cytoplasmic Inheritance

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For the students of Veterinary Science

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Cytoplasmic Inheritance: 

Cytoplasmic Inheritance AGB121 Dept. Of AGB Veterinary College, Hebbal , Bangalore

Definition: 

Definition Factors inherited from a source other than Nucleus Also called Extra nuclear inheritance Extra chromosomal inheritance Maternal Inheritance 2 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

Types of Cytoplasmic Inheritance: 

Types of Cytoplasmic Inheritance 1. Plastid Inheritance 6. CO 2 sensitivity 2. Male sterility in plants 7. Coiling in snails 3. Streptomycin resistance 8. Eye colour in beach hoppers 4. Enzyme controlled 9. Cancer producing milk virus in mice 5. Killer particles 3 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

Plastid Inheritance: 

Plastid Inheritance (Carl Correns 1908) Inheritance of Chloroplastids only through maternal egg 4 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

Plastid Inheritance: 

Plastid Inheritance 5 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

Male sterility in Plants: 

Male sterility in Plants Rhodes M M Male sterility genes are inherited in cytoplasm of the female gametes. 6 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

Coiling in Snails: 

Coiling in Snails 7 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

CO2 sensitivity in Drosophila L'Heritier and Teisser(1958) : 

CO2 sensitivity in Drosophila L'Heritier and Teisser (1958) When reciprocal crosses were made between CO 2 sensitive and normal strains, it could be shown that the trait was inherited only from female parent. This sensitivity can be attributed to a virus like particle called sigma found in cytoplasm of the cells of a sensitive fly True breeding strain of Drosophila which was sensitive to Co 2 Sensitive flies become unconscious when exposed to CO 2 and are paralysed 8 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

Killer Particle Paramaecium: 

Killer Particle Paramaecium Dominant allele K is required for production of – Kappa Particles in cytoplasm KK or Kk are Killer strains if Kappa particles are present in the cytoplasm Without kappa particles they become sensitive strains Sensitive strains are kk normally Certain Killer strains posses Kappa particles which synthesize paramecin 9 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

PowerPoint Presentation: 

No Cytoplasmic Exchange Cytoplasmic Exchange Killer strain is formed when there cytoplasmic exchange Sensitive strain KK & kk 10 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

Milk factors in Mice: 

Milk factors in Mice 1936, by Dr. John Joseph Bittner Cancerous agent, or "milk factor", could be transmitted by cancerous mothers to young mice from a virus in their mother's milk. If the mice were fed milk from foster mother they did’nt get cancer. 11 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

Phenocopy: 

Phenocopy A phenocopy is an individual whose phenotype (generally referring to a single trait), under a particular environmental condition, is identical to the one of another individual whose phenotype is determined by the genotype. The environmental agents producing phenocopies includes temperature, shock, radiation, and various chemical compounds 12 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

Phenocopy In Drosophila melanogaster  T.H. Morgan in 1910 : 

Phenocopy In Drosophila melanogaster T.H. Morgan in 1910 . Larva of normal flies were fed with silver salts, develop into yellow bodied flies irrespective of their genotype The normal body colour is brownish-gray with black margins The yellow bodied flies which are genetically brown is a variant of the original yellow bodied fly. 13 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

Phenocopy in Himalayan Rabbits: 

Phenocopy in Himalayan Rabbits However when raised in colder climates, they become phenotypically distinguishable. Himalayan rabbits are white in colour with black tail, nose, and ears when raised in moderate temperatures. They show black colouration of their coats, resembling the genetically black rabbits. Hence this Himalayan rabbit is a phenocopy of the genetically black rabbit 14 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

Freemartin: 

Freemartin Infertile female when born as a co-twin to a male calf The calf will have masculanized behaviour and non functioning ovaries 15 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

Karyotype of freemartin: 

Karyotype of freemartin It is Chimeric with the sample of cells showing XX/XY chromosomes. and pigs Externally, the animal appears female, but various aspects of female reproductive development are altered due to acquisition of anti- Müllerian hormone from the male twin. It also occurs occasionally in other mammals including sheep, goats and pigs 16 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

Freemartinism: 

Freemartinism The animal originates as a female (XX), but acquires the male (XY) component in utero by exchange of some cellular material from a male twin, via vascular connections between placentas 17 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

Lethal Genes: 

Lethal Genes 18 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

Lethal Genes: 

Lethal Genes Genes with regularly fatal effects are called lethal genes Some lethal genes are completely recessive and produce no effect in heterozygous state Some maybe semi lethal or sub-lethal in heterozygous state such genes modify the classical Mendelian Ratio Some lethals may be dominant 19 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

LETHAL GENE: 

20 LETHAL GENE A lethal gene causes death of individual in the appropriate genotype before they reach adulthood. 1904 French geneticist Lucien Cuenot , discovered a recessive lethal affecting coat colour in mice. Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

LETHAL GENE: 

21 LETHAL GENE Y ellow colour is dominant C rossing 2 yellow mice the ratio was 2:1 ratio Crossing yellow with recessive wild type (grey) it was found that all were yellow. Concluded all yellow mice were heterozygotes . Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

LETHAL GENE: 

22 LETHAL GENE Later it was suggested that homozygosity for yellow is lethal, and that these individuals died in utero , a fact observed by histological studies. Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

Lethal Alleles: 

Lethal Alleles Example: Manx cat M L = tailless, lethal in homozygote m = tail The allele interferes with normal spinal development, in heterozygous cats this results in lack of a tail. 23 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

Manx Cat: 

24 Manx Cat M m M MM Lethal Mm Tailless m Mm Tailless mm Normal Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

Lethal Genes – Creeper Chickens: 

Lethal Genes – Creeper Chickens 25 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

Lethal Genes in Mexican hairless dogs: 

Lethal Genes in Mexican hairless dogs Hh hairy normal trait Hh hairless one mutation present HH lethal two mutations = lethal 26 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

PowerPoint Presentation: 

27 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

Dexter and Kerry: 

Dexter and Kerry It is sub-lethal The heterozygous condition results in short legged Dexter cattle 28 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

Bull dog calves: 

Bull dog calves Caused by single recessive gene in homozygous condition Calves are aborted at 6-8 months Abnormal head with short face and short upper jaw, short legs and cleft palate 29 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

Other conditions in Cattle: 

Other conditions in Cattle Parrot beak- In homzygous recessive state Amputated- Condition where the head legs and lower jaw are missing Short spine- Compacted vertebrae ,the calf dies at or before birth 30 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

Lethal conditions in Human: 

Lethal conditions in Human Sickel cell Anaemia Cooley’s anaemia or Thalassemia major Juvenile idiocy- deterioration of mental and physical powers caused by recessive lethal genes Infantile- Death of the child at 2-3 years of age Blindness- Colour and night blindness caused by recessive genes in homozygous recessive state Epidermolysis - Blisters on the skin- Homozygous recessive genes 31 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

PLEIOTROPY: 

32 PLEIOTROPY - Impact of a single gene on more than one characteristic - Sickle-cell disease - Most common inherited illness among black people - RBCs are sickle-shaped Can cause many problems RBCs: Sickle-cell disease Normal RBCs Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

Sickle Cell Anemia: 

33 Sickle Cell Anemia Under conditions of low oxygen tension , hemoglobin S will precipitate, causing cells to sickle Mutations in same amino acid Some individuals die in childhood; Some individuals have mild symptoms HbA: V – H – L – T- P – G –G HbS: V – H – L – T- P – V –G Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

PowerPoint Presentation: 

34 Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore

Achondroplasia: 

35 Achondroplasia The most common form of dwarfism, with a normal length body trunk but shortened limbs. Dr R Jayashree, Asst. Prof(AGB), Veterinary College, Bangalore