Transcript Biological information - Ohio State University

Biological (genomic) information
Dan Janies
[email protected]
C Value paradox
The amount of DNA in the haploid genome of a species
does not correlate with its morphological complexity.
Transcription
polymerase forms mRNA from DNA
Translation
ribosome forms protein from mRNA
Regulation
CIS regulatory elements: DNA sequences in the vicinity of the
structural portion of a gene that are required for gene expression
such as:
promoters
enhancers
silencers
Trans-acting factors: proteins that bind to the cis-acting
sequences to control gene expression
such as:
products of regulatory genes
generalized
specific
Variation
Insertion-deletion mutations
GCC ATT TTT GGC CTT
delete T
GCC ATT TTG GCC TT.
GCC ATT TTG GCC TT.
insert T
GCC ATT TT T GGC CTT
Variation
Substitution mutations
Adenine
Guanine
Cytosine
Thymine
Transversions
Transitions
Variation
Transcriptional control can be
modified by the insertion of
transposable elements (e.g. Alu
sequences) or mutation.
Post-transcriptional variation
Alternative pre-mRNA splicing
have lately been shown to take
place for at least half of the genes
among human and other
eukaryotes. Differential splicing
is probably more the rule than the
exception.
C Value variation
Genome sizes among flowering plants vary
dramatically over almost 3 orders of
magnitude,
Genome size variation greatly exceeds
estimates of differences in gene numbers.
Plant genomes expand by several
mechanisms, including polyploidization,
transposition, and gene duplication.
Synteny:
comparison of genomic sequence data of two
different species facilitates the identification of novel
genes and conserved regulatory elements.
Population level variation
Natural selection
Sexual reproduction (independent
assortment in meiosis)
Gene flow
Genetic drift
Suggested Reading
ftp://ftp.amnh.org/pub/people/djanies/bmi731
White
FUNCTIONAL GENOMICS AND THE STUDY OF
DEVELOPMENT, VARIATION AND EVOLUTION
Searls
PHARMACOPHYLOGENOMICS: GENES,
EVOLUTION AND DRUG TARGETS
Rubin and Hall
PERSPECTIVES FOR VASCULAR GENOMICS