FINAL Flashcards
stages of mammary development
mammogenesis = mammary epithelial cell (MEC) proliferation
- stimulated by estrogen (+ GH + IGF-1)
- ductal elongation
- throughout puberty
- fluctuation of progesterone influences alveolar development
lactogensis = ductal development & differentiation of MEC into alveolar cells capable of synthesizing & secreting milk
- initiation of lactation
- late pregnancy milk production
- inititated by rising estrogen, prolactin, GH, & placental lactogen
galactopoiesis = lactation
- parturition ➔ weaning
- stimulus = emptying of milk & sucking
involution = apoptosis of MEC & regression of mammary gland
udder tissue
supramammary lymph node
parenchyma = glandular secretory tissue
gland cistern = milk storage once its made
teat cistern = milk storage
furstenberg’s rosette = mucosal folding that folds over the streak canal as barrier → protection from bacteria/infx
streak canal = channel ate bottom of teat where milk exits
mammary epithelial cells (MEC) in single layer lining lumen (central cavity) = secretory tissue
myoepithelial cells contract when oxytocin is present (muscular)
alveoli form during pregnancy when progesterone causes full differentiation
estrogen influence on mammary development
stimulates duct & cistern development
- during follicular phase of estrous cycle
- replaces fat w/ branches
- lengthening of branches & ducts
progesterone influence on mammary development
induces formation of alveoli
- present in luteal phase
- causes duct cells to widen & converts terminal end buds to alveoli
- complete alveoli development when CL stays (if pregnant/fertilized)
- helps prevent contractions & induces mammary development
during estrous cycle
estrogen made in ovary in granulosa cells during follicular phase
progesterone made in ovary in CL during luteal phase
dominance
interactions btwn alleles at same loci
epistasis
interactions btwn alleles at diff loci
epigenetic
changes in phenotype based on envir (not DNA sequence)
additive variance
genes cause traits ➔ predictable
non-additive variance
indiv allele combinations (&/or envir) influence traits (transmission harder to predict)
heritibility
ratio of phenotype to genotype
stadard deviation
how far each value lies from the mean
selection differential
the diff btwn avg of pop & avg of selected indiv
- can made predictions about future gen
- can identify superior/inferior indiv
quantitative loci map
identifies regions of genome w/ statistical significance to desired trait
- marker assisted selection
-
genome wide assisted selection
- SNP = single nucleotide polymorphism
-
SNP chip = high capacity phenotyping
- profile of a bull can be evaluated & correlated w/ phenotype of progeny
- selective breeding tool
breeding value
additive genetic variance
biotech used in AG
ART = assisted reproductive tech
- AI
- estrous synchronization (progesterone to block FSH & LH for ~2w so everyone will come into heat when stopped
-
superovultion: Oocytes collected from ovaries after slaughter or by ovum pickup following superovulation matured and fertilized in vitro (IVF)
➔ Resulting embryos transferred immediately or following culture
dx, vs, rx
selective breeding
gene editing
genetic engineering
DNA in dx
nucleic acid based: detecting pathogen based on DNA/RNA sequence
- PCR = polymerase chain rxns to amplify nucleic material in vitro ➔ use that DNA sequence to identify pathogen
- protein antibodies can be detected
- tradiional methods (eg microscopy, culture, biochemical characteristics)
- genetic diseases
- traits
uses of recombinant DNA
making DNA mol in lab by joining pieces together
- RX
- VX
- distemper
- parvo
- coronavirus
- kennel cough
- rabies
- FLV
- lyme
- rinderpest (first to be erraticated)
- salmonella
- pseudorabies virus
- can be put in fish feed & spread so wild pop is vx
methods to make transgenic animals
pronuclear microinjection: collect 1-cell zygotes via superovulation or estrous synchronization & inject transgene = piece of DNA containing coding & regulatory elements (aka DNA construct) via IVF
- allows gene addition only
- DNA inserts randomly in genome
- low efficiency
SCNT-based cloning: introduce DNA to cells prior to cloning
- fusion of a donor cell to an enucleated unfertilized egg or early embryo
- chemical or electrical current to trigger embryo to divide as if fertilized
- enable site-specific modifications w/ low efficiency but all animals are born transgenic
gene editing tools
- DNA binding proteins using engineered nucleases
- complex of nuclease & RNA: CRISPR-Cas9 = clustered regularly interspaced short palindromic repeats (CRISPR-Cas9) uses elements of a bacterial defense system that guide complementary RNA to site in genome they want to cut
- repair pathways
- introduce targeted, double-strand break in DNA for cell to repair using non-homologous end joining (NHEJ) but mistakes in repair ➔ indels (small insertions & deletions) that make DNA non-functional
- homology directed repair (HDR) ➞ looks at pieces on end that match target site & replaces with new/changed DNA
how can genetic engineering/gene editing be used in animals
-
↑ growth: GE Salmon with ↑ growth rates
- ↓ production footprint
- better utilization of feed (digestion & absorption)
- more efficient at converting feed into body mass
- reach market weight twice as fast
- can grow year round
-
↓ environmental pollution
- pigs need P → all feed has phytate (good source of P) but cannot break down in GI so need supplementation → a lot of P comes out in manure = bad for envir
- transgenic pigs express transgene in saliva of parotid gland so they can digest phosphorus & produce 75% less P in their manure
-
↓ heat stress
- editing to produce SLICK cattle → less hair
- color dilution phenotype → lighter coat attracts less heat
- ↑ disease resistance
- treat diarrha in children under 5 via SI villi & absorption
- pharmaceuticals
- pigs as medical models
- xenotransplantation
- change food composition
-
antimicrobial proteins ➔ treat & prevent diarrhea
- malnourishment damages intestinal villii
- cannot absorb nutrients
sertoli cells
supportive cells ➞ aid in the formation of sperm
- force spermatogonium in 1 direction towards lumen
- guarding & directionality
Leydig cells
produce testosterone in interstitial space btwn seminiferous tubules
accessory sex glands
addition of fluid, nutrients, & butters so sperm can be motile & help survive inside egg
- bulbourethral gland flushes out urine & sperm
- prostate: sperm motility
- seminal vesicle secretes buffers, sugars, & vit to help sperm survive
-
ampulla: where sperm is stored right before ejaculation
- widening of vas deferens
- only bulls
sigmoid flexure
“S” shaped configuration penis except during copulation
bulbourethral gland
flushes out urine & sperm
- sedondary sex characteristic
prostate
sperm motility
- sedondary sex characteristic
seminal vesicle
secretes buffers, sugars, & vit to help sperm survive
- secondary sex characteristic
ampulla
where sperm is stored right before ejaculation
- widening of vas deferens
- only bulls
- secondary sex characteristic
duplex uterus
2 cervices + uterine horns
- marsupials
- rabbits
bicornuate uterus
1 cervix + uterine horns
- poorly to moderately developed: mare & cow
- highly developed: dog, queen, sow
oviduct in birds
- infundibulum ➞ fertilized
- magnum ➞ albumen (egg white) is added to egg
- isthmus ➞ shell membrane is put on egg ➞ protection against bacteria & moisture
- shell gland ➞ shell is formed & pigmented
SI
- duodenum: neutralizes stomach acid & majority of enzymatic digestion
- peristalsis mixes feed & enzymes & moves down GI tract
- point of entry for digestive enzymes from pancreas + bile from gallbladder
- jejunum: digestion & absorption
- ileum: absorption of AA, sugars, & fatty acids
LI
absorption & elimination
- colon: water absorption & drying
- cecum: blind pouch (important for hind-gut fermenters)
- rectum: connects colon to anus
liver
processes, metabolizes, filters, & sorts nutrients
- makes bile = water, salts, cholesterol, pigments ➞ emulsifies fat & keeps in soln
gallbladder
secretes bile into duodenum to assist w/ lipid absorption
- stores & concentrates bile until needed
pancreas
secretes digestive enzymes
rumen
arge compartment full of 80% microbes (yeast, protozoa, bact) secrete enzymes that break down cellulose
- lined with papillae: small projections that ↑ SA ∴ ↑ absorption
reticulum
catches large particles not broken down by rumen microbes
- honeycomb inner surface
omasum
hard ball of dried & condensed feed
- many folds inner surface
abomasum
digestion, acid secretion, starts chemical breakdown, storage
- “true stomach”
- smooth inner surface
mucous neck cells
secrete mucus ➞ prevents degradation of proteins/nutrients by acid
parietal cells
secrete HCl & intrinsic factor
chief cells
secrete enzymes
- pepsinogen
- rennin
- gastric lipase
- polyestrous
- 21 day cycle
- d1: ovulation
- d2-4: developing CL
- d5-15: mature CL
- d16-20: regressing CL
- d21 or 0: estrus
follicle stimulating hormone (FSH)
- M: stimulates sertoli cells in testis to produce sperm
- F: induces follicle growth in ovary
- acts on granulosa cells
luteinizing hormone (LH)
- M: stimulates testosterone production by leydig cells in testes
- F: stimulates estrogen production in ovary & ovulation
- acts on theca cells
estrogen
produced by granulosa cells
- helps w/ development & fx of reprod tract & important when F is in heat/ready to breed ➞ drives B that can signal to prod
- early on: inhibits (- feedback) LH & FSH
- later: + feedback later on → LH surge
progesterone
made by CL ➞ maintain pregnancy
- prepare uterus to for egg implantation
- keeps uterine envir optimal for egg
- prevents uterus from contracting & expelling egg
- blocks FSH & LH
prostaglandin
regression & breakdown of CL if no fertilization
- luteolysis → CL regresses
- progesterone levels drop → progesterone block released → LH & FSH ↑
- new follicles can grow
- key mediator if pregnancy does not occur
luteal phase
has CL ➞ ↑ progesterone
- longest phase
- metestrus: CL is forming
- diestrus: CL is mature
follicular phase
follicles are growing & egg is maturing
- proestrus: time btwn CL breakdown & heat
- progesterone levels ↓
- growth of follicle = ↑ estrogen & LH leading up to estrus
- estrus: animal is receptive to breeding ➞ in heat
- estrogen level peaks & right before LH surge
- ↑ estrogen levels cause B signs
oogenesis
total digestible nutrients (TDN)
energy (E) value of feed
digestible energy (DE)
feed that can be broken down by animal (animal can use)
metabolizable energy (ME)
energy available to use
- ME = digestible energy - E in urine & gaseous byproducts of digestion
net energy (NE)
amount of energy left for animal to partition for 1. maintenance & 2. production
