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Mount Usu / Sarobetsu post-mined peatland
From left: Crater basin in 1986 and 2006. Cottongrass / Daylily
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Developmental biologythe study of the process by which animals and plants grow and develop, including regeneration, asexual reproduction, metamorphosis and the growth and differentiation of stem cellsGrowth and developmentGrowth (成長)irreversible change in mass |
Developmentirreversible change in state
embryogenesis |
Homeobox (ホメオボックス)DNA sequence, ≈ 180 base pairs regulating development and differentiation in the early stages of embryonic developmentGehring, Walter Jakob (1939-2014), Drosophila genetics and development cell determination in the embryo 1983 Gehring et al.: discovered homeobox |
Testis and sperm (精巣・精子)Sperm or spermatozoon (pl. –a) (精子)The morphology is different at species level. Sperms, mostly consisting of nucleus, contain least nutrients but have high mobility.![]() Fig. 32. Diagram of primitive metazoan spermatozoon (Franzen 1956). A: acrosome, H: head piece, M: mitochondrial body, PP: principal piece, MP: middle piece, T: tail section, EP: end piece, C: centriole, N: nucleus. [Sperms of Gymnosperms: Ginkgo biloba and Cycas revoluta] Egg (卵)Organization of egg cytoplams (卵細胞質)
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![]() Fig. 1. The four stages of egg maturation at which fertilization occurs in the animal kingdom. (Dalcq 1952) Lampbrush chromosome (ランプブラシ染色体)
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Species | G | GL | M | F | X | Fr | Ga | Gla | Total N | SO4 |
Arbacia lixula | + | + | + | + | ||||||
Echinus esculentus | + | |||||||||
Paracentrotus lividus | 4.6 | 3.8 | 24.3 | 0.8 | 4.7 | 20.9 | ||||
Strongylocentrotus droebachiensis | + | + | 25.0 | |||||||
S. purpuratus | 25 | 5.7 | 23 | |||||||
Sphaerechinus grarrularis | + | + | + | |||||||
Heliocidaris crassispina | + | |||||||||
Echinarachnius parma | + | |||||||||
Hemicentrotus pulcherrimus | + | |||||||||
Pseudocentrotus depressus | + | |||||||||
Echinocardium cordatum | 32.7 | 4.1 | 20.5 | |||||||
Brissopsis lyrifera | 8.1 | |||||||||
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Rana temporaria | ? | 12.7 | 3.5 | 7.1 | ? | 8.9 | 9.5 | 8.1 | ||
R. esculenta | + | + | + | ? | 9.3 | |||||
R. japonica | 28.0 | ? | 14.0 | 8.8 | ||||||
R. clamitans | ? | ? | ? | + | + | |||||
Discoglossus pictus | + | + | + | 1.7 | 16.5 | 10.0 | ||||
Bufo bufo | + | + | 10.4 | 20-40 | 7.6 | |||||
B. vulgaris formosus | 30.0 | ? | 20.0 | 8.4 | ||||||
Axolotl | + | + | + | 8.3 | ||||||
Triturus cristatus | 12.2 | 1.3 | 6.2 | 20.3 | 10.0 |
Theories on fertilization
1. Fertilizin theory (Lillie FR) - negative |
Table. O2-consumption of unfertilized and fertilized eggs
Species Stage of mat. (O2 uptake of division fertilized egg)/ at the time of (O2 uptake of fertili1ization unfertilized egg) Nereis succinea 1.3 N. limbata Germinal vesicle 1.35 Mactra laterialis 1.8 Urechis caupo 1.2 Cumingia tellinoides 0.45 Chaetopterus variopedatun 0.53 Marthasteriaa glacialis 1.0 Saxostrea commercialis Metaphase of 1st mat. 1.0 Sabellaria alveolata Division 1.1 Asterias glacialis 1.0 Ciona intestinalis 1.5 Phallusia mamillata 2.0 Rana platyrrhina 1.0 Bufo bufo Metaphase of 2nd mat. 1.0 Fundulus heteroclitus Division 1.0 Oryzias latipes 1.0 Fucus vesiculosus 1.9 Strongylocentrotua purpuratue 3.7 Psammechinus miliaris 3.6 Paracentrotus lividus 4.7 Arbacia punculata 4.5 Dendraster excentricus 3.0 Table. Fertilizability of Asterias eggs at various pH values HCl NaOH Concentration N/ N/ N/ N/ N/ Normal N/ N/ N/ N/ N/ in sea water 500 1000 2000 4000 104 sea 104 4000 2000 1000 500 water Cleaved egg % 0 2.5 8 22.5 45 53 84 92.5 88.5 89 0 |
Preparation________Eggs reaching blastula stage (%) |
Table. Nucleic acid content in nuclei during gametogenesis and cleavage in Chaetopterus
Stage Amount of DNA Condition of nucleus 1st polar body 127 ± 3 2n Sperinatozoid 61 ± 1 1n Cleavage, interphase 210 ± 9 2n-4n Cleavage, prophase 263 ± 10 4n Cleavage, telophase 124 ± 3 2n Asymmetric property (非対称性)1928 Spearman
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Development of gonad (生殖腺発達)1. Origin of primordial germ cell (gamete) (始原生殖細胞の起源)![]() Fig. Diagrams showing the displacement of the germinal cytoplasm during the early development of Bufo regularis. 2. sex differentiation (性分化) |
Pre-embryo (初期胚)= early embryo or nascent embryo![]() Fig. Diagrammatic comparison of blastulae (胞胚) of an echinoderm (a), a frog (b), a bony fish (c) and a bird (d). |
![]() Fig. A, B, development of an embryo with animal pole material graft placed in the grey crescent. A, during gastrulation; B, after neurulation. nt, neural tissue, ntt, non-neural tissue, C, D, E, development of an embryo with grey crescent graft at ventral margin. In C embryo shows two neural plates and dorsal lips, one induced, the other normal, D, E show two extreme types of embryo which are produced by these grafts, after neurulation. ![]() Fig. Segmentation and gastrulation in sea urchin. a) fertilized egg, b) 2 blastomere stage, c) 4 blastomere stage, d) 8 blastomere stage, e) 32 blastomere stage, f) blastula (appearance from above), g) blastula (longitudinal section), h) arising of first mesenchyme cells, i) gastrula occurrence. Bld-blastoderm: 1.a.g. first abdominal gap, 1.m.c. first mesenchyme cells. |
![]() Table. Chemical composition of sea urchin embryo (% wet weight) Substance Unfertilized Blastula Pluteus egg (12 hrs) Water 77.3 77.3 78.8 Dry substances 22.7 22.7 21.2 Protein nitrogen 10.7 10.2 9.7 Total carbohydrates 5.43 5.46 3.4 Glycogen 5.13 4.8 traces Fat 4.82 4.43 3.69 Ash 0.34 2.07 3.56 Table. Chemical composition of the egg and embryo of a frog (mg) Substance Egg Hatched tadpole Total nitrogen 162 159 Extractable nitrogen 40 42.8 (N of active protoplasm) Nonprotein nitrogen 4 5.0 (in nucleic acid?) Total carbohydrates 104 58 Glycogen 73.2 31 Table. Chemical composition of the eggs and later stages of development in three species of dog fish (g) Species Egg Young Scyllium canicula (oviparous) Total weight 1.3 2.7 Organic substances 0.61 0.48 Water 0.68 2.15 Mustellus vulgaris (ovoviviparous) Total weight 3.9 60.6 Organic substances 1.9 8.9 Water 1.9 49.8 Mustellus laevis (viviparous) Total weight 5.5 189.0 Organic substances 2.8 32.0 Water 2.6 152.0 mammal (哺乳類) |
1920-30 Spemann: completed the fate map a few years before
discovered organizer, by using hair loop, glass needle, pipette, etc. Organizer (形成体)= dorsal lip1) neural induction (神経誘導) – mesoderm, endoderm 2) organization center of embryo
neural induction Analysis for nature of induction (誘導特性解析)Technicalgrafting in vivo (A, B) → tissue (organ) culture system in vitro (C, D)![]() Figure 165. Four methods of exposing gastrula ectoderm to induction (diagrammatic). A, Transplantation of part of dorsal lip (stippled) into the ventral marginal zone, where it invaginates and forms a secondary archenteron. B, Transplantation of part of dorsal lip (stippled) into the blastocoele through a slit at the animal pole. Graft is eventually pressed against the ventral ectoderm. C, "Sandwich experiment": inductor (such as a centrifuged tissue homogenate) placed between two pieces of presumptive gastrula ventral ectoderm. D, Cultivation of a piece of presumptive ventral ectoderm of a gastrula in a watch glass filled with fluid containing inducing substance in solution. The reacting ectoderm is held between two layers of supporting material (silk) to prevent it from curling. |
![]() Fig. Cell-transfer experiment |
Renal system (腎臓系)developed from nephrotome, showing the relationship between ontogeny and phylogeny![]() pvc: posterior vena cave, bc: blood corpuscles, md: mesonephric (Wolfflan) duct, ga: gonad anlage, pp: presumed path of primordial germ cells to gonad anlage
gonad (♂/♀) (mesodermal) ┅┅┅ different origin |
Metaphros (kidney, 腎臓)mesodermal epithelium, mesodermal mesenchyme
Pattern formation (パターン形成)1) limb field and limb area1910 Harrison: Salamander tail bud
a) destroyed 1/2 limb bud → normal limb AP-axis: neural tube closure stage / DB-axis: tail but stage Proximal-distal: forming limb (need re-consideration) 2) limb bud – polarityA-P / D-V, somatic layer mesoderm, epidermis epithelium 3) mesodermal-ectodermal interaction |
Immunity (免疫): the state or quality of being resistant to a particular infectious disease or pathogen Table 17. Properties of non-IgM immunoglobulins of lower vertebrates. Species Class Intact Light Heavy CHO(%) Desig- Formula nation Lung fish Dipnoi 120000 22000 38000 N.D. IgN L2υ2 Bullfrog Amphibian (150000) 22000 53000 2.0 IgG ? L2γ(?)2 Marine toad Amphibian 160000 22500 53000 4.2 IgG ? L2γ(?)2 Xenopus Amphibian N.D. 22000 53000 N.D. IgG ? L2γ(?)2 26700 64500 Turtle Reptile 180000 22500 67500 IgG(Y) L2γ(Y)2 120000 22500 38000 0.9 IgN L2υ2 Sleeply Reptile 151000 22400 51000 N.D. IgG ? L2γ(?)2 lizard Duck Avian 178000 22400 68000 5.0 IgG(Y) L2γ(Y)2 118000 23000 35000 0.6 IgN L2υ2 Chicken Avian 174000 22500 67500 2.2(HEX) IgG(Y) L2γ(Y)2 N.D. N.D. N.D. N.D. IgA (L2α2) Echidna Monotreme 150000 22500 49000 2.0(HEX) IgG L2γ2 mammal |
Cell-mediated immunity (cellular immunity)Ab: overlays on cell surface – Ag-receptor
Humoral immune response: plasma cell → Ig circulation Genetic basis of cellular immune responseAccept Reject 1) isograft (= autograft), isogenic O 2) allograft O 3) AA × BB (P) Transplant P → F1 O → AB (F1) F1 → P O* 4) → AA, AB, BB F2 → F1 O *: reject the substances that have not present in itself |
Morphogenesis (形態発生)____seed germination____↑____↓ ____↑____formation and growth of stem and root ← ____↑____↓ senescence and abscission_________↑ ____↑____↓ bud dormancy →→→→→→→→→→→ ____↑____formation of flower ____↑____↓ senescence and abscission ____↑____fruit set →→→→→→→→ seed formation ____↑____↓_________________________↓ ____↑____growth and riping of fruit______ ↓ ____←←←←←←←←←←←←←← seed dormancy |
![]() Polarity (極性)
young: shoot apical meristem (root as well as stem) |
[ hormones ]
1. Auxin (オーキシン)Natural auxins = endogenous, indole acetic acid (IAA, インドール酢酸)Synthetic auxins: Ex. 2, 4-dichlorophenoxyacetic acid (2, 4-D), 2-methoxy-3, 6-dichlorobenzoic acid (dicamba) Synthesisyoung developing leavesterminal buds, growing axillary buds coleoptile tips Functionbind receptor protein in plasma membranetransport into cell activate ATPase in plasma membrane H+ ion extrusion acidify cell wall break hemicellulose-pectin bonds cellulose microfibrils slide apart cell enlarges Changes in RNA metabolism induced by auxinTable. Requirement of nucleoplasimic factor for enhanced RNA synthesis by IAA (Unit = 3H-UMP incorporated (c.p.m))Incubation system____________Unit
Complete___________________336 Table. Simulation of RNA synthesis by IAA and acceptor protein in vivo
Incubation system_β, γ32P-ATP incorporated_3H-UMP incorporated
Complete_______________________60______________6.3 Table. Comparison of RNA polymerase activity by incubation of plasma membrane in 0.1 μM 2,4-dichlorophenoxyacetic acid, indoleacetic acid, or 3,5-dichlorophenoxyacetic acid. ________[3H]-UMP incorporated (pmol/30 min/mg protein)
RNA polymearase____________88 PM, plasma membrane fraction Table. Enhancement of RNA polymerase activity by incubation of plasma membranes in 2,4-dichlorophenoxyacetic acid. Numeral = [3H]-UMP incorporated (pmol/30 min/mg protein)
RNA polymerase____________________________________ 72 PM, plasma membrane fraction |
Table. Effect of α-amanitin on enhancement of RNA polymerase by auxin-related factor.
RNA polymeraase__________________160 * α-amanitin acts as the inhibitor of mRNA synthesis. Each assay contained 2 μg of α-amanitin PLASMA CYTOPLASM NUCLEAR NUCLEUS MEMBRANE MEMBRANE Auxin | | | | -----→ | | ---→ Factor -→ | |--→ Factor + RNA polymerase | | | | ↓ | | | | Modified RNA polymerase | | | | ↓ | | | | Altered genome transcriptionA hypothesis in relation to the synthesis of nucleic acids operated by auxin. 2. Gibberellin (ジベレリン)immature seed embryo, young leaves, and roots (tissue localization) → phloem (transport)α-amylase formation induced by gibberellin![]() (left) α-amylase as % of total cell free protein synthesis. (right) Rate of α-amylase synthesis in vivo (U per 120 min) 3. Cytokinin (CK, サイトカイニン)Root apex (synthesis) → upward in xylem (transport)4. Abscisic acid (アブシジン酸)opposes action of gibberellin and auxinSynthesischloroplants - breakdown product of carotenoidsFunctiondormancy maintenance - high levels in dormant seeds and buds5. Ethylene (エチレン)Synthesis______________________________|← hemicellurosemethionine + ATP → SAM1 → ACC2 → etylene → PG3 ______________________________|→ galactose 1: S-adenosyl methionine, 2: amino cyclo propane, 3: polygalacturonase 6. Florigen (フロリゲン)Hormonal control at hormone levelAuxin-induced ethylene production - regulation of ethylene biosynthesis -
RA + RB = RAB ← additive response (R: response, AB: hormones) |
Somatic division or somatic cell division (体細胞分裂)1953 Pelc & Howard
G1 (gap1) → S (synthesis) → G2 (gap2) → M (mitosis) prophase → metaphase → anaphase → telophase Meiotic division |
1. Phytochrome (ファイトクローム) 1959 Butler WL et al.: isolated and identified from seedlings
Pr ↔ Pfr
Light treatment_____________germination (%) |
1968 Harris H
Ⓧ + ◎ + UV irradiation → Amoclae F hoclies Dry weight 5-8 2.5-4 Protein 2-5 1.5-2 ↓ RNA (mg) 1 0.4 Total carbohydrate 0.5 0.4 = Cellulose 0 0.1 Mucopolysaccharide 0 0.08 DNA 36 30 de novo: Ex. temporal changes in the synthesis patterns of actin (structural protein)
the most of energy during the emergence process is from protei. carbonhyborates are used least |
1972 Firtel RA
3H-DNA → thermal denaturation for single strand → sharing force, ca 400 nucleotides → remnant, return to double strand (= repeated sequence) → hydroxyappite column % of genome Estimated present as RNA number of genes transcripts expressed
Growth 30.2 (%) 8600
Aggregation 27.4 7800
Pseudo-plasmodium 34.2 10000
Culmination 35.6 11000
All stage 56.0 11000
Growth + Culmination 49.0
Growth + (Growth + Culmination) = 65.8: common genes present Key enzyme (キーエンザイム)UDP-galactose (polysaccharide) transferase: spore-specific substancesenzymes related to carbohydrate synthesis (cf. PSV: prespore vacuole) - absent in the stalk Ex. Blastocladiella emersonii (水生菌), Acetabularia mediterraneanuclear-cytoplasm interaction after the nuclear transfer Higher plants (高等植物)seed: analogy of animal embryoEx. α-amylase / β-amylase de novo: gene = active → m-RNA → protein (α-amylase) |
Double fertilization and division pattern![]() Fig. Life cycle of Angiospermae (Engler’s Syllabus 1964) ![]() Fig. Embryo development in Daucus carota. Longitudinal sections. The lower end of embryo in each drawing is the end directed toward micropyle. A-C, stages in development of linear four-celled embryo. D, E, two common variations in eight-celled embryos: difference in division of cell a of the four-celled embryo. F-I, older embryos varying in cell arrangement. J, embryo differentiated into main body and suspensor. Initial organization of tissue regions is present in J. Relation of parts of certain embryos to cells of the four-celled embryo (C) is indicated by the letters a-d. (Borthwick 1931). |
![]() Fig. Embryo development in Lactuca sativa (lettuce). Longitudinal sections. Lower end of embryo in each drawing is the end directed toward micropyle. A, zygote in division. B-G, embryos in successive stages of development, showing establishment of several horizontal tiers of cells. In G, cell h later gives rise to all of the suspensor cells, and the tiers above h develop into the main body of embryo. H-M, further development stages. |
embryo: gibberellin synthesis after immersion → active α-amylase synthesis → auxin → differentiationα-amylase (α-アミラーゼ)EC 3.2.1.1hydrolyses alpha bonds of large, α-linked polysaccharides, e.g., starch and glycogen, yielding short chains, dextrins and maltose |
[ seed dromancy ]
1978 Kreibich, Ulrich & Sabatini
Ribophorin in pea epicotyl Free Membrane --------------- --------------- M Sp Lp Total M Sp Lp Total Total Control 480 90 570 BA 441 103 544 GA 454 126 580 IAA 258 323 581 NAA 294 272 566
Total amount is constant - (possibility) free-bound induced by hormone
Heme = globrin, Hemine |
Elongation factor (伸長因子)1972 Tome et al.: Pea ribosomes: poly(U)-14C-phenyl alanine2 days 4 6 No addition 816 382 168 2 days 8080 ↔ 6580 4 ↓ ↓ 6 1953 ↔ 1800
S-100: sup of 105 g → translation |
Shoot apex (茎頂)Relationships between stem and root (茎と根の関係)1950 Skoog: Tobacco pith
IAA 0.002 ppm → root
_____________Callus___Roots___Leaves
1) embryoid (胚様体) |
1965 Vasil & Hildebrandt
tobacco pith cells → culture single cell → can form both bud and root 1965 Chen & Gaglston: Pelargonium pith collecting from pith → callus
medium: auxin, kinetin + agar → to liquid: differentiate root, stem and leaf 1971 Nagata & Takebe (長田・建部): Tobacco mesophyll protoplast → mature plant/embryoid → callus mass |
Defoliation (落葉)C2H4: promoting cellulase in the abscission layer (or zone)
Lamina senescence____Abscission layer(zone) |
Defoliation process (落葉過程)
cell differentiation ┌ plant hormones Flower shedding (落花)Fruit shedding (落果) |
ABC model![]() Fig. ABC model of flower development guided by three groups of homeotic genes. |