2014 methods of research into human genetics výukový materiál ge 02 - 56 tvůrce: mgr. Šárka...
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2014
METHODS OF RESEARCH INTO HUMAN GENETICS
Výukový materiál GE 02 - 56
Tvůrce: Mgr. Šárka Vopěnková
Tvůrce anglické verze: ThMgr. Ing. Jiří Foller
Projekt: S anglickým jazykem do dalších předmětů
Registrační číslo: CZ.1.07/1.1.36/03.0005
Tento projekt je spolufinancován ESF a SR ČR
human genetics differs from genetics of plants, fungi, animals and bacteria:
moral a ethic reasons human has in life a very small number of
descendants phenotype is in a very big measure influenced by the
external environment (social conditions) - polygenic features
generation period of a person is very long geneticist can observe maximally only 4 generations human genome is very complex
RESEARCH METHODS
specific observational methods:
1. research into family trees – genealogic method
2. research into twins – gemellological method
3. methods of population genetics
4. research into karyotypes
5. biochemical and molecular-genetic methods
RESEARCH METHODS
research into family trees – genealogic method : based on arrangement of family trees generation period of human = 20 – 25 let >
maximally observed 4 generations by monogenic features can be detected: feature conditioned by a dominant / recessive
allele feature is on autosome / gonosome
RESEARCH METHODS
result of research: determination of probability of
occurrence of the disease by the descendants
principal method by the diagnosis of hereditary diseases
used international symbols > e.g.. proband
RESEARCH METHODS
research into twins: a) twins originate from only one egg fertilized
by one sperm 100 % accordance of genome monozygotic twins MZ identical sex b) twins originate by fertilization of two eggs
by two sperms 50% accordance of genome dizygotic twins DZ identical or different sex
RESEARCH METHODS
monozygotic twins: MZ phenotype variations are consequence of the
non-hereditary component of variability by means of the phenotype accordance and
differences by MZ and DZ twins can be determined the mass of influence of hereditary and non-hereditary component of variability
disease with a high heritability > hereditary disease, can be predicted
disease with a high heritability > better curable
RESEARCH METHODS
research into karyotypes: cytogenetic research of chromosomes in the nucleus 23 pairs of chromosomes 220 pairs of autosomes + 1 pair of
gonosomes according to Denver nomenclature > in 7
groups A to G in agreement with their size and placing of centromeres
RESEARCH METHODS
biochemical and molecular-genetic many diseases caused by mutations defect alleles are mostly recessive ill people are also recessive heterozygotes > autosomal recessive heredity these diseases are caused by mutations of
structural genes = molecular diseases e.g.: phenylketonuria, galactosemia a
albinism
RESEARCH METHODS
handicapped child from its birth up to 15 years of age - special diet
organized a wide recapture of new born babies on the base of a simple biochemical examination
RESEARCH METHODS
DNA diagnostics: molecular-genetic method used in prenatal diagnostics e.g. Sickle-cell anaemia - disease: stricken only homozygotes ( SS) foe
defect allele S they have got erythrocytes of sickle
shape
GENETIC PREVENTION AND COUNSELLING
a big research project HGP deals with mapping of human genome started in 1990 by 2000 -2003 read the sequence of
human genome human has got 30 000 genes 98,5 % genes have a non-coding
sequence
RESEARCH METHODS
genetic counselling: an important part of preventive medicine medicine genetics department – hospitals: specification of diagnosis determination of risk of disabled children in
a high-risk family interruption essential principle of genetic counselling: guarantee of free (both) parents´ decision !!!
RESEARCH METHODS
eugenics: science struggling for improvement of biological
and mental quality of human population most effective reduction possibility of birth disabled
humans most effective reduction possibility of transmission
indisposed alleles into following generations hardly solvable contradiction: frequency of defect alleles in the populations
increases thanks to medicine (individuals with serious hereditary diseases are saved)
RESEARCH METHODS
Internationally given symbols, from which are created genealogical tables (family trees).
FILL IN THE SCHEMA
WORKSHEET
CHALUPOVÁ-KARLOVSKÁ, Vlastimila. Obecná biologie: středoškolská učebnice : evoluce, biologie buňky, genetika : s 558 řešenými testovými otázkami. 2., opr. vyd. Olomouc: Nakladatelství Olomouc, 2010, 206 s. ISBN 978-80-7182-282-0
SOURCES