Non Mendelian inheritance Maternal (organelle) inheritance Infectious inheritance Maternal effect on phenotype

1. WELCOME
TOPIC:-cytoplasmic inheritance.

2. Extranuclear Inheritance
Inheritance of traits from parents to off springs
from cytoplasmic organelle genetic material is known as
extranuclear inheritance or cytoplasmic inheritance.
it is mainly responsible due to DNA present in
cytoplasmic organelle.
total genes present in cytoplasm is know as as
plasmon.

3. History:-
 Carl corren in 4 o΄clock plant and baur in pelargnium
zonale in 1908.
 In 1924, jenkins described the iojap leaf variegation in
maize.
 Rhodes in cms in maize in 1933.
 Sonneborn discovered kappa particles in paramecium.
 Cp DNA discovered by Ris and Plaut in 1962.
 Nass and coworker discovered in mt DNA in 1954.

4. Features of cytoplasmic inheritance.
 Reciprocal inheritance.
 Lack of segregation.
 Irregular segregation in biparental inheritance.
 Somatic segregation.
 Association with organellar DNA.
 Nuclear transplantation.
 Mutagenesis
 Lack of chromosome.
 Lack of association with A Parasite,symbiont or virus.

5. Types of Extranuclear Inheritance
1. Maternal (organelle) inheritance
2. Infectious inheritance
3. Maternal effect on phenotype

6. Maternal (organelle) inheritance
 Eukaryote cells contain mitochondria (plants,
fungi, and animals) and chloroplasts (plants only).
 Both have genomes organized as a single circular
chromosome.

7. Chloroplasts
 vary between 120 & 217 kB, according to species
• 85kbps in chodia and 2000kbps in acetobularia.
• encode ~ 100 proteins, 4 rRNA &~30 tRNA
 5 classes of proteins
1. ribosomal & other proteins involved in translation
2. proteins involved in transcription
3. proteins involved in photosynthesis
4. proteins involved in respiration
5. ORFs (open reading frames)
sequences capable of encoding proteins but no product has
been identified.

9. Mito DNA
 range from 200 to 2500 kb (16 kb for mammalian mito)
 encodes ~ 35 proteins, also rRNA & tRNA
 subunits of ATP synthase & complexes I, II, III & IV
 mtDNA recombines to form new genes, some poison
pollen development to create cytoplasmic male sterility
 Pollen don't transmit mito, May be due to PCD (apoptosis)

11. Plastid inheritance.
Mirabilis jalapa in 1908.

12. Ovule Source
Pollen Source White Green Variegated
White White Green W, G, var
Green White Green W, G, var
Variegated White Green W, G, var
Leaf Color in Four O’Clocks

13. Chlaydomosanas reinhordtii (sager and coworker)
• Only one chloroplast is present per
cell. Antibiotic resistance comes
from mt+ cell. Mitochondria come
from mt- cell.
• Heteroplasmic cells allow
recombination between DNA in the
two choloroplasts

14. Mitochondrial inheritance
CMS

15. Mitochondrial Depletion Syndrome
 Mitochondrial Depletion Syndrome is a maternally
inherited disease characterized by multiple muscular and
neural symptoms, with a wide variety of severity in
different individuals.
 The severity of the condition is dependent on the number
of disabled mitochondria present in the egg.
 An egg with a large number of disabled mitochondria
would result in a child with severe abnormalities
 An egg with only a few disabled mitochondria would
result in an individual only mildly affected.
Ex:- LHON,Pearson marrow-pancreas syndrome.

16. Mitochondrial and chloroplast inheritance and
association with nuclear genes
IOJAB IN MAIZE.

17. Iojab in maize CGMS

18. Promiscuous DNA.
DNA segment that transfer from one organelle into the
other.
ex:- A.thaliana 400-2200genes in nucleus is by
endosymbionts.

19. Features of organelle genome
 Circular
 Multiple copies
 Encode RNA and protein for organelle
 In case of biparental recombination doesn’t take place
 Organelle DNA is replicated by nuclear DNA
 Accumulation of mutation is higher.
 CpDNA is larger.
 Recombination is less.

20. MATERNAL EFFECT
The maternal genome has a strong effect on early
developmental events in the newly formed individual
after fertilization.
Numerous transcripts are synthesized off the maternal
genome during oogenesis. These RNA transcripts are not
immediately translated; instead, they are preserved in the
oocyte.

21. The phenotype produced by these archived
products is expressed in the zygote (genetically
distinct from the mother) but is due entirely to the
genotype of the mother.

22. Coiling in Limnaea snails
Whether the shell coils to the
right or left is determined by the
maternal genotype and is
preserved in the oocyte. Dextral, or
right-handed coiling is dominant to
sinistral, or left-handed coiling.

23. crosses The direction of shell coiling is controlled
by the mother’s nuclear genotype
The direction of shell coiling in Limnaea is due to a
maternal developmental gene which controls the
orientation of the spindle in the second mitotic division
of the zygote

24. The life cycle of the protozoan Paramecium showing steps in
conjugation and autogamy.

25. Kappa particles of paramecium.

26. Genetic Imprinting.
 Describe a difference in the behaviour of allele of gene
contributed by the two parent af an individual.
ex:-IGF-II gene encoding in mice.

27. Endosymbiotic Hypothesis
 It is thought that chloroplasts and mitochondria
arose from ancient bacteria engulfed by primitive
eukaryotic cells.
 The cells developed a symbiotic relationship that
gave the eukaryotic cells the ability to respire
aerobically (mitochondria) and capture light
energy (chloroplasts).

28. Infectious Heredity
 An invading microorganism may exist in a symbiotic
relationship with its host organism. The invader is then
passed on in the maternal egg cytoplasm (ooplasm) and
confers the beneficial phenotype to the offspring.

29. Infectious Heredity in Drosophila
The responsible element is a protozoan. When ooplasm
from affected individuals or the protozoan itself is injected
into oocytes of normal individuals, the temperature-
sensitive, altered sex ratio condition results.
The condition is due to a sensitivity to a virus, sigma
CO2 sensitivity: Affected flies do not recover normally from
CO2 anesthesia. They become permanently paralyzed and
die.
Sex ratio: Affected flies produce predominantly female
offspring if reared at 21°C or lower. The condition is
transmitted only to daughters, not to the small number of
males produced.

30. REFRENCES
 GENETICS,B.D.singh,2nd edition,2009,Kalyani publishers.
 LIFE SCIENCE, funadmentals and practices-2, Pranav
Kumar and Usha mina 5th edition, 2016,path finder
publication.
 www.Slideshare.in