It's a useful tool in genomics study. Some information are collected and simply described to give a easily understandable idea.

2. Transcription is the process where from
DNA, the single stranded RNA is formed.
In this process DNA must be read and
transcribed. These gene readouts are called
transcripts, and the collection of all the
gene readouts present in a cell is called
transcriptome.
The study of the complete set of RNAs (transcriptome)
encoded by the genome of a specific cell or organism at a
specific time or under a specific set of conditions is called
Transcriptomics.

3. Transcriptomics is also called global gene expression or
trancriptome analysis.
In transcriptomics, the expression of genes by a genome is
studied
qualitatively (identifying which genes are expressed and
which are not) and
quantitatively (measuring varying levels of expression for
different genes)

4. Transcriptome analysis provides insights into:
 normal patterns of gene expression that are
important for understanding how a cell or tissue type
differentiates during development,
 how gene expression dictates and controls the
physiology of differentiated cells, and
 mechanisms of disease development that result from
or cause gene-expression changes in cells.
Transcriptome analysis provides gene expression profiles
that for the same genome may vary from cell to cell or
from tissue type to tissue type. Identifying genes
expressed by a genome is essential for understanding
how the genome functions.

5. Real time PCR
(quantitative
or semi-
quantitative)
• Able to detect genes
that are expressed at
low levels.
Microarray
expression
profiling
• It enables researchers
to analyze all of a
sample’s expressed
genes simultaneously
“next gen”
DNA
sequencing
or“RNA-Seq”
• delivers unbiased
information without the
need for prior knowledge
of the genome or
transcriptome

9. In University of Southern California Los Angeles,
California, U.S.A, researchers generated and compared the
transcriptomes of four globally distributed, bloom-forming
prymnesiophyte algae :
• Prymnesium parvum
• Chrysochromulina brevifilum,
• Chrysochromulina ericina and
• Phaeocystis antarctica
Transcriptomic approaches
provide a cost-effective
alternativefor examining
genetic potential and
physiological responses of
microbial eukaryotes to environmental stimuli.

10. Method followed by the group
* RNA isolation
* Library preparation
* Sequencing
* Transcriptome Assembly
* Transcriptome Annotation
* Polyketide synthase analysis
* KOG Analysis

11. A) Venn diagram showing the
number of shared or unique
genes (in italics) and gene
clusters (in bold)
B)Proportion of annotated
and unannotated genes in the
‘‘core’’ gene set,
C) Proportion of the
transcripts that comprised
core, shared and unique
genes.

12. • Four transcriptomes possess a set of core genes that are
similar in number and shared across all four organisms.
• The functional classifications of these core genes using
the Eukaryotic Orthologous Genes (KOG) database
were also similar among the four study organisms.
Clustering patterns (phylogeny and nutritional
modes) provide insight into genomic factors relating to
both evolutionary relationships as well as trophic ecology.

13. (a) Hierarchical clusters in a
microarray experiment
using RNA samples from
Saccharomyces cerevisiae
grown for varying times in
culture
(b) High (red), intermediate
(black),and low (green)
levels of gene expression
for a Drosophila genes
that exhibit a circadian
rhythm
a) The sea urchin
Strongylocentrotus
purpuratus.
b) Transcriptome analysis of
genes expressed in the sea
urchin embryo.

14. • Gene-expression analysis is gradually becoming an important
diagnostic tool in certain areas of medicine
• Genomic studies of bacteria, archaea and viruses have provided
insights into the microbial world by unveiling potential
functional capabilities and molecular pathways.
• It can also be used to investigate splicing patterns, splicing
variants, gene isoforms, single nucleotide polymorphisms and
post transcriptional modi໐cations.