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Stem Cells
Question | Answer |
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Brockes & Kumar 2005 | Review: Blastema from salamander amputated limb remains a memory of where it is from and will regenerate as an arm. Prod1 gene is expressed in a gradient along the arm. Retinoic acid makes the blastema think it is more proximal. |
Spalding et al 2005 | Uses 14C carbon residue from nuclear testing to gauge the extent of neurogenesis. Same approach has been used for several tissues |
Ming & Song 2011 | Review: BrdU has been a valuable tool in understanding stem cells. Brain damage appears to incr rate of neurogenesis although chronic damage, such as diabetes, overwhelms this. Neurogenesis probably of limited physiological value (my opinion not author's) |
Veeraraghavalu et al 2010 | Mutations in presenilin1 incr probability of cells becoming neurons, less likely to enter other pathways. Isolated cells were poor at forming neurospheres, indicating failure to maintain the stem cell niche. y secretase cleaves notch etc (dev proteins) |
Gurdon 1962 (only author) | Created cloned frogs (many fertile) using implantation of somatic nuclei into enucleated cells. 1% efficacy so people thought he had contaminating cells |
Wilmut et al 1997 | Produced Dolly the sheep using a mammary gland cell nucleus from an adult sheep. This showed that genetic material had not been lost. |
Yamanaka & Blau 2010 | Review: Nuclei taken from dividing cells, reprogramming factors in cytoplasm (why is that good?). Reversal of X inactivation os a key marker of de-differentiation. |
Harris et al 1969 | Showed non-malignant cells reduced malignancy of a cancer line when fused together. Early indication of tumour suppressor genes. Used sendai virus to fuse, has been used to make mouse hybridomas for antibody therapy. Dont see controls (norm/norm, etc) |
Takahashi & Yamanaka 2006 | Tested 24 factors known to be required in embryonic stem cells (ESCs), pluripotence marker was tied to neomycin resistance to show success. Found sox2, oct4, klf4 & c-myc. Injection of cells formed teratomas. DNA microarrays showed v. similar to ESCs |
Kucharski et al 2008 | Using siRNA to knockdown Dnmt mimicked the ingestion of royal jelly, caused larvae to become queen bees rather than workers. These effects corresponded with reduced DNA methylation at several tested sites. |
Palmer et al 2000 | Showed association between neurogenesis and fine capillaries. Labelled cells with BrdU. Dividing neuronal cells often found with dividing capillaries. A factor from the latter may stimulate the former which could explain neurogenesis after exercise. |
Van Praag et al 1999 | Running incr neuronal proliferation in the dentate gyrus of hippocampus (as labelled by BrdU). Exercise has to be voluntary (no improvement in forced swim). No gain in mice given learning tasks (water maze). Social interaction group may also have gains. |
Evans & Kaufman 1981 | Isolated pluripotent cells from a diapausing blastocyst. This was the first time a cell line had been created without extracting the cells from a teratoma. (in cambridge) |
Ptak et al 2012 | Species which dont normally enter diapause (sheep) can be induced to diapause by tranfer of the embryo into a mouse uterus. Shows that mammalian embryos have the capacity to diapause even if they dont usually, would be good to know what factors allow this |
Marchetto et al 2010 | Used induced pluripotency to turn back the clock on Rett syndrome. Allowed them to study neuronal growth in culture and also test IGF-1 on a valid cell line to see if it rescued the phenotype, appeared to help. |
Brennand et al 2011 | Took fibroblasts from schizophrenics, reprogrammed to neurons and showed reduced connectivity. This was improved by loxapine (although not clozapine, risperidone & others). Used lentivirus to reprogram. |
Ellison et al 2011 | Used IGF1 and HGF in combination to activate cardiac stem cells and increase proliferation after myocardial infarct. Effect was dose dependent. Used BrdU to show dividing cells and quantify improvement. |
Davis et al 1997 | Transfection of MyoD into fibroblasts caused them to become myoblasts without passing through the IPSC stage. Used Moloney sarcoma virus to transfect. Occured in under a week |
Zhou et al 2008 | Exocrine cells in the pancreas can be converted into beta cells (insulin +ve). Used adenoviral transfection (prefers quiescent cells and tends to infect exocrine). ngn3, pdx1 and mafa were transfected. Direct reprogramming |