C-value paradox

1. (DEPARTMENT OF BOTANY)

2.  Introduction
 Genome
 Definition
 History
 C – Value Paradox
 C-value Enigma
 Reason Of C-value Paradox
 Several Factors That Explains The Classic C-value Paradox
 Conclusion

3.  Quantity of DNA in an organism per cell in all cell is always constant
for a given species.
 The list of organisms on this planet with teaming millions, each have
its own genome whose size varies from one species to the other and no
two species have the same amount of genome nor the same genomic
value or character ?
 Variation in genomic content ( both qualitatively and quantitative)
within a phylum or an order or genus is surprisingly large from 10^5
BP to 10^12 bps.
 Animal show variations range more than 3,300-fold and in land
plants among them differ by a factor of about 1000, Protists
genome have been surprisingly vary more than 3000,000 fold in
size.

4.  In the fields of molecular biology and genetics, a genome is
all the genetic information of an organism.
 It consists of nucleotide sequences of DNA (or RNA in RNA
viruses). The nuclear genome includes protein-coding genes
and non-coding genes, other functional regions of the
genome such as regulatory sequences (see non-coding DNA),
and often a substantial fraction of ‘junk’ DNA with no
evident function .
 Almost all eukaryotes have mitochondria and a small
mitochondrial genome .
 Algae and plants also contain chloroplasts with a chloroplast
genome.

5. The C-value enigma or C-value paradox is a term used to describe the
complex puzzle surrounding the extensive variation in nuclear genome
size among eukaryotic species.
OR
C-value paradox is total amount of DNA present in genome expressed in
base pairs.
 The amount DNA Found in haploid genome , Measured in million base
pairs, or in pg; the C may mean constancy of the genome in the species.
 Genome size does not correlate with organismal complexity; for
example, some single- celled Protists have genome much larger than of
humans.

6.  The term of c-value paradox was used by C.A.
Thomas in 1971 .
 The term of c-value enigma was coined by
Canadian biologist Dr. T. Ryan Gregory of the
university of Guelph in 2000/2001.
 The discovery of non- coding DNA in the early
1970s resolved the main question of the c-value.

7.  The c-value paradox refer to the observation that genome
size does not uniformly increase with respect to perceive
complexity of organisms , for example Some Amphibians
have more than 10-fold more DAN than do Mammals,
including Human.
 Example in C-value
1. Mycoplasma - 10^5 bp
2. (-) Bacteria - 4.2 to 5×10^6 bp
3. (+) Bacteria - 2 to 8×10^6 bp
4. Algae - 5 to 8×10^7 bp
5. Warms - 7×10^7 to 2×10^8 bp
6. Insects - 1.5×10^8 to 6×10^9 bp
7. Mammals - 3×10^9 to 5×10^9 bp

8.  It is the clear from above value “as
completely increase the c-value
increase from simplex to complex
from”.
 “There linear relationship between
genome size and organism
complexity”.
Not true

9.  The Complexity related to c-value i.e. there is not linear relationship between
genome size and organism complexity
 Example- Housefly- 8.6×10^8
Drosophila – 1.4×10^8
(Both are in same group)

10. C-value enigma represent an
updated term of c-value paradox.
Coined by Dr. T. Ryan Gregory in
2001.
DNA consists of coding and
noncoding DNA.

11. Due to presence of repetitive DNA
i.e. the sequence which repeat In the
genome many times.

12. It was said that “ as complexity
increase the c-value increases from
simpler to complex from”.
But is not true.