Search results
Results from the WOW.Com Content Network
The genetically modified mouse in which a gene affecting hair growth has been knocked out (left) shown next to a normal lab mouse. A genetically modified mouse, genetically engineered mouse model (GEMM) [1] or transgenic mouse is a mouse (Mus musculus) that has had its genome altered through the use of genetic engineering techniques.
The mutation frequency of female germline cells in mice is about 5-fold lower than that of somatic cells, according to one study. [13] The mouse oocyte in the dictyate (prolonged diplotene) stage of meiosis actively repairs DNA damage, whereas DNA repair was not detected in the pre-dictyate (leptotene, zygotene and pachytene) stages of meiosis ...
In the mouse, by days 6.25 to 7.25 after fertilization of an egg by a sperm, cells in the embryo are set aside as primordial germ cells (PGCs). These PGCs will later give rise to germline sperm cells or egg cells. At this point the PGCs have high typical levels of methylation.
PGC-like cells generated using this method can be transplanted into a gonad, where the differentiate, and are able to give viable gametes and offspring in vivo. [34] PGC-like cells can also be generated from naïve embryonic stem cells (ESCs) that are cultured for two days in the presence of FGF and Activin-A to adopt an epiblast-like state.
The existence of oogonial stem cells in mammals is controversial, [7] except for the finding of OSCs in two species of loris [8] [9] and three species of bat. [10] In 2004, considerable evidence was provided for the existence of germline stem cells in adult mouse ovaries capable of generating oocytes to form new follicles.
A germline mutation, or germinal mutation, is any detectable variation within germ cells (cells that, when fully developed, become sperm and ova). [1] Mutations in these cells are the only mutations that can be passed on to offspring, when either a mutated sperm or oocyte come together to form a zygote . [ 2 ]
The embryonic stem cells that incorporated the knocked-out gene are isolated from the unaltered cells using the marker gene from step 1. For example, the unaltered cells can be killed using a toxic agent to which the altered cells are resistant. The knocked-out embryonic stem cells from step 4 are inserted into a mouse blastocyst. For this ...
In addition, stem cell are undifferentiated cells which can develop into a specialized cell and are the earliest type of cell in a cell lineage. [2] Due to the differentiation in function, somatic cells are found only in multicellular organisms, as in unicellular ones the purposes of somatic and germ cells are consolidated in one cell.