Tea for Two

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Tea for Two

• Symbiosis
• BacteriaAnimal
• PlantAnimal
• AnimalAnimal

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Background Definitions

• Symbiosis a close, prolonged association
  between two or more different organisms of
  different species that may, but does not
  necessarily, benefit each member
• From International Symbiosis Society the
  acquisition of one organism by another unlike
  organism and through their subsequent long term
  intimacy develop novel metabolism and structures
  (more related to symbiosis with microorganisms)
• A major focus in biology becoming a discipline
  unto itself (some universities teach upper level
  Biology Classes specifically on this topic)

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Additional Information

• Symbiosis is an intimate association between 2
  different organisms and occurs with regularity
  across all species, all ecosystems
• Larger organism (host) smaller (symbiont) e.g.
  bacterial colonization (symbiont) of the skin
  digestive tract of humans (host)

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Benefits of Symbiosis

• Depends on the type of symbiosis
• e.g. bacteriaanimal in general, a stable
  environment is provided to the symbiont by the
  host symbiont (bacteria) may obtain nutrients
  from the host (at no sacrifice/detriment to the
  host) symbionts in turn can protect the host
  by making it more difficult for colonization by
  pathogenic bacteria some symbionts supply host
  with nutrients that the host cannot synthesize
  themselves nor obtain from their food

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Types of Symbiosis3-6 categories (?)

• Parasitism ( / -) a form of symbiosis in
  which the population of one species benefits at
  the expense of the population of another species
  e.g. influenza virus in a human
• Commensalism ( / 0) (at table together)
  a symbiotic relationship in which one species
  benefits and the other is not affected e.g.
  barnacles on jaws of whales
• Mutualism ( / ) a form of symbiosis where
  both organisms benefit e.g. lichen symbiotic
  relationship between an alga and a fungus alga
  provides food and the fungus provides water and
  nutrients

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Background Definitions cont

• Competition neither species benefits (-/-)
  competition between members of a species is the
  driving force of evolution and natural selection
  competition for resources e.g food, water,
  territory etc. results in the ultimate survival
  and dominance of the various of the species best
  suited for survival a limited amount of
  resources are available, and several species may
  depend on these resources, thus each competes
  with other to gain the resources, thus several
  species less suited to compete for the resources
  may either adapt or die out competition is also
  prominent in predator-prey relationships both
  the predator and prey are competing against one
  another for survival the predator is seeking
  food, and the prey is seeking to survive

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Background Definitions cont

• Amensalism association for one is
  disadvantageous while the other is not affected
  (- / 0) usually occurs when one organism
  exudes as part of its normal metabolism a
  chemical compound detrimental to another organism
  e.g. Penicillium (bread mold) secrete penicillin
  (kills bacteria)
• Neutralism - both species are unaffected (0 /
  0) very hard to prove it exists but it has
  been used to describe situations where species do
  not interact with or affect each other but occupy
  the same ecosystem
• see http//www.101science.com/Symbiosis.htm as
  well for more info

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Types of Symbiosis - Interactions -

• Parasitism Commensalism
  Mutualism
• _____________________________________
• 0 Neutralism Commensalism
• A _____________________________________
• - Competition Ammensalism
  Parasitism
• _____________________________________
• - 0
• Organism B
• http//www.cals.ncsu.edu/course/ent591k/symbiosis.
  html supplemented

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Background Definitions cont

• Some contemporary researchers believe this
  categorization of symbiosis to be outmoded
  ambiguous suggest that symbiotic systems are
  more fluid less linear that suggested by these
  types. Furthermore, these individuals also
  suggest that primary research action currently
  focuses on the genetic basis of symbiotic
  associations that nearly all symbiotic systems
  with broad and even global significance involve
  at least one microorganism and furthermore, that
  nearly all symbioses result in a new structure,
  frequently an organ of some kind e.g.
  trophosomes, nodules, arbuscles, thalli,
  mycetomes, intestine, reef, rumen etc. From
  International Society of Symbiosis News, March,
  1998, vol 1 issue 3 p 1-3, Douglas Zook author
  see http//people.bu.edu/iss/Symbiosisdefine.htm)

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Background Definitions cont

• Ectosymbiosis the symbiont lives on the body
  surface of the host including internal surfaces
  such as the lining of the digestive tube and
  ducts of glands I.e. extracellular
• Endosymbiosis symbiont lives within the body or
  cells or another organism
• Obligate neither symbiont nor host can survive
  without the other

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E.g. Various types of Symbiotic Relationships as
seen in Insects

• Nutritional e.g. Ambrosia beetles, termite
  fungus gardens, parasol ants (also a type called
  cleaning symbiosis e.g. Nile Crocodile
  permitting Egyptian plover to feed on leeches
  attached to its gums not an insect!!)
• Shelter (aka inquilism) ant mimics, slave-maker
  ants, gall insects
• Transport (aka Phoresy) using a second organism
  for transport e.g. torsalo, scelioned wasps
• Pollination eg. nectar guides, bottle gentians,
  dung beetles and skunk cabbage, bumblebees and
  scotch broom
• Defensive e.g. ants acacias, aphid farmers

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Other terms

• Metabiosis more indirect dependency, in which
  the second organism uses something the first
  created, however after the death of the first
  e.g. hermit crabs who use gastropod shells to
  protect their body

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BacteriaAnimal Symbiosis

• Most animals plants live symbiotically with
  microorganisms
• When symbiosis is not in play or is disrupted,
  disease ensues dis-ease

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Examples of BacteriaAnimal Symbiosis

• Symbiont Host Type
  Location Function
• __________________________________________________
  _________
• Aeromonas veronii Hirudo Digestive
  Extracellular unknown
• medicinalis tract
• Vibrio fischen Euprymna Light
  Extracellular Light Production
• scolopes Organ
• Buchnera sp. Aphidoidea Nutritional
  Intracellular Digestive Tract
• Xenorthabdus Steinemema Digestive
  Intracellular Digestion of
• nematophilus nematophilus Tract
  insect host
• From University of Connecticut Department of
  Molecular and Cell Biology http//web.uconn.edu/mc
  bstaff/graf/Sym.html site dedicated to
  bacteriaanimal symbiosis

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A closer look at some examples

• Squid V. fisheri
• Newly born juvenile squid do not contain any
  symbionts (aposymbiotic)
• Light organ has modifications that aid in
  obtaining V. fisheri present in sea water
• Once light organ is colonized by V. fisheri,
  the symbionts change anatomically and stimulate
  the development of the light organ from features
  that aid in acquisition of symbionts to
  functioning as a light organ
• Light organ provides protection for nocturnal
  squid by providing illumination that camouflages
  the squid from predators swimming below it (I.e.
  against the moonlight)

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A closer look at some examples

• Rumenants and microbs
• Rumenants e.g. cattle with intestinal bacteria
  that breakdown cellulose as mammals are not able
  to catabolize the carbohydrate cellulose - 50
  of the organic carbon is tied up in cellulose
  enormous source of energy, yet vertebrate cells
  do not produce the cellulases necessary to break
  it down but various microorganisms within the
  rumenants GIT can and make byproducts available
  for the animal
• Flourishing microbial populations can provide
  50-80 of a cows daily protein requirements
  up to 80 of its energy requirements - rumen (1st
  portion of 4 part stomach) is a fermentation
  vat providing an anaerobic environment, constant
  temperature pH, this microbes good mixing
  calves begin their life as monogastrics drink
  milk which by-passes the rumen until the
  forestomachs are fully developed seeded with
  appropriate microbes

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PlantAnimal Symbiosis

• E.g. A sloth has hollow hair which allows a green
  algae to colonize with the hair, while a tropical
  alga moth lives in the fur
• Many examples of heterotrophs (and algae)
• any organism that obtains its energy from
  organic substances produced by other organisms
  unable to synthesize organic carbon-based
  compounds independently from the inorganic
  environments sources

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The Coral ReefA Very Special Example of
algaeanimal symbiosis

• The second most diverse mega-ecosystem (2nd to
  rainforests)
• A direct result of dinoflagellate ( others
  individuals) encysted within the animal tissue
• Gastro-vascular marine cnidarians existing as
  small sea anemone-like polyps, typically forming
  colonies of many individuals
• Reef-builders are called hermatypic corals found
  in tropical oceans much of the living tissue of
  this animal thinly covers a skeleton composed of
  calcium carbonate the living tissue is just a
  thin veneer measuring several millimeters in
  thickness

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The Coral ReefA Very Special Example of
algaeanimal symbiosis cont

• Coral are animals that need a brown algae i.e.
  zooanthellae (collective term for 2 groups of
  protistans I.e. the cryptonmonads
  dinoflagellates) living inside them to survive
• coral benefits by receiving their nutrients via
  algal cells photosynthesis (thus, they must be
  fairly close to surface of water for the algae to
  be exposed to sunlight) receive indirect
  assistance with deposition of their calcium
  carbonate (CaCO3) skeletons the algae in turn,
  have a shelter/home

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a closer look at some examples

• Ants and acacia e.g. of obligate mutualism
  Pseudomyrmex ants are provided shelter in the
  form of large hollow thorns feed from acacia
  nectaries and eat beltain bodies/nodules these
  stinging ants vigorously defend their host
  colony by protecting acadia from herbivores,
  lizards, snakes and other insects

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AnimalAnimal Symbiosis

• Ant birds follow army ants eating fleeing insects
  while butterflies follow the ant birds feeding on
  their droppings
• Clown fish and sea anemone commensalism clown
  fish lives among deadly tentacles of sea anemone
  where it is protected from its predators because
  of the sea anemones stinging tentacles and eats
  food left by sea anemone while protecting the sea
  anemones from anemone-eating fish (clown fish is
  protected from the stinging tentacles by a
  special mucus)

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Examples of AnimalAnimal Symbiosis

• Remora/fish and turtles attaches to side of
  other fish and turtles and eats food they drop
  commensalism
• Barnacles/whales and manatees, etc. barnacles
  attach as harmless hitchhikers some sp. are
  found only as commensal on jaws of whales and
  other species of barnacles found only as
  commensal on top of those barnacles
  commensalism
• Tapeworms/human parasitism malaria
  (Plasmodium)/humans flukes pigs humans
  hookworms/animals

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Examples of AnimalAnimal Symbiosis

• Humananimal symbiosis?
• Interdependence between species
• No sustainable agricultural system exists without
  animals
• Animals play critical roles including
• Lateral vertical transfer of nutrients
• Nutrient content and availability
• Transport for distribution
• Conversion of human-inedible resources
• Energy sparing effects
• Mental health companionship

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Examples of AnimalAnimal Symbiosis

• Humananimal connection? Humananimal bond?
• Moves beyond animals as a source of food and
  other items
• Consideration here for animal welfare, animal
  rights, legalities/legislation, engineered
  creatures, cloning, factory farms, animal-based
  research, etc.
• Specialized professions influences of this
  consideration animal psychology, molecular
  biology, veterinary specialists (e.g. animal
  welfare)

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Examples of AnimalAnimal Symbiosis

• Other influences include contemporary topics in
  animal science classes, increasing social
  awareness, consciousness understanding the
  sociological impact that animals have on people
  using this relationship (e.g. taking cats and
  dogs to nursing homes impacts the elderly
  emotionally/physiologically)

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Physiological Processes and Mechanisms

• Most major symbioses (especially of the
  bacteriaanimal type of association) have 3
  distinct features
• By their association, each result in a unique or
  novel metabolism and structure(s), both of which
  are not present prior to the symbiosis
• From International Society of Symbiosis News,
  March, 1998, vol 1 issue 3 p 1-3, Douglas Zook
  author see http//people.bu.edu/iss/Symbiosisdef
  ine.htm)

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Physiological Processes and Mechanisms

• Each are so continuously intimate from generation
  to generation that their recognition, infection
  and regulation systems would of necessity have to
  involve very selective co-evolution with perhaps
  some ancient or recurrent genetic exchange (some
  researchers e.g. Lynn Margulis contend that
  symbiosis is a major driving force behind
  evolution she claims evolution is strongly based
  on co-operation, interaction and mutual
  dependence life did not take over the globe by
  combat, but by networking the direction of a
  symbiotic interaction can change during the
  lifetime of the symbionts due to developmental
  changes as well as changes in the biotic/abiotic
  environment in which the interaction occurs)

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Physiological Processes and Mechanisms

• The process particularly of bacteriaanimal
  symbiosis involves an acquisition whether
  ancient and/or each generation, i.e. one organism
  acquires one or more different organisms, and
  there is enough of selective advantage that they
  are maintained through natural selection

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Physiological Processes and Mechanisms

• E.g. May E. Rumpho, University of Maine gene
  exchange basis of some symbiotic systems is that
  of kleptoplasty the sequestering of foreign
  plastids in what usually would be considered a
  heterotrophic host e.g. certain naked mollusk or
  sea slugs
• (a phenomenon whereby plastids from algae are
  sequestered by a host organism the algae is
  eaten normally and partially digested, leaving
  only the plastid the plastid is maintained,
  continuing to fix carbon for the hosts nutrition)

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Physiological Processes and mechanisms

• E.g. Hawaiian sepoilid squid E. scolopes marine
  luminous bacterium Vibrio fischeri engage in
  most common type of bacteriaanimal symbiosis
  I.e. extracellular, gram-negative bacteria
  animal epithelial relationship begins anew each
  generation when the host animal acquires the
  symbiont from the surrounding environment to
  establish a specific association, mechanisms have
  evolved to ensure recognition between the host
  symbiont the exclusion of other potential
  partnerships once the relationship is
  established, the bacteria induce significant
  morphological changes in the host that result in
  a transition of the light organ from a form
  associated with initiation of they symbiosis to
  one characteristic of the mature, functioning
  relationship

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Examples of Challenges when the symbiotic
relationship is disrupted

• Pseudomonas aeruginosa found on the skin of
  humans does not cause disease ( as a
  commensial) however, if the person experiences a
  sever burn to the skin, P. aeruginosa can cause
  an infection (I.e. relationship changes as then
  the once symbiont becomes a pathogen i.e.
  disease-causing organism)