Chapter #6 Extranuclear Inheritance, Genomic Imprinting, and Maternal Effect

These flashcards cover key terms and concepts related to extragenetic inheritance, genomic imprinting, and maternal effects relevant to the lecture on BIO 2313.

Mendelian Inheritance

Inheritance patterns that obey The Law of Segregation and The Law of Independent Assortment.

Extranuclear inheritance

Traits inherited through genes that are not in the nucleus, located in organelles like mitochondria and chloroplasts.

Non-Mendelian Inheritance

Inheritance patterns that do not strictly follow Mendelian laws, including extranuclear inheritance and maternal effect.

Maternal Effect

Phenomenon where only the mother's genotype controls the phenotype of the offspring.

Genomic Imprinting

Modification of a nuclear gene that alters gene expression based on parental origin, leading to non-Mendelian inheritance.

Monoallelic expression

Expression of either the maternally-inherited or the paternally-inherited allele, but not both.

Heteroplasmy

Presence of more than one type of organellar genome within a cell, particularly in the context of chloroplasts and mitochondria.

Epigenetic Inheritance

Modification to a gene that changes gene expression, which may not be permanent and not involve changes in the DNA sequence itself.

Chloroplast Genome

A genome composed of a single circular double-stranded DNA chromosome found in chloroplasts.

Imprinting Control Regions (ICRs)

Regions near imprinted genes that contain transcription factor binding sites and play a role in genomic imprinting.

Mitochondrial Genome

The genetic material found within mitochondria, typically consisting of a single circular chromosome.

Mitochondrial Inheritance

Pattern of inheritance in which mitochondria are passed from the mother to offspring through the egg.

Maternal Inheritance Pattern

Inheritance pattern where traits are determined solely by the phenotype of the mother.

Paternal Leakage

Phenomenon where species with maternal inheritance may occasionally exhibit paternal inheritance of mitochondria.

Paternal and Maternal Alleles in Imprinting

Only the allele inherited from either the father or the mother is expressed, influenced by genomic imprinting.

Human Mitochondrial Diseases

Diseases resulting from mutations in mitochondrial genes, often leading to chronic degenerative disorders.

Expression of Imprinted Genes

Depends on the parent from which the allele is inherited, with one parental allele silenced.

Coiling in Snail, Lymnaea

An example of maternal effect genes where the direction of shell coiling is determined by the mother's genotype.

Stages of Imprinting

Includes establishment during gametogenesis, maintenance during embryogenesis, and reestablishment in germ cells.