AGRICULTURAL
UNIVERSITY OF ATHENS
Department of Food 
Science & Human Nutrition

Genetics

Content

1. Introduction in Genetics - Mendelian analysis:
Mendel’s analysis. Monohybrids, dihybrids and multihybrids crosses. Variations on dominance. Mendelian genetics in agriculture and humans. Pedigree analysis. Mendelian analysis and definition of probability. Product and sum rules. The χ2 test.
2. Extension of Mendelian analysis:
Multiple alleles. ABO blood group in humans. Incompatibility alleles in plants. Operational test of allelism. Lethal alleles. Gene interaction. Epistasis. Complementation test. Three or more gene interaction. Pleiotropism - Penetrance – Expressivity. Modifier genes. Genetic suppression. Position effect. Genetic anticipation. Epigenetic inheritance. Paramutation. Parental imprinting
3. Genotype and Environment:
The norm of reaction. Genotype-environment interactions. Developmental noise. Twin studies.
4. Linkage and chromosome mapping:
Chromosome recombination from independent assortment. Intrachromosomal recombination. Genetic and cytological events correlation of intrachromosomal recombination. Tetrads analysis and stage of meiosis during which crossing - over occurs. Linkage of two genes. Genes in coupling or repulsion phase. Meiotic crossover and recombination is absent in Drosophila males. Linkage of genes on the X chromosome. Estimation of recombination frequency from dihybrid crosses. Genetic distance between two genes. Maximum recombinant frequency between linked genes. Linkage map of three or more genes. Three – point testcross. Coefficient of coincidence. Coefficient of interference. Estimation of progenies proportion from linkage map. Mapping function. Sister chromatid exchanges. Intralocus recombination.
5. Cell cycle. Mitosis. Meiosis. Spermatogenesis. Oogenesis:
Cellular structure and genetic function. Diploid organisms and homologous chromosomes. Mitosis. Meiosis. Gamete formation, spermatogenesis and oogenesis. Sexual reproduction in diploid organisms. Chromosome structure in mitosis and meiosis.
6. Sex chromosomes, Sex determination, and sex-linked inheritance:
Sex chromosomes. Sex determination (C elegans, Drosophila, mammals). Mechanism of gene dose compensation. Syndrome Turner and Klinefelter. Y chromosome, SRY gene in the development of testis, Sex reversal, holandric genes. Χ chromosome, Χ inactivation, Epigenetic mechanisms. Sex-linked inheritance, recessive and dominant X-linked. Sex-influenced inheritance. Sex-limited inheritance.
7. Gene and chromosomal mutations:
Molecular basis of mutations. Types of mutations. Mutagenesis agents. Changes in chromosome structure. Deletions. Duplications. Inversions. Translocations.
8. Changes in chromosome number:
Euploidy. Monoploids. Triploids. Autotetraploids. Allopolyploids. Aneuploidy. Monosomics. Trisomics.
9. Extranuclear inheritance. Mitochondrial DNA. Mitochondrial diseases. Chloroplast DNA. Origin of mitochondria and chloroplasts.

Laboratory exercises:
Genetic problems on Mendelian genetics for the study of one or multiple genes, epistasis, genetic linkage and genetic maps, estimation of recombination frequency from genetic crosses, X-linked genes, gender-affected and gender-restricted heredity. Predicting the heredity of a trait by studying the results of experimental crosses. Support predictions with the chi-square (x2) statistical test. Predicting the offspring of a cross, for a trait with a given type of heredity. Applications in probability calculations. Experimental design to confirm the results and predictions mentioned above.

Learning results

This is a basic course that presents the fundamentals of the science of Genetics.
Its aim is to introduce students to the basic principles of Genetics, while also reporting to the theory and techniques of genetic analysis.
Lastly, the course’s aim is the understanding of the methodology of solving Genetics problems.
After successfully completing this course, students will:

  • Have acquired knowledge on the functions and interactions of genes
  • Have acquired competencies in the techniques of Mendelian analysis
  • Be able to interpret the outcomes of crosses between monohybrids, dihybrids and multihybrids and define in detail the genotypes and phenotypes of all individuals.
  • Be able to calculate χ2 to decide whether observations of progenies ratios in particular crosses deviate from expectations purely on the basis of chance.
  • Be able to explain the results of dihybrid crosses and define in full detail the genotype and phenotype of all individuals intergenerational and intragenerational.
  • Be able to test experimental results in dihybrids crosses under different regimes of dominance and epistasis and use the χ2 test to reject or not a precise null hypothesis.
  • Have become familiar with the ways in which the environment affects the manifestation of the phenotype, the norm of reaction of a genotype, genotype-environment interactions, twin studies, and their applications.
  • Be able to calculate the estimated distance between linked genes based on outcomes for crosses involving these genes.
  • Be able to explain the outcomes of crosses between dihybrids for linked genes and define in detail the genotypic and phenotypic ratios of progenies in all generations.
  • Be able to perform a three – point testcross and draw a linkage map of the linked – genes, showing the order and the distance in map units.
  • Have familiarized themselves with the cell cycle, mitosis, meiosis.
  • Understand the mechanisms of sex determination in animals.
  • Learn about the structure of Υ chromosome and understand the importance of the SRY gene in the development of testis in mammals, while also interpret what causes sex reversal.
  • Learn about the structure of X chromosome and understand the importance of X-inactivation for the dose compensation through epigenetic mechanisms.
  • Understand the sex-linked inheritance and distinguish it from sex-influenced and sex-limited inheritance.
  • Learn about the types of gene mutations, how they are caused, and interpret their effects in protein structure and function as well as in diseases.
  • Know the types of chromosome mutations, such as deletions, duplications, inversions, translocations, and understand how they develop and their effect in individuals and their gametes.
  • Have understood how to use plant monosomic lines for a gene and, through appropriate crosses, identify the chromosome that carries the gene.
  • Have gained knowledge about extra-nuclear inheritance, the theory of endosymbiosis, the molecular genetics of mitochondria and chloroplasts, and human diseases associated with mutations in mitochondrial DNA
  • Have developed their ability to collaborate with other students to solve complex Genetics problems.

Bibliography

Concepts of Genetics (11th Edition) ISBN 0321948912, Klug, Cumminngs, Spencer, Palladino 2015 Pearson Education Inc.

NEWSLETTER

The Department of Food Science and Human Nutrition (renamed Department of Food Science and Technology, Decree 80/27/5/13, Government Gazette A119 28/5/13) offers its students the scientific background for a rational approach to scientific and technological issues related to the food sector.
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