Ecology

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Ecology

• Introduction to ecology

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Ecology

• The science of the study of the relationships
  between living things and their environment
• The environment could be
• Biotic other species
• Nonbiological (abiotic) physical, chemical,
  geographical, geological factors

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Applications of ecology in medicine

• Medical ecology
• Preventive medicine (hygiene)
• Social medicine
• Epidemiology
• Toxicology
• Genotoxicology deals with mutagenic effects of
  environmental factors
• Medical parasitology
• Medical microbiology
• Alergology
• Geographic medicine
• Medical geology

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Genetic and environmental background of diseases
Injuries
Cystic fibrosis
Tumor diseases
Deafness
Color blindness
Infections
Diabetes mellitus
Intoxications
Phenylketonuria
INHERITANCE ENVIRONMENT (genetic
factors) (environmental factors)
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Basic ecological terms
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Population

• A group of individuals of the same species living
  in the same area or interbreeding and sharing
  genetic information.

Population of species A
Population of species B
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Ecosystem

• Ecological community nonbiological factors
• The minimum system that includes and sustains
  life
• It must include
• An autotroph
• A decomposer
• A source of energy
• All the chemical elements required by the
  autotroph and the decomposer

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Ecosystem
Abiotic factors
Community
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Food web (trophic chain)
Secodary consumers (carnivores)
Solar energy
Primary consumers (herbivores)
Producers (green plants, algae, autotrophic
bacteria)
Decay of organic matter
Release of inorganic nutrients
Decomposers (heterotrophic bacteria, fungi)
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Energy flow within food web
Biomass of secondary consumers
Loss of energy
Loss of energy
Biomass of primary consumers
Biomass of producers
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Interspecific relations
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CommensalismOne species benefits, the other
doesn't but is not harmed.
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Interspecific relations
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Protocooperation
Example A hermit crab and the sea anemone
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Interspecific relations
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Mutualism

• Giant Clam (Tridacna squamosa)
• The mantle (soft tissue) within the shell is
  brightly coloured brown, blue and/or green. This
  is due to the microscopic algae known as
  zooxanthellae living inside the tissues which
  photosynthesise (manufacture food) from sunlight
  and the waste metabolic products of the clam.
  They are then "harvested" by the clam as
  supplementary food.

• Despite being "farmed" this way, the algae are
  assured of a safe "residence" and a continued
  supply of nutrients.

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Another example of mutualism lichens
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Bacteria in the gut
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Interspecific relations
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Antibiosis
Epicoccum nigrum and Sclerotinia sclerotiorum
Antibiosis test of bacteria
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Interspecific relations
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Parasites in humans

• Viruses
• Bacteria
• Fungi (e.g. some parasitic yeasts)
• Protozoa or Protista (e.g. Trypanosoma,
  Plasmodium, Toxoplasma)
• Flatworms (e.g. liver fluke)
• Roundworms (e.g. ascarid)
• Insects (e.g. mosquito)
• Arachnoids (e.g. tick)

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Microbiology and parasitology

• Viruses
• Bacteria
• Fungi
• Protozoa
• Flatworms
• Roundworms
• Insects
• Arachnoids

Medical microbiology
Medical parasitolgy
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Plasmodium a typical parasite transmitted by
mosquito
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Interspecific relations
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POLYMORPHISM AND VARIABILITY
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Polymorphism

• Environmental
• (induced by changes of environmental factors)
• Genetic
• (refers to differences in the DNA sequence)

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Environmental polymorphism
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Genetic polymorphism

• Occurrence of two ore more different genetically
  conditioned phenotypes in the population.
• POLYMORPHISM x MUTATION
• Frequency of rare allele is higher then 0,01
  (i.e. 1).

MUTATION
POLYMORPHISM
1
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Manifestation of genetic polymorphism

• Phenotypic polymorphism (variable genetically
  conditioned traits)
• Biochemical (immunological) polymorphism
  (differences in protein structure and molecular
  weight, in presence of different antigens or
  blood groups etc.)
• Chromosomal polymorphism
• DNA polymorphism (different DNA sequences,
  different length of certain segments)

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Manifestation of genetic polymorphism

• Phenotypic polymorphism (variable genetically
  conditioned traits)
• example Pea plant (color of flower, shape of
  seeds, height of plant etc.)

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Manifestation of genetic polymorphism

• Phenotypic polymorphism (variable genetically
  conditioned traits)
• Biochemical (immunological) polymorphism
  (differences in protein structure a molecular
  weight, in presence of different antigens,
  different blood groups etc.)
• Chromosomal polymorphism
• DNA polymorphism (different DNA sequences,
  different length of certain segments)

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Biochemical polymorphism

• Allelic forms of enzymes or isoenzymes (e.g.
  phosphoglucomutase, malatdehydrogenase, acid
  phosphatase)
• Electrophoresis of proteins

Individuals
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Immunologic polymorphism

• Histocompatibility antigens (HLA)
• Erythrocytal antigens
• ABO
• MN
• Rh
• Lutheran (Lua, Lub)
• Lewis (Lea, Leb)
• Duffy (Fya, Fyb)
• Kell (K, k)
• Xg (Xga, Xg)
• and more others

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Manifestation of genetic polymorphism

• Phenotypic polymorphism (variable genetically
  conditioned traits)
• Biochemical (immunological) polymorphism
  (differences in protein structure a molecular
  weight, in presence of different antigens, blood
  groups etc.)
• Chromosomal polymorphism
• DNA polymorphism (different DNA sequences,
  different length of certain segments)

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Chromosomal polymorphism

• Different length of p-arms of acrocentric
  chromosomes
• Different extent of heterochromatin areas

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Manifestation of genetic polymorphism

• Phenotypic polymorphism (variable genetically
  conditioned traits)
• Biochemical (immunological) polymorphism
  (differences in protein structure a molecular
  weight, in presence of different antigens, blood
  groups etc.)
• Chromosomal polymorphism
• DNA polymorphism (different DNA sequences,
  different length of certain segments)

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DNA polymorphism

• Segments of different length (frequently number
  of repeats)
• DNA-fingerprinting, RFLP etc.
• Segments of different DNA sequence
• DNA sequencing, hybridization with specific
  probes etc.

C T A C G
C T A C A
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Importance of polymorphism studies

• Phorensic genetics (paternity tests,
  identification of persons)
• Transplantation (polymorphism of
  histocompatibility antigens)
• Molecular epidemiology (identification of
  different pathogenic strains)
• importance in medical microbiology and
  parasitology (identification of sibling
  species)
• Molecular taxonomy
• studies of evolution molecular clock
• Some polymorphisms can express certain disorder
  under specific conditions (e.g. after ingestion
  of certain food or application of certain drug)
• ECOGENETICS
  PHARMACOGENETICS
• Each person has different (genetically
  conditioned) susceptibility to certain
  environmental factor or chemical compound, drug,
  physical or biological factor.

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Ecogenetically important polymorfisms in human
population I.

• Hemoglobine variants (HbS homozygotes are
  affected with sickle cell anemia, heterozygotes
  are resistant to malaria infection)
• Glucoso-6-dehydrogenase deficiency (hemolytic
  crisis after application of certain drugs or
  ingestion of beans)
• Different lactase activity (lactose intolerance
  after ingestion of milk)
• Different acetaldehyddehydrogenase (ALDH)
  activity (intolerance to ethanol increased in
  some Asiatic populations and in South American
  Indians)

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Ecogenetically important polymorphisms in human
population II.

• Alfa 1-antitrypsine (ATT) protease inhibitor,
  decreased level leads to severe inflammations of
  respiratory tract, pancreas and liver)
• Cytochrome P450-monooxygenase oxidizes
  xenobiotics including severe carcinogens and
  mutagens (a lot of isoenzyme forms with different
  inducibility had been described)
• Arylhydrocarbon hydroxylase (AHH) converts
  aromatic hydrocarbons to epoxides (most of them
  have carcinogenic effect)

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No lecture next week! (dean's day)

• Practical Parasitism
• Test in ecology (lecture) is not excluded!