2014 METHODS OF RESEARCH INTO HUMAN GENETICS Výukový materiál GE 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/ 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 read the sequence of human genome  human has got 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 SOURCES