Genetics

• The central dogma of molecular biology
• genetic material (חומר תורשתי)
• genetic variation (שׁוֹנוּת גֵּנֵטִית)
  • Mutations
  • genetic recombination

Realted branches

• molecular genetics
• genomics (גֵּנוֹמִיקָה)
• molecular biology
• bioinformatics
• biotechnology
• computational biology
• structural biology
• genetic engineering
• cytogenetics

DNA

• nucleic acids
• DNA sequence
• DNA sequencing
  • methods:
    • Sanger sequencing
• nucleic acid hybridization

DNA replication

• DNA replication (שכפול)
  • models:
    • conservative
    • semiconservative replication
  • primer
  • enzymes:
    • DNA ligase
    • DNA polymerase
• DNA repair
• natural DNA damage
• mutagen (מְתַשְׁנֵת)

non-coding DNA

• non-coding DNA (ncDNA)
  • cf. junk DNA (non-functional DNA)
  • examples:
    • cis-regulatory elements
    • RNA genes – from which a functional non-coding RNA (ncRNA) (e.g. tRNA, rRNA, miRNA, snRNA) is transcribed
    • introns
    • untranslated regions

Genes

• gene
  • protein-coding gene
  • regulator gene (or regulatory gene)
    • homeotic genes
    • cf. master regulator gene
  • pseudogenes
• allele (אָלֵל)
• locus (pl.: loci) – “a specific, fixed position on a chromosome where a particular gene or genetic marker is located” (Wikipedia)
• genome (גֵּנוֹם, מִכְלוֹל הַגֵּנִים)
• genotype (מערך גנטי)
• phenotype (מערך חזותי)
  • phenotypic trait

Gene expression

• gene expression (התבטאות גנים)

• transcription (תעתוק, שעתוק) – DNA → RNA

  • RNA polymerase (RNAP, RNApol)
  • alternative splicing (שִׁחְבּוּר חֲלוּפִי)
  • polysome (or polyribosome)
  • post-transcriptional modification
    • RNA splicing (שִׁחְבּוּר) – pre-mRNA → mRNA
      • exon
      • intron
      • precursor mRNA (pre-mRNA)
      • non-coding RNA (ncRNA)
      • spliceosome (שִׁחְבּוּרוֹן)
  • elongation (הִתְאָרְכוּת)
  • see also: promoter

• translation (תרגום) – mRNA → protein

  • codon
    • stop codon (or termination codon) – UAA, UAG, and UGA
    • start codon – AUG
  • anticodon
  • genetic code
  • ribosome
    • small subunit
    • large subunit
      • A site (aminoacyl site)
      • P site (peptidyl site)
      • E site (exit site)

Gene regulation

• gene regulation (or regulation of gene expression)
  • epigenetics
    • DNA methylation (מִתּוּל)
    • histone modification
  • microRNA
  • transcriptional regulation
    • transcription factor (גורם שעתוק) – “a protein that binds to DNA and regulates gene expression by promoting or suppressing transcription” (Wikipedia)
      • activator (מְשַׁפְעֵל)
      • repressor (דַכְּאָן)
    • cis-regulatory elements (CREs) – “regions of non-coding DNA which regulate the transcription of neighboring genes” (Wikipedia)
      • enhancer (מַעֲצֵם)
      • silencer (משתיק)
      • promoter (מְקַדֵּם, קַדָּם)
      • operator (מפעיל)
    • operon – “functioning unit of DNA containing a cluster of genes under the control of a single promoter” (Wikipedia)
  • post-transcriptional regulation
  • translational regulation
  • post-translational modifications (PTMs)
• X-inactivation (or Lyonization)

Gene mutations

• mutation (מוּטַצְיָה, תַּשְׁנִית)
  • mechanisms:
    • indel (insertion-deletion)
      • gene insertion (or insertion mutation) (הַחְדָּרָה)
      • gene deletion (or deletion mutation) (הַשְׁמָטָה, הֶשְׁמֵט, מוּטַצְיַת הֶשְׁמֵט)
    • substitution
      • transversion (הֶחְלֵף בְּשׁוֹנֶה)
      • transition (הֶחְלֵף בְּדוֹמֶה)
  • types:
    • point mutation

      • missense mutation (מוּטַצְיַת סֶלֶף)

      • nonsense mutation (מוּטַצְיַת פֶּסֶק)

      • silent mutation (מוטציה שקטה)

      • frameshift mutation (הסטת מסגרת)

  • transposable element (TE)
  • reading frame (מסגרת קריאה)

Chromosomes

• chromosome (כְרוֹמוֹזוֹם)

  • types:
    • autosome
    • sex chromosome (or allosomes)
      • X chromosome
      • Y chromosome
      • see also: biological sex (or sex) (זוויג, מין)
      • dosage compensation
  • structure:
    • centromere (צֶנְטְרוֹמֵר)
    • telomere (טֵלוֹמֵר)
      • see also: telomerase (or terminal transferase)
    • chromatid (כְּרוֹמָטִידָה)
    • chromatin (כְּרוֹמָטִין)
      • nucleosome
        • histones
          • heterochromatin
          • euchromatin
          • histone tails
    • p-arm (short)
    • q-arm (long)
    • sister chromatid

• karyotype

• homologous chromosomes (or homologous pair, homologs) (שווה מוצא) – “A pair of chromosomes of the same length, centromere position, and staining pattern that possess genes for the same characters at corresponding loci” (Campbell, 2020)

• DNA content

• cytogenetics (גנטיקת הגרעין)

• dominant allele – “An allele that is fully expressed in the phenotype of a heterozygote” (Campbell, 2020)

• recessive allele – “An allele whose phenotypic effect is not observed in a heterozygote” (Campbell, 2020)

• dominant trait – a phenotypic trait produced by a genotype containing at least one copy of the corresponding dominant allele

• recessive trait – a phenotypic trait produced by a genotype containing two copies of the corresponding recessive allele

• codominance

• incomplete dominance

• zygosity

  • homozygous (שְׁוֵה אָלֵלִים, הוֹמוֹזִיגוֹט) genotype has identical alleles at corresponding loci on a pair of homologous chromosomes.
    • notation: $AA$ or $aa$
    • cf. homozygote
  • heterozygous (שׁוֹנֵה אָלֵלִים, הֵטֵרוֹזִיגוֹט) genotype has different alleles at corresponding loci on a pair of homologous chromosomes.
    • notation: $Aa$
    • cf. heterozygote

Chromosome mutations

• chromosome mutation (or chromosome aberration)
  • structure
    • chromosomal inversion (היפוך כרומוזומלי)
    • chromosomal translocation (התקה כרומוזומלית)
  • nubmer
    • aneuploidy ($2n\pm x$ chromosomes)
      • monosomy ($2n-1$)
      • dissomy ($2n$)
      • trisomy ($2n+1$)
    • euploidy
      • see: Ploidy

Mendelian genetics

• Mendelian inheritance (or Mendelism) (תּוֹרָשָׁה מֶנְדֶלְיָאנִית)

• Punnett square (ריבוע פַּ֫נֶט)

• Law of independent assortment (חוק ההתפלגות הבלתי תלויה)

• Law of segregation (חוק ההיפרדות)

• Law of dominance and uniformity

• hybrid (בֶּן-כִּלְאַיִם, מִכְלוֹאיו)

  • monohybrid
  • dihybrid

• hybridization (הַכְלָאָה) (Not to be confused with nucleic acid hybridization)

  • monohybrid cross (הכלאה מונוהיברידית)
    • $P:AA\times aa$
      • $F_1:Aa$
      • $F_2:1AA:2Aa:1aa.$
  • dihybrid cross
    • $P:AABB\times aabb$
      • $F_1:100\%AaBb$
    • $F_1:AaBb\times AaBb$
      • $F_2:1AABB:2AABb:1AAbb:2AaBB:4AaBb:2Aabb:1aaBB:2aaBb:1aabb$

• P generation (parental generation)

• F₁ generation

• F₂ generation

• test cross (הכלאת מבחן)

• heredity (or biological inheritance) (תּוֹרָשָׁה)

• genetic linkage (תַּאֲחִיזָה בין גנים, תאחיזה גנטית)

  • linkage group

extensions of Mendelian genetics

• epistasis (מִסּוּךְ גֵּן)
  • modifier genes
• pleiotropy

Reproduction

• sexual reproduction (רְבִיָּה מִינִית)

• asexual reproduction (רְבִיָּה אַל-מִינִית)

• reproductive cell (תא רבייה)

  • gamete* (or sex cell) (גָּמֵטָה, תא מין, תא זוויג)
    • sperm (pl.: sperm or sperms) (זרע)
      • spermatozoa
      • spermatozoon
      • spermatia
    • egg cell (or ovum (pl.: ova)) (בֵּיצִית, תא ביצה)
  • germ cell (תא תחילי, תא נבט)
  • precursor cell (or blast cell)

• somatic cell (or vegetal cell) (תא גוף)

• stem cell (תא גזע)

• zygote (בֵּיצָה מֻפְרֵית, זִיגוֹטָה)

• fertilization (הַפְרָיָה)

  • allogamy (or cross-fertilization) (הַפְרָיָה הֲדָדִית, זִוּוּג שׁוֹנִים)

• meiosis (חֲלֻקַּת הַפְחָתָה)

• chromosomal crossover (or crossing over)

  • cf. genetic recombination (or genetic reshuffling)

• in plants

  • gametophyte
  • sporophyte

Ploidy

• ploidy (סִדְרָתִיּוּת)
• haploid number ($n$) – the number of chromosomes in one haploid chromosome set of an organism
  • humans: 23
  • Triticum aestivum: 21
  • Solanum tuberosum: 24
• monoploid number ($x$) (or basic chromosome number) – the number of distinct chromosome types in one basic chromosome set
  • humans: 23
  • Triticum aestivum: 7
  • Solanum tuberosum: 12
• $n/x$ is number of sets in a haploid cell
  • humans: 1
  • Triticum aestivum: 3
  • Solanum tuberosum: 2
• ploidy level ($p$ or $k$) – the number of basic chromosome sets present in a cell
  • monoploid: 1
  • diploid: 2 (e.g. somatic cell of human)
  • triploid: 3
  • tetraploid: 4 (e.g. somatic cell of Solanum tuberosum)
  • pentaploid: 5
  • hexaploid: 6 (e.g. somatic cell of Triticum aestivum)
  • chromosome number ($N=px$) – the total number of individual chromosomes in a cell
    • human:
      • gamete: 23
      • somatic cell: 46
    • Triticum aestivum:
      • gamete: 21
      • somatic cell: 42
    • Solanum tuberosum:
      • gamete: 24
      • somatic: 48

Genomics

• Short tandem repeat (STR) analysis
  • STR marker

Genetic engineering

• genetic engineering (or genetic modification)
• genetically modified organism (GMO)
• transgene
• recombinant DNA (rDNA)
• gene knockout (הַשְׁבָּתַת גֵּנִים)

References

• Campbell, Neil Allison (2020). Campbell Biology. Pearson Education.