitraria larvae. To identify the gene expressed in different tissues, especially the gene expressed in head region, we dissected the 5 female worms and 1 male worm to get 9 different tissues, and extracted their RNA. The sequencing were performed on BGISEQ-500 platform, and the mapping were done with Kallisto and normalization was performed with DEseq2.

Organism:: Owenia fusiformis

Type:: Expression profiling by high throughput sequencing

Platform:: GPL32556
9 Samples

Download data: FASTA, TXT

Series

Accession:: GSE210813

ID:: 200210813

PubMed Full text in PMC Similar studies

Select item 2002022837.

The developmental transcriptome and epigenome of Owenia fusiformis reveal the development and evolution of mitraria larvae [dataset2]

(Submitter supplied) Owenia fusiformis has a unique mitraria larvae form which is different to other marine spiralians. we utilize RNA-seq and ATAC-seq to profile the gene expression and chromatin accessibility dynamics to understand their development and evolution.

Organism:: Owenia fusiformis

Type:: Expression profiling by high throughput sequencing; Genome binding/occupancy profiling by high throughput sequencing

Platform:: GPL30632
11 Samples

Download data: NARROWPEAK, TXT

Series

Accession:: GSE202283

ID:: 200202283

PubMed Full text in PMC Similar studies

Select item 2001924788.

The developmental transcriptome profiling of Capitella teleta

(Submitter supplied) Capitella teleta is a model specie in marine annelids research, to gain insight into its development, we performed time-course RNA-seq ranging from 64 cell to stage 7 larvae, to profiling the gene expression dynamics

Organism:: Capitella teleta

Type:: Expression profiling by high throughput sequencing

Platform:: GPL31133
10 Samples

Download data: TXT

Series

Accession:: GSE192478

ID:: 200192478

PubMed Full text in PMC Similar studies

Select item 2002173099.

Epigenome of three deep-sea polychaete species

(Submitter supplied) We provide the genome-wide methylome surveys of three species of deep-sea polychaete worms using Oxford Nanopore data: the siboglinids Paraescarpia echinospica and Ridgeia piscesae, and the alvinellid Paralvinella palmiformis. We characterised 5mCpG methylation in order to test hypotheses about the putative role of DNA methylation in these species.

Organism:: Paraescarpia echinospica; Ridgeia piscesae; Paralvinella palmiformis

Type:: Methylation profiling by high throughput sequencing

Platforms:: GPL32825 GPL32824 GPL32823
4 Samples

Download data: BIGWIG, TXT

Series

Accession:: GSE217309

ID:: 200217309

PubMed Full text in PMC Similar studies

Select item 20021730810.

Epigenome of an adult Paralvinella palmiformis body wall

(Submitter supplied) 5mCpG methylation for Paralvinella palmiformis

Organism:: Paralvinella palmiformis

Type:: Methylation profiling by high throughput sequencing

Platform:: GPL32825
1 Sample

Download data: BIGWIG, TXT

Series

Accession:: GSE217308

ID:: 200217308

Select item 20021730711.

Epigenome of an adult Ridgeia piscesae vestimentum

(Submitter supplied) 5mCpG methylation for Ridgeia piscesae.

Organism:: Ridgeia piscesae

Type:: Methylation profiling by high throughput sequencing

Platform:: GPL32824
2 Samples

Download data: BIGWIG, TXT

Series

Accession:: GSE217307

ID:: 200217307

Select item 20021730612.

Epigenome of an adult Paraescarpia echinospica vestimentum

(Submitter supplied) 5mCpG methylation for Paraescarpia echinospica.

Organism:: Paraescarpia echinospica

Type:: Methylation profiling by high throughput sequencing

Platform:: GPL32823
1 Sample

Download data: BIGWIG, TXT

Series

Accession:: GSE217306

ID:: 200217306

Select item 20019586913.

Comparative analysis of genome-scale, base-resolution DNA methylation profiles across 580 animal species

(Submitter supplied) We mapped DNA methylation in 580 animal species (535 vertebrates, 45 invertebrates), resulting in 2443 genome-scale, base-resolution DNA methylation profiles of primary tissue samples from various organs. Reference-genome independent analysis of this comprehensive dataset defined a “genomic code” of DNA methylation, which allowed us to predict global and locus-specific DNA methylation from the DNA sequence within and across species. more...

Organism:: Mya arenaria; Loligo vulgaris; Strongylocentrotus droebachiensis; Holothuria; Ciona intestinalis; Lophius piscatorius; Hemitripterus americanus; Cyclopterus lumpus; Thunnus albacares; Testudinidae; Varanus; Gekkonidae; Boa constrictor; Struthio camelus; Sturnus vulgaris; Phoenicopteriformes; Ara; Ara ararauna; Aptenodytes patagonicus; Petauridae; Dasypodidae; Scandentia; Varecia; Saguinus; Macaca sylvanus; Papio hamadryas; Theropithecus gelada; Canis lupus familiaris; Nasua; Martes foina; Mustela putorius; Felis silvestris; Phocidae; Equus; Equus zebra; Sus scrofa; Bison bonasus; Capra; Apodemus sylvaticus; Lagostomus maximus; Myocastor coypus; Saccoglossus kowalevskii; Psittacus; Castoridae; Styela montereyensis; Ardea; Buteo; Buteo buteo; Balearica pavonina; Grus japonensis; Corvus; Bubo bubo; Carcharias taurus; Axis axis; Vicugna; Hippoglossoides elassodon; Trachemys scripta elegans; Gypaetus; Morone saxatilis; Hippoglossoides platessoides; Capromys pilorides; Petaurus breviceps; Suricata; Hemitragus; Chloris chloris; Lepas anatifera; Chamaeleonidae; Lutjanus mahogoni; Circus cyaneus; Pithecia pithecia; Patiria miniata; Geochelone; Cyclura; Apodemus flavicollis; Sciurus vulgaris; Centropomus robalito; Cyclura cornuta; Cornufer guentheri; Antidorcas; Antilope; Kobus leche; Agapornis canus; Agapornis lilianae; Agapornis taranta; Varanus gouldii; Scincidae; Sebastes atrovirens; Sebastes caurinus; Sebastes hopkinsi; Sebastes miniatus; Geoemyda spengleri; Mullus surmuletus; Pomatomus saltator; Corucia zebrata; Picus viridis; Nothobranchius furzeri; Fromia; Asio otus; Strix aluco; Trioceros jacksonii; Theloderma; Nectariniidae; Ploceus cucullatus; Spinus spinus; Ctenochaetus striatus; Urophycis tenuis; Caloenas nicobarica; Euplectes; Coracias garrulus; Pisaster giganteus; Pleurogrammus monopterygius; Glyptocephalus zachirus; Clavelina picta; Mungos mungo; Accipiter nisus; Fistularia commersonii; Cygnus cygnus; Anoplopoma fimbria; Uromastyx ocellata; Stichopus chloronotus; Trachyphonus erythrocephalus; Coris gaimard; Eumyias panayensis; Pytilia melba; Potamochoerus porcus; Ecteinascidia turbinata; Pachyuromys; Holothuria atra; Sebastes semicinctus; Podothecus accipenserinus; Falco cherrug; Pitta moluccensis; Camelus ferus; Ptilinopus pulchellus; Chiroxiphia pareola; Sphoeroides maculatus; Astrochelys yniphora; Boltenia echinata; Echinarachnius parma; Alitta succinea; Bodianus diana; Cantherhines pardalis; Cheilodipterus quinquelineatus; Tetrastes bonasia; Parapercis xanthozona; Lumpenus lampretaeformis; Pseudanthias ventralis; Xenagama wilmsi; Loweina rara; Coracias cyanogaster; Vanellus armatus; Oxycercichthys veliferus; Onuxodon fowleri; Cirrhilabrus roseafascia; Copsychus malabaricus; Hypanus americanus; Riftia pachyptila; Homarus americanus; Pisaster brevispinus; Leucoraja erinaceus; Negaprion brevirostris; Danio rerio; Esox lucius; Gadus morhua; Myzopsetta ferruginea; Chelydra serpentina; Emydidae; Graptemys; Varanus exanthematicus; Naja; Vipera ammodytes; Dromaius novaehollandiae; Columba livia; Falco peregrinus; Haliaeetus albicilla; Serinus; Phalacrocorax carbo; Macropodidae; Erinaceidae; Leontocebus fuscicollis; Saguinus mystax; Cercopithecus; Vulpes vulpes; Ursus; Ursus arctos; Procyon lotor; Meles meles; Felis catus; Tayassuidae; Cervidae; Cervus nippon; Muntiacus; Ammotragus; Bos; Boselaphus tragocamelus; Bubalus; Cricetinae; Caviidae; Hydrochoerus hydrochaeris; Heterocephalus; Macroscelidea; Macroscelides proboscideus; Dolichotis; Duttaphrynus melanostictus; Corvus corone; Strigiformes; Vicugna pacos; Yinpterochiroptera; Acinonyx; Colobus guereza; Glyptocephalus cynoglossus; Erethizon; Nyctereutes; Trachemys; Stenotomus chrysops; Zosteropidae; Strix uralensis; Hippotragus; Vidua paradisaea; Cebinae; Phascolarctos cinereus; Leiocephalus; Carollia perspicillata; Milvus milvus; Cynomys; Psammomys obesus; Sylvia atricapilla; Python regius; Pogona barbata; Aquila heliaca; Eurypygidae; Jacanidae; Lissemys punctata; Ecsenius; Agapornis; Mimus polyglottos; Canis aureus; Tiliqua scincoides; Sebastes mystinus; Sebastes paucispinis; Ariopsis felis; Abronia anzuetoi; Eudyptes chrysocome; Pomacentrus coelestis; Terrapene; Lampropeltis; Embiotoca jacksoni; Geronticus eremita; Fromia indica; Ducula bicolor; Rhinoptera bonasus; Probosciger aterrimus; Monacanthidae; Halichoeres trimaculatus; Phyllopteryx taeniolatus; Tringa totanus; Chloropsis; Tockus deckeni; Chamaeleo calyptratus; Gymnothorax moringa; Centropristis striata; Erpeton; Laemanctus; Labroides bicolor; Cuora mccordi; Amazona agilis; Histrio histrio; Zenopsis conchifer; Uraeginthus bengalus; Bathymaster signatus; Pseudobalistes fuscus; Trachemys scripta scripta; Sebastes borealis; Lutjanus quinquelineatus; Lepidopsetta polyxystra; Oxycheilinus digramma; Giraffa giraffa; Pleoticus muelleri; Ovis orientalis; Geopelia placida; Photoblepharon palpebratum; Calyptocephallela gayi; Scolopsis bilineata; Atherinomorus vaigiensis; Leptoclinus maculatus; Coris caudimacula; Gadus chalcogrammus; Doryteuthis pealeii; Crocodylia; Ophioderma panamensis; Notamacropus rufogriseus; Cirrhilabrus lineatus; Lonchura oryzivora; Tockus alboterminatus; Illex illecebrosus; Strongylocentrotus purpuratus; Branchiostoma floridae; Galeocerdo cuvier; Callorhinchus milii; Clupea harengus; Salvelinus alpinus; Xiphias gladius; Ambystoma mexicanum; Heloderma; Casuarius casuarius; Rhea americana; Anas platyrhynchos; Ciconiidae; Columbidae; Accipiter gentilis; Circus aeruginosus; Acryllium vulturinum; Gallus gallus; Perdix perdix; Phasianus colchicus; Coturnix delegorguei; Spheniscus humboldti; Pteropus; Callithrix jacchus; Saguinus oedipus; Saguinus imperator; Macaca; Colobus polykomos; Pongo; Canis lupus; Panthera leo; Panthera pardus; Puma concolor; Tapirus; Sus scrofa domesticus; Camelus dromedarius; Lama glama; Tragulus javanicus; Capreolus capreolus; Rangifer tarandus; Ovis aries; Kobus; Capricornis; Oryctolagus cuniculus; Spermophilus; Cricetus; Rattus norvegicus; Rattus rattus; Amazona; Lynx lynx; Nymphicus hollandicus; Tinca tinca; Dolichotis patagonum; Incilius alvarius; Chauna torquata; Rollulus; Capromyidae; Vipera berus; Scopus umbretta; Rupicapra rupicapra; Pythonidae; Pelecanus crispus; Cucumaria frondosa; Coccothraustes; Polychrus marmoratus; Cygnus melancoryphus; Erythrura; Phodopus campbelli; Neoniphon sammara; Eunectes; Haliaeetus leucocephalus; Cariamidae; Macaca silenus; Musophagidae; Garrulus glandarius; Leontopithecus chrysomelas; Upupa epops; Paralichthys dentatus; Nanger dama; Myoxocephalus octodecemspinosus; Tragelaphus spekii; Sebastes ovalis; Hypselecara coryphaenoides; Spatula querquedula; Equus asinus asinus; Elephas maximus indicus; Falco tinnunculus; Tetrao urogallus; Testudo kleinmanni; Hoplobatrachus tigerinus; Musophaga; Osteoglossum bicirrhosum; Ptilinopus; Athene noctua; Polypedates otilophus; Correlophus ciliatus; Rhinogobiops nicholsii; Otaria; Leucoraja ocellata; Pycnonotus barbatus; Psarisomus dalhousiae; Cynoscion regalis; Acanthurus triostegus; Alectis ciliaris; Lethrinus atkinsoni; Hippoglossina oblonga; Scophthalmus aquosus; Gallicolumba; Amandava subflava; Furcifer pardalis; Choerodon fasciatus; Coronella austriaca; Thyonella gemmata; Neurergus; Diodon hystrix; Canis lupus lycaon; Euplectes orix; Chromis punctipinnis; Haemulon flavolineatum; Semicossyphus pulcher; Dinemellia; Hemisphaeriodon; Halocynthia pyriformis; Phloeomys; Cuora mouhotii; Merops apiaster; Pseudanthias; Ambystoma andersoni; Malacochersus; Cyanoliseus patagonus; Ostorhinchus aureus; Zaprora silenus; Platax teira; Saimiriinae; Pseudomonacanthus peroni; Sebastes norvegicus; Dracaena guianensis; Aonyx cinereus; Merops bullockoides; Ammodytes hexapterus; Sufflamen chrysopterum; Cyclopsitta diophthalma; Centropyge heraldi; Parupeneus spilurus; Vermilingua; Folivora; Lethenteron camtschaticum; Callocephalon fimbriatum; Ophiopteris papillosa; Ophiothrix spiculata; Rhyticeros narcondami; Ostorhinchus rueppellii; Cheilopogon californicus; Octopus vulgaris; Lytechinus variegatus; Squalus acanthias; Mustelus canis; Cyprinus carpio; Salmo salar; Salmo trutta; Pollachius virens; Zoarces americanus; Ambystoma; Iguanidae; Tiliqua rugosa; Natrix tessellata; Crotalus; Dendrocygna viduata; Charadriidae; Ciconia ciconia; Gallus; Coturnix coturnix; Parus major; Sarcophilus; Macropus; Tupaia; Lemur; Papio; Ailurus fulgens; Mustelidae; Lutra lutra; Mustela; Panthera onca; Panthera tigris; Rhinocerotidae; Cervus elaphus; Capra aegagrus; Connochaetes; Lepus europaeus; Marmota; Acomys; Mus musculus; Hystricidae; Melopsittacus; Tamias; Magallana gigas; Molgula citrina; Botryllus schlosseri; Heleophrynidae; Dama dama; Yangochiroptera; Leontopithecus; Pelecanus; Hippotragus equinus; Ostrea edulis; Cricetomyinae; Uromastyx; Cynictis; Glis glis; Oplurus; Bothriechis schlegelii; Brachylophus; Passer domesticus; Jaculus; Sauromalus; Python molurus; Acanthosaura; Shinisaurus crocodilurus; Plegadis falcinellus; Eliomys quercinus; Corvus corax; Coliiformes; Agapornis personatus; Loriculus galgulus; Leptailurus; Lepus timidus; Astrochelys radiata; Tragelaphus angasii; Sebastes constellatus; Sebastolobus alascanus; Paracanthurus hepatus; Corvus frugilegus; Dascyllus aruanus; Coryphaenoides acrolepis; Testudo hermanni; Paracirrhites forsteri; Scyliorhinus retifer; Nardoa novaecaledoniae; Chaetodon lineolatus; Chaetodon lunula; Buteo lagopus; Batoidea; Loweina terminata; Penaeus; Caiman yacare; Cacatua alba; Paroedura picta; Rhacophorus reinwardtii; Recurvirostra avosetta; Irena puella; Bycanistes bucinator; Elops affinis; Philomachus; Zamenis longissimus; Ascidiella aspersa; Tamiops; Amblyglyphidodon leucogaster; Rhinecanthus aculeatus; Hemilepidotus jordani; Triglops scepticus; Oxylebius pictus; Tockus flavirostris; Taurotragus; Cephalopholis miniata; Aotidae; Sebastes chrysomelas; Pterocaesio marri; Notamacropus parma; Lamprotornis chalcurus; Boltenia ovifera; Rhabdamia gracilis; Chrysopelea; Pristigenys alta; Salvelinus umbla; Holothuria cinerascens; Grus paradisea; Lyrurus tetrix; Ammodytes dubius; Cryptacanthodes maculatus; Prionotus carolinus; Ostorhinchus moluccensis; Apostichopus parvimensis; Cyanoloxia brissonii; Leptoptilos crumenifer; Tockus nasutus

Type:: Methylation profiling by high throughput sequencing

580 related Platforms
3023 Samples

Download data: BED

Series

Accession:: GSE195869

ID:: 200195869

PubMed Full text in PMC Similar studies SRA Run Selector

Select item 20018412614.

The developmental transcriptome and epigenome of Owenia fusiformis reveal the development and evolution of mitraria larvae

Organism:: Owenia fusiformis

Type:: Expression profiling by high throughput sequencing; Genome binding/occupancy profiling by high throughput sequencing

Platform:: GPL30632
26 Samples

Download data: FASTA, NARROWPEAK, TXT

Series

Accession:: GSE184126

ID:: 200184126

PubMed Full text in PMC Similar studies SRA Run Selector

Select item 20014395415.

A phylogenetic approach to the recruitment of venom proteins in a marine Polychaeta

(Submitter supplied) Transcriptome profiling of whole proboscis and body wall of the marine Polychaeta Eulalia sp. (Eulalia viridis), adults, wild population (sex undiscriminated), collected from the rocky intertidal at W Portugal (2018).

Organism:: Eulalia viridis

Type:: Expression profiling by high throughput sequencing

Platform:: GPL28020
6 Samples

Download data: FASTA, XLSX

Series

Accession:: GSE143954

ID:: 200143954

PubMed Full text in PMC Similar studies SRA Run Selector

Select item 20015956416.

Resolving transcriptional states and predicting lineages in the annelid Capitella teleta using single-cell RNAseq

(Submitter supplied) Here we use a whole-organism, single-cell transcriptomic approach to map larval cell types in the annelid Capitella teleta at 24- and 48-hours post gastrulation (stages 4 and 5). We identified eight unique cell clusters (undifferentiated precursors, ectoderm, muscle, ciliary-band, gut, neurons, neurosecretory cells and protonephridia), thus helping to identify previously uncharacterized molecular signatures such as novel myogenic and neurosecretory cell markers. more...

Organism:: Capitella teleta

Type:: Expression profiling by high throughput sequencing

Platform:: GPL29252
2 Samples

Download data: MTX, TSV

Series

Accession:: GSE159564

ID:: 200159564

SRA Run Selector

Select item 20015425117.

Functional evidence that Activin/Nodal signaling is required for establishing the dorsal-ventral axis in the annelid Capitella teleta

(Submitter supplied) Transcript abundances were examined in single Capitella teleta embryos at three timepoints: 8-cell, 16-cell, and 32-cell stage.

Organism:: Capitella teleta

Type:: Expression profiling by high throughput sequencing

Platform:: GPL28854
12 Samples

Download data: CSV, TXT

Series

Accession:: GSE154251

ID:: 200154251

PubMed Full text in PMC Similar studies SRA Run Selector

Select item 20007018518.

The mid-developmental transition and the evolution of animal body plans

(Submitter supplied) This SuperSeries is composed of the SubSeries listed below.

Organism:: Danio rerio; Mnemiopsis leidyi; Nematostella vectensis; Schmidtea polychroa; Hypsibius dujardini; Platynereis dumerilii; Drosophila melanogaster; Amphimedon queenslandica; Caenorhabditis elegans; Strongylocentrotus purpuratus

Type:: Expression profiling by high throughput sequencing

10 related Platforms
1143 Samples

Download data: PDF, XLSX

Series

Accession:: GSE70185

ID:: 200070185

PubMed Full text in PMC Similar studies

Select item 20006494319.

Platynereis dumerilii high resolution developmental transcriptomic time-course

(Submitter supplied) Classical embryological studies revealed that during mid-embryogenesis vertebrates show similar morphologies. This “phylotypic stage” has recently received support from transcriptome analyses, which have also detected similar stages in nematodes and arthropods. A conserved stage in these three phyla has led us to ask if all animals pass through a universal definitive stage as a consequence of ancestral constraints on animal development. more...