Lecture A10, A11 Flashcards
(110 cards)
1
Q
fertilization (def.)
A
sperm meets egg (haploid + haploid = diploid)
2
Q
sperm is the only human cell type that has ______
A
a flagellum
3
Q
sperm evolved specifically for _____
A
the delivery of DNA
4
Q
head of sperm contains _______
A
acrosomal vesicle, haploid nucleus
5
Q
midpiece of sperm contains _____
A
a lot mitochondria to propel movement
6
Q
the flagellum of sperm is _____
A
the motile part
7
Q
sperm is produced by _____
A
spermatogium through meiosis
8
Q
maturing spermatogonium remains ________ throughout their differentiation
A
connected by cytoplasmic bridges
9
Q
in the process of sperm differentiating, this happens?
A
most of the cytoplasm is discarded as residual bodies
10
Q
process of sperm production
A
1) spermatogonium
2) spermatogonia
3) primary spermatocytes
4) secondary spermatocytes
5) spermatids
6) differentiating spermatids
7) mature spermatozoa
11
Q
unipotent sperm cells
A
spermatogonium
12
Q
primary spermatocytes becomes secondary spermatocytes through ______
A
first meiotic division
13
Q
secondary spermatocytes becomes spermatids through ______
A
secondary meiotic division
14
Q
spermatogonium becomes spermatogonia becomes through ______
A
mitosis
15
Q
niche of oocyte is _____
A
the ovary
16
Q
cells that creates oocyte niche
A
granulosa cells
17
Q
granulosa cells produces ____ which do what?
A
-steroids (ex. estradiol) and growth factors
-that interact with oocyte during its development
18
Q
following ovulation, the granulosa cells do what?
A
changes into luteal cells that produce progesterone
19
Q
steps of oocyte production
A
1)primordial follicles
2)primary follicle
3)secondary/antral follicle
4)mature/graafian follicle
5)corpus luteum
6)corpus albicans
20
Q
primordial follicles comes from _____
A
oocyte stem cells
21
Q
corpus luteum & corpus albicans are from _______
A
granulosa cells
22
Q
zona pellucida (def.)
A
specialized extracellular matrix that surrounds the PM of oocyte
23
Q
corpus luteum & albicans function
A
hormone signalling that encourage fertilization
24
Q
generally, how many oocyte finishes differentiation each month from puberty until menopause?
A
one oocyte
25
stage of oocyte in primary follicle
-primary oocyte
26
stage of oocyte in secondary follicle
-primary oocyte
27
stage of oocyte in mature follicle
-secondary oocyte
28
how many polar bodies produced in oogenesis?
2 polar bodies
29
egg and sperm are both derived from _____
primordial germ cells (PGCs)/ stem cells
30
PGCs are not ______
part of 3 germ layers
31
lineage of oocyte from PGCs
-PGCs migrate
-oogonia proliferate and germ cell nest form
-nest breakdown
-primordial follicle formation
32
at week 3, human PGCs are ______
specified early during development
33
early PGCs in ______ move forming the _______ with ______
-yolk sac
-genital ridge
-migratory/gonadal PGCs
34
Imprinting (def.)
epigenetic information that controls which allele is expressed (paternal vs maternal)
35
imprinting is ______ in somatic cell during embryonic development
maintained
36
imprinting is ______ in PGCs during germ cell development
removed
37
imprinting is ______ in gametes during gametogenesis
re-established
38
imprinting is ______ in iPS cell during induced pluripotent stem cell development
maintained
39
majority of genes are not _______
imprinted
40
mendelian rules are not followed if ____
genes are imprinted
41
example of imprinting
DNA methylation
42
NANOG encodes a ________ that _____ by ______
-homeobox transcription factor
-helps embryonic stem cells (ESCs) maintain pluripotency
-suppressing cell determination factors
43
signalling that PGC specification
WNT/BMP
44
genes that program germ line cells (part of PGC circuitry)
PRDM1
PRDM14
TFAP2C
45
genes that program pluripotency genes (marks stem cells)
OCT4
NANOG
46
________ (also known as Blimp1) does what ?
-PR domain zinc finger protein 1 (Prdm1)
- is a repressing TF of somatic genes
47
Loss of Prdm1 blocks _____ in mice
-primordial germ cell formation
48
PRDM14 does what?
suppresses somatic genes and activates germ cell genes
49
AP2γ is what?
a HLH protein, encoded by the Tcfap2c gene - Transcription factor ap2 c (c = γ)
50
AP2y does what?
locks in transcription state
51
Parthenogenesis (def.)
A form of reproduction where the egg develops into an embryo without being fertilized by a sperm. Derived from the Greek words for “virgin birth”
52
Embryoid bodies are _____ that can ______
-3D aggregates of pluripotent stem cells
-differentiate into cells of all three germ layers
53
There appears to be significant functional differences between_______ with males having _____ and females having ______
-human adult germinal stem cells in each sex
-constantly regenerating stem cell population (spermatogonia)
-a limited number of partially differentiated oocytes (follicles)
54
methods for studying human cell diversity
-flat (2D) cell culture
-lab animals
-organoids (3D)
55
types of lab animals
-simple (flies)
-complex (mouse)
56
easiest human cell to culture in lab
fibroblasts
57
passage number of cell culture (def.)
the number of times it has been subcultured (creating multiple daughter cell culture flask)
58
immortalization (def.)
cells from multicellular organisms which won't normally not proliferate indefinitely but due to mutations, they have lost senescence and keep undergoing division
59
primary cells (general def.)
normal cells directly from humans or animals
60
immortalized cell lines (general def.)
cancer (transformed) cells derived from humans or animals
61
immortalized cell lines are comprised of _____
a single cell type (homogenous) that can divide indefinitely
62
immortalized cell lines are usually ____ and maintain _____
-diploid
-some degree of differentiation
63
transformed cell lines have almost ____ but the disadvantage is that _____
-availability
-it retains less of the in vivo characteristics
64
primary cell lines are derived from ______
excised tissue
65
primary cultures are initially _____ by eventually become dominated by ______
-heterozygous
-fibroblasts
66
primary culture lifespan
limited
67
primary cells usually retain _____
many differentiated characteristics that the cells had in vivo
68
stem cells are more difficult to _____
culture
69
stem cells have the unique ability to ______
self-renew or to differentiate into various cell types in response to appropriate signals
70
working with human cell cultures requires ______
aseptic environment
71
primary cells will require growth on _____ to promote ______
-special matrixes such as collagen
-cell attachment, differentiation or cell growth
72
passaging cells
-cells should be split more than 1:10 so seeding density will not be too low
73
increasing passage number = ____
genetic drift and other variations
74
anything inside biosafety cabinet must be _____
sanitized
75
inorganic salts in culture medium do what?
maintain osmotic balance of cells and regulate membrane potential
76
buffering systems in culture medium do what?
-main pH conditions in 7.2 - 7.4 (indicated by phenol red colour)
77
carbohydrates in culture medium do what?
main source of energy generally in form of sugars
78
vitamins in culture medium?
-riboflavin, thiamine and biotin
79
trace elements in culture medium?
-zinc, copper and selenium
80
FBS stands for ____
Fetal bovine serum
81
FBS is used for ____
in-vitro cell culture of eukaryotic cells
82
FBS is complex mix of ____
albumins, growth factors and growth inhibitors
83
Normal cells stop proliferating once _____ but cancer cells do what?
-they have proliferated into a single layer
-often disregard these restraints and continue to pile on each other
84
proliferation depends on contact with dish and is inhibited by _____
contacts with other cells
85
confluency (def.)
the percentage of the surface of a culture dish covered by cells
86
confluency is important because _____
cells change their behaviour with changing densities
87
low-density cells usually grow _____
slower than 50% confluent cells
88
If plate is completely confluent, cells ___
tend to grow slower
89
changes of growth rate will influence _____
their genetic programming and behaviour in experiments
90
steps to establish primary cell culture
1) tissue acquisition
2) dissection (remove dead + fatty tissue)
3) disaggregation (break ECM)
4) incubation & growth
5) separation & purification by selective media, immunomagnetic beads
91
Hayflick limit (def.)
represents the number of times a normal human cell pop'n will divide before cell division stops (senescence)
92
telomere length is considered ____
the molecular timer for the number of times a human cell can divide
93
hayflick limit of stem cells vs. cancer cells
-stem cells: 50-70
-cancer cells: avoid telomere shortening
94
telomere length is a key contributor to _____
the deleterious effects of aging process in humans
95
ways to overcome Hayflick limit
-tumor derived cells (inefficient)
-viral gene simian virus 40 T-antigen infected cells (ex. Hek293T)
-human Telomerase reverse transcriptase (hTERT) protein: makes telomeres longer
96
advantages of hTERT immortalization
-normal cell cycle controls
-contact inhibited
-interact with substrates
-retain normal growth responses to serum & mitogens
-normal karyotype
97
source of human embryonic stem cells (hESCs)
-fertilized human embryos
98
use of hESCs are dropped in recent years with _____
increased availability of iPSCs
99
3D cell culture niche
ECM, cell-cell contact, O2 and nutrients
100
3D cell culture is often performed in ____
suspension rather than in plastic dishes
101
3D cell organization happens using ____
molecular scaffolds (natural biomaterials or synthetic polymers)
102
organoids can be made from _____
adult SC, or PSC
103
organoids (def.)
small organ-like structures from human cells
104
KSR
-knockout serum replacements
105
matrigel (def.)
a 3D scaffold
106
activin A (def.)
part of the TGFB protein family but acts to promote proliferation instead of inhibits
107
minimal media (def.)
salts, nutrients only no serum
108
the diffusion limit (def.)
organoids do not have a vasculature so cells in the center become starved for O2 and nutrients
109
guided differentiation
provision of signalling molecules at correct time and place to mirror what happens during normal development
110
organizers (def.)
local sources of morphogens
