genetic unit 5 terms - mizzou birchler

transposable elements

segments of DNA that move from one location to another; makes up most of our genome

direct repeat

what is left behind when the transposable element Activator transposes to a new site in the genome

terminal inverted repeats

type of terminal repeat on activator and the P element

transposase

name of the enzyme encoded by the Activator transposable element that is required for the element to be excised from one location in the genome and insert elsewhere

retrotransposons

type of transposable element that has an RNA intermediate

retroviruses

single stranded RNA that are replicated via double-stranded DNA intermediate; can move from cell to cell

reverse transcriptase

the enzyme encoded in retroviruses and retrotransposons that converts RNA into DNA

long terminal repeats

the term for the ends of retrotransposons and retroviruses

homomorphic sex chromosomes

type of sex chromosomes that are not cytologically distinct

heteromorphic sex chromosomes

type of sex chromosomes that are cytologically distinct from each other

gynandromorph

an individual organism that is part male and part female

dosage compensation

the process by which sex chromosomes of different doses produce the same amount of gene products

pseudoautosomal region

name of the region shared between the X and Y chromosome of mammals

testis determining factor (TDF)

the gene on the Y chromosome that causes male development

Lyon hypothesis

the name of the hypothesis that one of the two X chromosomes in mammals is inactivated

Fragile X syndrome

The most common inherited form of mental disability in which there is a de-spiraled part of the X chromosome

- disorder produced by altered site at the tip of the long arm of X chromosome
- most common inherited cause of mental retardation in humans; rare in females but 1/1250 males
-characterized by mental disability, large head and ears, large testes in males

Turner's syndrome

Human syndrome resulting from only a single X chromosome present (also referred to as XO)

Klinefelter's syndrome

human syndrome resulting from an XXY genotype

TATA box

site slightly upstream of eukaryotic genes that is the main anchor for factors involved with gene expression.

CAAT box

A DNA sequence in proximity to promoter that influences promoter activity; usually occurs about 80 base pairs before start of transcription (so upstream of TATA box)

enhancer

regulatory DNA element that causes the adjacent gene to increase expression; it works in either orientation

silencer

Site where negative regulators (repressors) bind (attract repressors of transcription)

zinc finger

type of transcription factor in which a stretch of amino acids surrounds a zinc molecule

leucine zipper

type of transcription factor in which repeating leucines form an interaction domain

helix-loop-helix

transcription factor: three helices with two separated by a loop. Third helix has positive charges and is thought to be the DNA binding domain

totipotent

term applied to cells capable of giving rise to a completely developed organism

pattern formation

The cascade of developmental decisions that establishes the adult body plan

mosaic development

development type in which destruction of an embryonic cell leads to missing adult tissues

regulative development

Development type in which the destruction of an embryonic cell has no effect on the adult.

morphogenetic gradient

bicoid and nanos form these to initiate the morphology of a fly embryo

homeotic genes

Genes that determine basic features of where a body part is

homeotic mutations

mutation in segment identity genes that makes it possible to replace one part of a fly with another part (e.g. antennae to legs)

inductive interaction

developmental process in which one tissue has an effect on the differentiation of another

Ti plasmid

the name of the vector for plant transformation via Agrobacterium. tumor-inducing plasmid of soil bacterium causes tumorous growths

biolistic gun

apparatus used to transform organisms by coating gold particles with DNA and firing them into cells

retroviral vector

artificial DNA construct derived from a retrovirus, used to insert sequences into an organism's chromosomes (transgenes)

CRISPR-Cas9

A set of Cas proteins recognizes viral DNA pieces and incorporate them as spaces in the CRISPR DNA
a bacterial system that can be used either to produce a mutation in a specific gene or to correct a mutation that is already present

M

The designation of the stage of the cell cycle when chromosomes separate to daughter cells. mitosis (last stage in cell cycle)

G1 phase

Symbol for the stage of the cell cycle just preceding the stage in which DNA replicates
The pre-synthesis gap
The first gap, or growth phase, of the cell cycle, consisting of the portion of interphase before DNA synthesis begins.

S phase

Symbol for the cell cycle stage during which DNA replication occurs

G2 phase

The second gap, or growth phase, of the cell cycle, consisting of the portion of interphase after DNA synthesis occurs.

cyclins

proteins that regulate the cell cycle/determine the progression from one stage to the next

cyclin dependent protein kinases

proteins that activate genes for specific parts of the cell cycle and trigger the next stage by adding phosphate as an activation signal

tumor suppressor genes

type of cancer producing gene that acts as a recessive and requires both copies to be nonfunctional for cancer to develop

oncogenes

type of cancer-producing gene that acts as a dominant and that is a gain function mutation.

poly A tail

posttranscriptional addition to messenger RNAs at the 3' end

G cap

posttranscriptional modification to messenger RNAs at the 5' end

BACs

Cloning vector derived from the F plasmid and useful for large DNA fragments

cDNA

copy DNA

bioinformatics

the field of study involved with the analysis of DNA sequences for gene structure predictions.

single nucleotide polymorphism (SNP)

A single base-pair site in a genome where nucleotide variation is found in at least 1% of the population; can be used as genetic markers and associations between them and various genetic traits can be made to localize the genetic determinants of traits

RNA-Seq

This technique involves sequencing short segments of DNA derived from mRNAs.

apoptosis

the phenomenon that triggers the death of defective cells

Hox genes

genes involved with segment identity in animals

siRNA

act as defense against viruses and TEs (small RNA involved in post transcriptional gene silencing; siRNA often originate with dsRNA; they are most commonly a response to foreign RNA (viral or TEs) and is 100% complementary to target)

miRNA

type of small RNA encoded in the genome that inhibits translation of target mRNAs
acts as a regulatory mechanism for target mRNAs (small RNA involved in post-transcriptional gene silencing; miRNA made from endogenous genes; originates with ssRNA that forms hairpin secondary structure, part of which is double-stranded; regulates post-transcriptional gene expression and is often NOT 100% complementary to target)