Part 2 Flashcards
In Vitro Fertilization
process by which fertilization of an egg by a sperm occurs outside of the body
What does the IVF process entail?
step 1: ovulation induction- fertility drugs (gonadotropins: Repronex, Follitism, Gonal, Menopur)
step 2: egg (oocyte) retrieval-retrieved by ultrasound-guided procedure needle is placed through the vagina into ovaries
step 3: fertilization in lab (eggs are analyzed for maturity + incubated, sperm sample collected/examined then injected through intracytoplasmic sperm injection (isci)
step 4: embryo transfer- catheter w/ embroyos+liquid passed through cervix into uterus 3 days after retrieval (6-8) cell stage
How long does a zygote take to mature in liquid culture
2-6 days
infertility + causes
1 year of attempting to conceive without success where the mother is younger than 35
6 mos of trying in mother 35 older
- failure to ovulate
- tubal blockage
- absence of implantation
- reduced sperm transport
- low sperm count
advanced maternal age is a risk factor for adverse outcomes
miscarriage
live births with congenital abnormalities
what (%) of eggs in women at least 40 yo have genetic problems
75%
How long does it take to determine if fertilization has occurred?
18 hours
How long does it take to determine if the embryo is growing?
24-72 hours
how long do oocytes + embryos stay in the lab during a successful iVF procedure
2-5 days
What does blastocyst transfer do?
allows the # of embryos to bw kept at a minimum, reducing chances for multiple births
blastocysts
5-6 day old embryos that have advanced 30-60 cells and are transferred 5 days post retrieval
2PN
3PN
1PN
embryo grading system (day 2/3- cleavage stage)
- normally fertilized egg(2 pronuclei)
- has 3 complete sets of DNA (doesnt get rid of polar body)
- one gamete is….
Pre-Implantation Genetic Diagnosis (PGD)
testing an embryo for a specific disease
diagnosis of a single gene defect (25-50% risk of transmitting illness)
Pre-Implantation Genetic (Screening)
testing an embryo for a specific disease
aneuploidy- age, previous miscarriage, repeated IVF fertilizations
this is the term used more frequently by reproductive endocrinologists when discussing
aneuploidy
abnormal number of chromosomes
embryonic development
- cleavage stage
- morula
- blastocyst
- hatching
- implantation
etiology
the (set of) causes of a disease
inherited diseases/traits based on genomics
- ovarian
- breast cancer
- hemophilia A
- Duchenne’s muscular dystrophy
DNA chemical bases
Adenine–Thymine
Cytosine–Guanine
genome/genomics
complete set of DNA/
study of genomes through dna analysis
Reproductive genomics
wide array of genetic tests that are conducted with the intent of informing individuals about the possible outcomes of current/future pregnancies
National Center for Biotechnology Information (NCBI)
houses databases of biological information and all the sequenced genomes
Basic Local Alignment Search Tool (BLAST)
program which can detect sequence similarity between a Query sequence and sequences within a database/assigned sequences
BRCA 1/2 genes are located on which chromosomes
17/13
for the average woman, what is the lifetime risk for breast cancer? ovarian cancer
12%
2%
BRCA 1/2 can increase these risks for breast cancers? ovarian cancer
36-85%
20-60%
BRCA associated cancer is thought thought to develop in a person with
1 functional copy of a BRCA gene and one mutant copy
pedigree charts
diagram showing the genetic history of a family over several generations
Polymerase Chain Reaction
molecular diagnostic technique
- -diagnosis of genetic/infectious gene
- -cancer detection
- -forensics
- PGD
how does PCR determine sex
amplifying sex specific DNA sequences makes many copies of a particular region
key components of reaction are template DNA, primers, nucleotides
template dna
double stranded genomic DNA isolated from the cells of the organism being studied
the master DNA from which all other strands will be synthesized
primers
short pieces of DNA made in a lab
2 primers are designed to match to the segment of DNA you want to copy
–one primer attaches to the top strand at one end of segment and one primer to the bottom strand at the other end
nucleotides
building blocks that DNA molecules are made of
taq ploymerase
naturally ocurring complex of proteins whose function is to copy a cell’s DNA b4 it divides into 2
how many temperature change cycles does a PCR consist of
20-45
Denaturation, annealing, extension
Denaturation
heated to high temperature (94-98 C) melts DNA hydrogen bonds causing split into 2 single strands
Annealing
cooled (50-65 C) primers (2) to bind to each of the strands
primers=starting point for DNA synthesis
Extension
taq polymerase syntesizes a new DNA strand complementary to DNA template by adding free dntps
Agarose gel Electrophoresis
technique used to separate the DNA fragments and identify them according to their size
agarose
gel composition–> polymerizes to form a solid matrix with microscopic pores
phosphate groups
chemical structure–why DNA is able to migrate-negatively charged
when the DNA is placed in a solution that is near neutral ph–DNA will migrate towards the postitibve electode
smaller fragments travel at a faster rate –further
cytogenics
study of chromosomes
karyotype
test to identify/evaluate the size, shape and number of chromosomes in a sample body of cells
karyotyping
systematic arrangement of chromosome pairs in descending order of size
shortest arm orientated toward the top
formula: total number of chromosomes, notation of sex chromosomes
trisomy male: 47, XY, +18
monosomy female: 45, XX, -22
toxicology
studies of the effects of toxins on human health
reproductive toxicology
study of how toxins (natural/artificial) impact human reproductive health
endocrine disruptors
specific class of toxins which disrupt the endocrine system
cause cancerous tumors, fetal growth retardation, severe developmental abnormalitiees such as birth defects
examples of breast cancers associated with ED’s
breast cancer
prostate cancer
gliobastoma
Long term effects caused by EDs
feminizing of males/masculinizing effects on females obesity diabetes infertility abnormal brain developments
examples of endocrine disruptors
polycylic aromatic hydrocarbons DDTS Phytoestrogens Bisphenol A Xennoestrogens
2 reliable techniques that require culturing mitotic cells , then arresting these cells at the metaphase stage to visualize individual chromosomes
chromosomal preparations
banding
2 types of chromosomal abnormalities
- numerical
- structural (deletions/gaps)
can be both
