Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
Do you really want to delete this prezi?
Neither you, nor the coeditors you shared it with will be able to recover it again.
Make your likes visible on Facebook?
You can change this under Settings & Account at any time.
Transcript of Cytoplasmic Inheritance
-Homologous chromosomes segregate during gamete production
-Offspring get 1 copy of each gene from each parent
Non-Mendelian Inheritance Not associated with meiosis and mitosis; organelles in cytoplasm not nucleus
Mitochondria and chloroplasts don’t segregate into gametes Extra-nuclear inheritance
It is the transmission of genes that occur outside nucleus, located in cytoplasmic organelles Three General Types of Cytoplasmic Inheritance Uniparental
Chloroplasts have been found to exhibit various modes of inheritance within the same species Uniparental Inheritance •Only 1 parent contributes DNA from organelle to offspring
•Most common type of cytoplasmic inheritance
•Example: Maternal Inheritance-transmission of mother’s mitochondria at fertilization via the egg
•Can’t predict this inheritance Biparental Inheritance Both parents contribute DNA from organelles to offspring
When 2 haploid cells from both parents fuse, they both give their mitochondria to diploid offspring
Can be seen in some types of yeast; not very common Vegetative Segregation Replicative Segregation
Random replication and partitioning of cytoplasmic organelles
Occurs in chloroplasts and mitochondria during mitotic cell divisions resulting in daughter cells with random samples of parent cell’s organelles.
Example: Asexually replicating yeast cells Homoplasmy vs Heteroplasmy Demo Activity LHON (Leber’s hereditary optic neuropathy) Mitochondrial inheritance disease with incomplete penetrance
Reasons for incomplete penetrance include:
-Effect of heteroplasmy
-Effect of genetic interactions with nuclear genes
-Effect of environmental factors with the mitochondrial gene Figure 1: Pedigree showing maternal inheritance with incomplete penetrance of LHON. Summary •Cytoplasmic inheritance transmits genes carried on organelle chromosomes
•Cells or organisms in which all genomic copies of an organelle gene have identical sequence are said to be homoplasmic for that gene, whereas, cell or organisms possessing multiple alleles for an organelle gene are heteroplasmic
•Inheritance of organelle genomes can be uniparental, biparental or vegetative. Homoplasmic cell-all copies (alleles) of a cytoplasmic organelle gene are the same
Heteroplasmic cell-a mixture of alleles of an organellar gene