Non-Mendelian Part 2

Can you explain this image?

A segment of DNA is "marked" with the mark retained and recognized throughout the life of the organism

Genomic Imprinting

Silencing of one of two alleles

Genomic Imprinting

When does Genomic Imprinting occur?

Occurs prior to fertilization

Attachment of a methyl group to a cytosine base

DNA Methylation

During DNA methylation, imprinting control region is methylated in the egg or sperm but not both. (Y/N)

Yes.

In DNA methylation, once imprinting control region is methylated in the egg or sperm, this will result in?

inhibition of transcription

Governs whether an offspring expresses a gene inherited from its mother or father

Genomic Imprinting

What are the Stages of Imprinting

1. Establishment of the imprint during gametogenesis

2. Maintenance of the imprint during embryogenesis and in adult somatic cells

3. Erasure and reestablishment of the imprint on germ cells

What is the rule that Epigenetics violates?

RULE #2:

Genes are passed unaltered from generation to generation

Inheritance of organellar genetic material

EXTRANUCLEAR INHERITANCE

Circular DNA molecule with 17,000bp

mtDNA

Carries few genes but has genes encoding proteins mainly for mitochondrial functions

mtDNA

100,000-200,000bp

cpDNA

Carries genes encoding proteins for photosynthesis

cpDNA

Mitochondria and chloroplasts are sorted during meiosis. (Y/N)

No.

What rule does Extranuclear Inheritance violates?

RULE #3 and #4

no segregation, no independent assortment

demonstrated that the pigmentation of the offspring of Mirabilis jalapa depended solely on the maternal parent = Maternal Inheritance

Carl Correns (1909)

What is the difference between Maternal Inheritance and Maternal Effect?

Maternal inheritance refers to the transmission of genetic material (like mitochondria) solely from the mother to her offspring,

Maternal effect describes instances where the mother's genotype influences the phenotype of her offspring.

From who is mtDNA inherited from? (Father or Mother)

Mother.

cell contains a mixed population of mitochondria

Heteroplasmy

Is mtDNA paternally inherited? (Y/N)

No.

mtDNA mutations accumulate as a person ages owing to limited repair capabilities. (Y/N)

Yes.