Molec Cell Bio E2 Chap 8 Membrane

Germ line

The cell lineage which contributes to the formation of the next generation by producing gametes.

Somatic cell

any non germ line cell in a multicellular organism.

somatic cell mutations

may affect the individual with the mutation

germ line cell mutations

will not affect the individual, but may be passed to the next generation and may result in an heritable trait.

mutation within a gene

creates an altered product

mutation within a regulatory region

will alter its expression

gene duplication will

create a new gene family.

horizontal transfer

is the acquisition of new genomic information from organism to organism, not through reproduction.

effect on regulatory regions on gene expression

difference in regulatory DNA can control gene expression, closely related species in an extreme example vary only due to the timing and location of the regulatory switches do they evolve to become vastly different species

Ectopic expression of anntenapedia

Antennapedia gene which is necessary for leg development needs regulatory proteins which would logically be found in legs. However, if artificially placed in head, the correct proteins exist to begin the development of legs.

Lactose and selection

Digestion of lactose is due to a mutation of regulatory DNA of lactase gene which allows enzyme to be made beyond infancy. Selected for in Northern European and Central Africa where humans first domesticated cattle.

Globin gene family

all originate from a common ancestral gene. Code for subunits of hemoglobin

Hemoglobin function

transports O2 in circulatory system

Structure of globin genes

Three exons and two introns

Different versions of globin exist throughout the

fetal embryonic, and adult stages.

What are non functional genes called

pseudogenes (non functional genes)- some members of globin genes are these.

Adult version contains what subunits

two alpha and two beta subunits

A single chain globin can bind to x oxygen, and evolution of such leads to

one oxygen molecule, evolution of second globin chain occurs when there is a duplication followed by a mutation.

Four chain hemoglobin can bind to x oxygen molecules

four oxygen molecules in a cooperative way.

which chromosomes are the alpha globin cluster and the beta globin cluster

alpha : 16. beta: 11

Which globin's have higher affinities for oxygen

embryonic and fetal.

Gamma globin is found in fetal humans beacuse

maternal blood is less O2 rich, and they do not take it in from the atmosphere.

How did globin gene family arise

gene duplications

How does gene duplication occur by unequal crossing over

short repeated sequences within homologous chromosomes may cause misalignments and unequal crossing over.

transposition of mobile genetic elements may mediate

recombination of genes or regulatory sequences

If two mobile genetic elements are next to eachother,

transposition mechanism may use ends of two different transposition elements and move the entire segment of the chromosome between them.

transposition of regulatory sequences may

alter tissue specific pattern of gene expression

Exon shuffling and duplication and movement of DNA segments

can result in the origin of new proteins by piecing together fragments of different genes.

New proteins which result from exon shuffling and movement DNA segments

New proteins with multiple functional domains

vertical transfer

parent to progeny through gametes

horizontal transfer examples

viral infections, conjugation in between bacteria via a sex pilus

Genetic recombination without reproduction is

conjugation via a sex pilus between bacteria (horizontal gene transfer)

ALS stands for

amyotrophic lateral sclerosis aka lou gehrigs disease

ALS is caused by HERV-K which stands for

Human endogenous retrovirus K which was incorporated into human DNA 2-5 million years ago.

HERV-K is what in ALS patients

elevated, which shows the virus had come to life in these patients

HERVs are

retroviruses that infect neurons and germ cells. They have been linked to ALS and germ cell-derived tumors in the testes and ovaries.