Bio ch 18 pt 2

Laminopathies

Disorders linked to mutations in lamin proteins affecting nuclear organization and gene expression

Heterochromatin

Condensed, silenced regions of chromosomes attaching to lamins

Differential Gene Expression

Process where cells express specific genes based on specialization

Housekeeping Genes

Genes expressed in all cells for basic cellular functions

Tissue-Specific Genes

Genes expressed in specific tissues for specialized functions

Cell Differentiation

Process where cells become specialized in form and function

Control Elements

Noncoding DNA segments regulating gene transcription by binding proteins

Proximal Elements

DNA sequences close to the promoter essential for transcription initiation

Distal Elements

DNA sequences far from the promoter enhancing transcription activity

Enhancers

DNA sequences enhancing transcription activity at the promoter

General Transcription Factors

Proteins essential for transcribing all protein-coding genes

Transcriptional Activators

Proteins binding to enhancers to stimulate gene transcription

Pre-initiation Complex

Assembly of proteins at the promoter to initiate transcription

Histone Acetylases

Enzymes adding acetyl groups to histone proteins to affect transcription

Chromatin Remodeling

Process altering chromatin structure to regulate gene expression

Post-transcriptional Regulation

Regulatory mechanisms acting after transcription to fine-tune gene expression

Alternative Splicing

Process generating multiple proteins from a single gene by selecting different exons

mRNA Degradation

Breakdown of mRNA by nucleases, affecting protein synthesis

mRNA Stability

Enhanced by 5' cap and 3' poly A tail, preventing degradation

Translation Initiation

Process of starting protein synthesis, influenced by RNA folding

Proteasomes

Giant protein complexes degrading unwanted proteins in cells

Ubiquitin Tagging

Addition of ubiquitin to mark proteins for proteasomal degradation

Noncoding RNAs

Regulate gene expression by blocking translation or promoting degradation

MicroRNAs (miRNAs)

Small RNAs binding mRNA to degrade or block translation

Chromatin Condensation

Induced by ncRNAs, affecting gene expression and methylation patterns

Embryonic Development

Regulated gene expression leading to cell specialization and morphogenesis

Morphogenesis

Physical processes shaping an organism

Cytoplasmic determinants

Maternal substances influencing early development

Inductive signals

Signals causing transcriptional changes in nearby cells

Coordinately controlled genes

Genes with shared control elements for coordinated expression

Sequential regulation of gene expression

Orderly control of gene activity during cellular differentiation

Determination

Committing a cell to its final fate

Differentiation

Production of tissue-specific proteins in cell development

Myoblasts

Cells producing muscle-specific proteins

MyoD

Master regulatory gene for skeletal muscle development

Transcription factor

Protein binding to DNA to regulate gene expression

Pattern formation

Development of spatial organization of tissues and organs

Positional information

Molecular cues guiding cell location in body axes

Major axes

Anatomical reference points (A/P, D/V, L/R) in body formation

Homeotic genes

Genes encoding transcription factors for embryonic development

Homeobox

DNA sequence encoding a homeodomain in transcription factors

Homeodomain

DNA binding domain in transcription factors

Evolutionary developmental biology

Study of evolution's impact on multicellular organism development

Conservation of homeotic genes

Similarity in gene sequences across different species

Maternal effect genes

Genes encoding cytoplasmic determinants for axis establishment

Bicoid gene

Maternal effect gene controlling the anterior of Drosophila

Morphogen

Molecule gradient establishing embryo axes and polarity

Embryonic lethal

Mutation causing embryonic death

Ras

Gene involved in cell signaling pathways

Operon

Genes with a promoter and control elements for coordinated expression