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
