C8545 Developmental Biology Lesson 4 Vertebrate Organogenesis: Ectodermal Derivatives Jan Hejátko Laboratory of Molecular Plant Physiology, Department of Functional Genomics and Proteomics, and Functional Genomics and Proteomics of Plants CEITEC Masaryk University, Brno, Czech Republic hejatko@sci.muni.cz, www.ceitec.eu Outline of Lesson 4 Organogenesis in Vertebrates: Ectodermal Derivatives  Early development of mammals  oogenesis and blastula formation  placental tissue differentiation  extraembryonic tissue formation  use of embryonal cells in mammalian transgenosis  Differentiation of neural tissue  mechanisms of neural tissue specification  signaling in the spinal cord development  spatial-specific differentiation of neural crest derivatives  stratification of neural tube  Development of brain and its derivatives  brain vesicles formation and development  eye development  cranial ganglia and sensory organ epithelia  Integument Outline of Lesson 4 Organogenesis in Vertebrates: Ectodermal Derivatives  Early development of mammals  oogenesis and blastula formation Uhnízdění (nidace, implantace) Kompaktizace Kavitace Vejcovod Oogenesis control by pituitary hormones Zygotic transcription initiates Imprinting morula Cell Adhesive Molecules (CAMs) Periclinal cell divisions Formation of the embryo proper Tvorba vlastního embrya Placenta formation Tvorba placenty Wikipedia Polární trofoblast Epiblast (embryoblast) Hypoblast Stěnový trofoblast Blastocysta (nikoliv blastula!) Blastocyst (not blastula!) Outline of Lesson 4 Organogenesis in Vertebrates: Ectodermal Derivatives  Early development of mammals  oogenesis and blastula formation  placental tissue differentiation Polární trofektoderm Stěnový trofektoderm Buňky vnitřní buněčné masy Dutina blastocysty Děložní stěna (endometrium) Parietální (nástěnný) endoderm Viscerální (vnitřní) endoderm Zona pelucida lysed via antipodal trophoblast protease secreetion BMP2 and BMP4 secretion and cell death Parietální endoderm Proamniová dutina Embryonální epiblast Viscerální endoderm Dutina blastocysty Trofektoderm Klk Polární trofoblast Vnitřní buněčná masa Hypoblast (primitivní endoderm) Cytotrofoblast Antipodální trofoblast Amniová dutina Dutina blastocystu Syncitiotrofoblast Embryonální epiblast Embryonální hypoblast Cytotrofoblast Kapilára endometria Zárodečný terčík Cytotrofoblast Dutina blastocystu Primitivní endoderm Syncitiotrofoblast There’s very early cell fate specification during mammals embryogenesis at the stage of two-celled embryo! Outline of Lesson 4 Organogenesis in Vertebrates: Ectodermal Derivatives  Early development of mammals  oogenesis and blastula formation  placental tissue differentiation  extraembryonic tissue formation Processes of the primitive streak and Hensen’s node formation are conserved between chicken and human embryos and the first genes involved are being identified (e.g. HEX, CERBERUS, ARCADIA, etc.]. However, the head organizing centre seems to be specific and neceessary for human embryos. Amniová dutina Žloutkový váček Somatic mesoderm Splanchnic mesoderm Zárodečný stvol Somatic mesoderm Splanchnic mesoderm Šíje Isthmus (equivalent to splanchnic mesoderm of allantois in birds) Tělní stopka, budoucí pupek Body stalk, the future umbilicus gonadotropins, steroids How many cells are necessary for the embryo proper formation? Outline of Lesson 4 Organogenesis in Vertebrates: Ectodermal Derivatives  Early development of mammals  oogenesis and blastula formation  placental tissue differentiation  extraembryonic tissue formation  use of embryonal cells in mammals transgenosis Outline of Lesson 4 Organogenesis in Vertebrates: Ectodermal Derivatives  Early development of mammals  oogenesis and blastula formation  placental tissue differentiation  extraembryonic tissue formation  use of embryonal cells in mammals transgenosis  Differentiation of neural tissue  mechanisms of neural tissue specification Ušní plakoda Myotomy De Robertis and Kuroda, Annu Rev Cell Dev Biol (2004) XOLLOID RELATED zinc metalloprotease CHORDIN Preventing nuclear translocation De Robertis and Kuroda, Annu Rev Cell Dev Biol (2004) FIBROBLAST GROWTH FACTOR INSULINLIKE GROWTH FACTOR DNA binding multiple protein interaction HEPATOCYTE GROWTH FACTOR EPIDERMAL GROWTH FACTOR Outline of Lesson 4 Organogenesis in Vertebrates: Ectodermal Derivatives  Early development of mammals  oogenesis and blastula formation  placental tissue differentiation  extraembryonic tissue formation  use of embryonal cells in mammals transgenosis  Differentiation of neural tissue  mechanisms of neural tissue specification  signaling in the spinal cord development late gastrula early-to-late neurula Covergent extension Konvergentní extenze Driven by notochord elongation Homologues of the Drosophila’s HOM genes are involved in the anteroposterior axis formation Dno neurální trubice Valeria Marigo Neural crest formation Commisural neurons, dorsal-type interneurons Motor neurons, ventraltype interneurons BMPs SHH, CHORDIN Outline of Lesson 4 Organogenesis in Vertebrates: Ectodermal Derivatives  Early development of mammals  oogenesis and blastula formation  placental tissue differentiation  extraembryonic tissue formation  use of embryonal cells in mammals transgenosis  Differentiation of neural tissue  mechanisms of neural tissue specification  signaling in the spinal cord development  spatial-specific differentiation of neural crest derivatives Melanocyty Ganglia zadního (dorzálního) kořene Sympatická ganglia (uzliny) Autonomní ganglia Nadledviny Viscerální ganglia Přední (ventrální) kořen Ventral root ? Ciliární ganglion Thoraic region (somite 1-7) Hrudní oblast Midbody region (somite 18-24) Střední oblast těla Sacral region (somite > 28) Křížová oblast Střevní ganglia Dřeň nadledvin Outline of Lesson 4 Organogenesis in Vertebrates: Ectodermal Derivatives  Early development of mammals  oogenesis and blastula formation  placental tissue differentiation  extraembryonic tissue formation  use of embryonal cells in mammals transgenosis  Differentiation of neural tissue  mechanisms of neural tissue specification  signaling in the spinal cord development  spatial-specific differentiation of neural crest derivatives  stratification of neural tube Plášťová zóna Okrajová (marginální) zónaEpendymální zóna Měkká plena mozková Cerebrospinal fluid production into the lumen neurons and glia neurites spinalcord,hindbrain Mozeček Mozek midbrain,forebrain Inhibition of apoptosis and presence of NGF Activation of RTK Outline of Lesson 4 Organogenesis in Vertebrates: Ectodermal Derivatives  Early development of mammals  oogenesis and blastula formation  placental tissue differentiation  extraembryonic tissue formation  use of embryonal cells in mammals transgenosis  Differentiation of neural tissue  mechanisms of neural tissue specification  signaling in the spinal cord development  spatial-specific differentiation of neural crest derivatives  stratification of neural tube  Development of brain and its derivatives  brain vesicles formation and development 4-somites stage 7-somites stage 11-somites stage 14-somites stage Zadní mozek Střední mozek Přední mozek Optický váček (brain vesicles) Lateral view of three-days old chick embryo Koncový (velký) mozek Mezimozek Hypofýza Zadní mozek (vlastní) Medulla oblongata/Prodloužená mícha Rhombomery Mícha Zadní mozek Střední mozek Přední mozek Cerebellum Pons area Mozeček Varolův most Isthmus Optický váček PAX6 PAX2, 5 HOX FGF8 Retinoic acid Expression of genes specifying anteroposterior axis, preventing cell migration ENGRAILED Specification of diencephalon/mesencephalon interface Formation of cartilagous precursors of vertebrae Segmental brain development, characterized by differential stratification of neural tube, nuclei and tracts anatomy. Ventrikuly Sluchové váčky The remnants of the neural tube origin Koncový (velký) mozek Mezimozek Střední mozek Zadní mozek Prodloužená mícha Optický váček Čelistní oblouk Optický váček Sluchový váček Changes in motility, cell division and apoptosis results into further segmental brain differentiation and vesicles formation acquiring of identity of individual vesicles, their wiring and final sculpting of the brain Outline of Lesson 4 Organogenesis in Vertebrates: Ectodermal Derivatives  Early development of mammals  oogenesis and blastula formation  placental tissue differentiation  extraembryonic tissue formation  use of embryonal cells in mammals transgenosis  Differentiation of neural tissue  mechanisms of neural tissue specification  signaling in the spinal cord development  spatial-specific differentiation of neural crest derivatives  stratification of neural tube  Development of brain and its derivatives  brain vesicles formation and development  eye development Optical vesicle Optický váček Stalk of optical vesicle Stopka optického váčku Brain Mozek Lens placode Čočková plakoda Pigmented retina Pigmentovaná sítnice Neural retina – photoreceptors (rods, cons) Neurální sítnice Diencephalon Mezimozek Optical cup Ectopic overexpression of EYLESS results into ectopic eye formation in Drosophilla and mouse PAX6 is able to complement eyless mutation Ectopic eye in the head region Ectopic eye below the wing Ectopic eye on the antena DECAPENTAPLEGIC (BMP orthologue) HEDGEHOG identity determined by EYLESS Outline of Lesson 4 Organogenesis in Vertebrates: Ectodermal Derivatives  Early development of mammals  oogenesis and blastula formation  placental tissue differentiation  extraembryonic tissue formation  use of embryonal cells in mammals transgenosis  Differentiation of neural tissue  mechanisms of neural tissue specification  signaling in the spinal cord development  spatial-specific differentiation of neural crest derivatives  stratification of neural tube  Development of brain and its derivatives  brain vesicles formation and development  eye development  cranial ganglia and sensory organ epithelia Čichový Optic Zrakový Trigeminal Trojklanný Facial Lícní Auditory Rovnovážně sluchový Glossopharyngeal Jazykohltanový Vagus Bloudivý nasal placode nasal epithelium otic placode inner ear I. Čichový (nervus olfactorius) II.Zrakový (n. olfactorius) III. Okulomotorický (n. oculomotoricus) IV. Kladkový (n. trochlearis) V. Trojklanný (n. trigeminus) VII.Lícní (n. facialis) VI. Odtažný (n. abducens) VIII. Rovnovážně sluchový (n. statoacusticus) IX. Jazykohltanový (n. glossopharyngicus) X. Bloudivý (n. vagus) XI. Přídatný (n. accesoriccus) XII. Podjazykový (n. hypoglossus) Outline of Lesson 4 Organogenesis in Vertebrates: Ectodermal Derivatives  Early development of mammals  oogenesis and blastula formation  placental tissue differentiation  extraembryonic tissue formation  use of embryonal cells in mammals transgenosis  Differentiation of neural tissue  mechanisms of neural tissue specification  signaling in the spinal cord development  spatial-specific differentiation of neural crest derivatives  stratification of neural tube  Development of brain and its derivatives  brain vesicles formation and development  eye development  cranial ganglia and sensory organ epithelia  Integument Zrohovatělé buňky Dermis (filling with keratin, apoptosis) Key Concepts  The first zygote division in the mammal development is highly asymmetric  Mammals developed placenta as a terrestrial life adaptation that is different from terrestrial adaptations of birds and amphibians and allows intrauteral embryo development.  There is intense tissue communication during neural tube development allowing its differentiation in both anteroposterior and dorsoventral axis via formation of morphogen gradient.  Multipoptent neural crest undergo complex targeted cell movements that allows their spatial-specific differentiation.  Eye development is highly conserved.  Both neural cord and eye development employ common mechanism of morphogenic gradient formation: BMP/HGG