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From embryo to senescence with DEB theory for metab org

This article discusses the DEB theory for metabolism, covering topics such as embryo development, aging, energy budgets, growth, and reproduction. It explores the life stages of organisms and the interactions between different processes throughout their life cycles.

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From embryo to senescence with DEB theory for metab org

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  1. From embryo to senescencewith DEB theory for metab org Bas Kooijman Dept theoretical biology Vrije Universiteit Amsterdam Bas@bio.vu.nl http://www.bio.vu.nl/thb/ Melbourne, 2012/08/07

  2. From embryo to senescencewith DEB theory for metab org Bas Kooijman Dept theoretical biology Vrije Universiteit Amsterdam Bas@bio.vu.nl http://www.bio.vu.nl/thb/ • Contents: • intro • surface/volume • selection • embryo development • ageing Melbourne, 2012/08/07

  3. Energy Budgets • Basic processes • Feeding • Digestion • Storing • Growth • Maturation • Maintenance • Reproduction • Product formation • Aging • All processes interact during the life cycle Life stages embryo juvenile adult • Life history events • zero: • start of development • birth: • start of feeding • start of acceleration • metamorphosis: • end of acceleration • puberty: • end of maturation • start of reproduction

  4. Some DEB pillars • life as coupled chemical transformations • life cycle perspective of individual as primary target • energy & mass & time balances • stoichiometric constraints via Synthesizing Units • surface area/ volume relationships • spatial structure & transport • syntrophy (basis for symbioses) • homeostasis • intensive/extensive parameters: scaling • evolutionary perspective

  5. defecation feeding food faeces assimilation reserve somatic maintenance maturity maintenance  1- maturation reproduction growth maturity offspring structure Standard DEB scheme 2b 1 food type, 1 reserve, 1 structure, isomorph time: searching & handling feeding  surface area weak & strong homeostasis κ-rule for allocation to soma maintenance has priority somatic maint  structure maturity maint  maturity stage transition: maturation embryo: no feeding, reprod juvenile: no reproduction adult: no maturation maternal effect: reserve density at birth equals that of mother initially: zero structure, maturity

  6. DEB theory is axiomatic, based on mechanisms not meant to glue empirical models Since many empirical models turn out to be special cases of DEB theory the data behind these models support DEB theory This makes DEB theory very well tested against data Empirical special cases of DEB 11.1

  7. Von Bert growth rate -1, d ultimate length, mm Growth at constant food length, mm time, d Von Bertalanffy growth curve:

  8. volume, m3 volume, m3 Bacillus  = 0.2 Collins & Richmond 1962 time, min volume, m3 volume, m3 Escherichia  = 0.28 Kubitschek 1990 Streptococcus  = 0.6 Mitchison 1961 time, min time, min Mixtures of V0 & V1 morphs hyphal length, mm Fusarium  = 0 Trinci 1990 time, h

  9. Dynamic mixtures of V0- & V1-morphs Respiration: assim + maint + growth Assim, maint  mass Growth in diam  time at constant food V0-morph V1-morph

  10. 33 33 33 33 33 16 16 16 16 16 0.5 cm/yr 0.5 cm/yr 0.5 cm/yr 0.5 cm/yr 0.5 cm/yr 5 5 5 5 5 2 2 2 2 2 Dynamic mixtures of V0- & V1-morphs Respiration mixture  mass1/2 isomorph  mass3/4 Celleporella 15 cm/yr White et al 2011 Am. Nat., 178: 746-754

  11. 33 16 0.5 cm/yr 5 2 Dynamic mixtures of V0- & V1-morphs Respiration mixture  mass1/2 isomorph  mass3/4 Celleporella 33, 24 cm/yr White et al 2011 Am. Nat., 178: 746-754

  12. Selection affects par values Gallus gallus Red jungle fowl Indian River Broiler White leghorn

  13. Respiration ontogeny in birds ml O2 d-1 ml CO2 d-1 precocial Gallus domesticus Data: Romijn & Lokhorst 1951 altricial Troglodytes aëdon Data: Kendeigh 1940 age, d age, d • Observations: just prior to hatching • respiration shows a plateau in precocial, not in altricial birds • pore size and frequency in egg shell is such that O2 flux has constant resistance • Conclusion: ontogeny is constrained by diffusion limitation in precocial birds (Rahn et al 1990) • DEB theory: reserve dynamics controls ontogeny (same pattern in species without shells) • Minimization of water loss causes observed constant flux resistance

  14. Embryonic development Zonneveld & Kooijman 1993 Bul. Math. Biol.55: 609-635 Crocodylus johnstoni, Data: Whitehead 1987 embryo yolk O2 consumption, ml/h weight, g time, d time, d

  15. Kooijman 2012 J. Math. Biol. subm Twinning: separation of cells Twinning: separation of cells Twinning: separation of cells Kooijman 2009 J. Math. Biol. 58: 377--394 Parameter estimates from add_my_pet 2012/06/17, egg development only Maternal effect: reserve density at birth = reserve density of mother

  16. Acceleration of development Embryo: isomorphic v constant Early juvenile: V1-morphic v, {pAm} increase with length Late juvenile/adult: isomorphic v, {pAm} constant Found in: bivalves, gastropods, copepods, amphipods, decapods, collembolas, echinoderms, lancelets, tunas, flatfish, anchovy, Danio, caecilians, marsupials length time since birth

  17. Anchovy Engraulis encrasicolus embryo 0.16 cm 0.22 cm length, cm 0.4 cm 0.9 cm time, d 1.2 cm >4 cm Pecquerie 2008 PhD thesis VU A’dam

  18. Stage transitions at maturity thresholds Danio rerio 28.5°C Augustine et al 2011 Comp. Biochem. Physiol. A 159 :275–283

  19. Stage transitions at maturity thresholds < birth : isomorph birth-metamorphosis: V1-morph > metamorphosis : isomorph Danio rerio 28.5°C Data: Lauwrence et al 2008 caloric restriction Data: Augustine Augustine et al 2011 Comp. Biochem. Physiol. A 159 :275–283

  20. Acceleration 10log spec maturity at birth 10log yolkiness 10log acceleration 10log acceleration coelenterata lophotrochozoa ecdysozoa invert deuterostomata ectotherm vertebrata endotherm vertebrata

  21. Acceleration of development acceleration development no yes Casey Muller indirect Crinia georgiana Pseudophryne bibronii Nicky Mitchell direct Crinia nimbus Geocrinia vitellina

  22. Crinia georgiana max dry weight 500 mg metam hatch birth 1 metam birth ¾ Dry mass, mg ½  hatch ¼ O2 nmol/h age, d 0 1 ¾ ½  ¼ 0 Acceleration of development Mueller et al 2012, Comp. Biochem. Physiol. A 163: 103-110 12 °C age, d Pseudophryne bibronii metam max dry weight 200 mg metam birth hatch Dry mass, mg hatch birth O2 nmol/h age, d age, d

  23. Free radicals  Aging • Aging results from damage by Reactive Oxygen Species (ROS) Gerschman 1954 • link with DEB model via dioxygen consumption & metabolic activity • Aging is binary in unicellulars, and gradual in multicellulars • age-affected cells no longer divide • Typical aging only occurs in multicellulars with irreversible cell differentiation • that have post-mitotic tissues • Induction of damage inducing compounds  dioxygen consumption • contribution from assimilation is not included • because of more local occurrence in organism • Empirical evidence points to acceleration of aging • Damage inducing compounds generate • damage inducing compounds • damage compounds; hazard rate  density of damage compounds • Some chemical compounds (e.g. RNS) and -radiation can stimulate aging

  24. Ageing metabolism O2 ROS damage inducing compounds mitochondrional DNA damage compounds proteins effect on hazard endotherms continuous • DEB module • Weibull (1951) & • Gompertz (1825) model • are special cases • based on mechanisms • links with energetics

  25. Aging: ectotherms & feeding survival prob body length, cm • ad libitum • restricted 100-600 d time, d time, d Poecilia reticulata Data: Comfort, 1963

  26. Aging: endotherms & feeding feeding level 1 body weight, g embryo weight, g 0.75 0.44 time, d time, d 0.44 survival probability • Life span • hardly depends on food in ecotherms • decreases for increasing food in endotherms 0.75 1 time, d Data on Mus musculus: Weindruch et al 1986, MacDowell et al 1927 Van Leeuwen et al 2002 Biogerontology3: 373-381

  27. Aging: sex differentiation survival prob body length, mm time, d time, d Differences in aging between sexes are caused by differences in energy investment ratio g Data on Daphnia magna: MacArthur & Baillie 1929

  28. Aging in adult insects survival based on observed reproduction No growth Weibull Model =3 surviving number # of eggs/beetle, d-1 initial random mort surviving number age after eclosion, d age after eclosion, d age after eclosion, d Data: Ernsting & Isaaks, 1991 Data: Rose 1984 High food, 20/10 °C 0.63 a-2 High food, 10 °C 0.547 a-2 Low food, 20/10 °C 0.374 a-2 Notiophilus biguttatus Drosophila melanogaster

  29. General Weibull fits DEB • Both models are fitted to the same data • They fit equally well and have both 4 parameters • Contrary to the Weibull model the DEB model • is based on tested assumptions • has links with energetics via hW and hG. Data from Elandt-Johnson & Johnson 1980 for white USA males in the period 1969-1971

  30. Ageing among species Right whale slope 1/3, 1/5 Ricklefs & Finch 1995 • Conclusion for life span • hardly depends on max body size of ectotherms • increases with length in endotherms

  31. DEB tele course 2013 http://www.bio.vu.nl/thb/deb/ Free of financial costs; Some 108 or 216 h effort investment Program for 2013: Feb/Mar general theory (5w) April symposium at NIOZ-Texel (NL) (8 + 3 d) Target audience: PhD students We encourage participation in groups who organize local meetings weekly Software package DEBtool for Octave/ Matlab freely downloadable Slides of this presentation are downloadable from http://www.bio.vu.nl/thb/users/bas/lectures/ Cambridge Univ Press 2009 Audience: thank you for your attention

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