Proteolytically Degraded Alginate Hydrogels and Hydrophobic Microbioreactors for Porcine Oocyte Encapsulation

Molecular Mechanism and Application of Somatic Cell Cloning in Mammals

“…After its intraooplasmic microinjection, the karyoplast may also be a source of mitochondria (mitochondrial genome) of heteroplasmic origin. Therefore, a reconstructed cloned embryo, which from a cytological viewpoint is a cytoplasmic hybrid (cybrid), harbors the mitochondrial genome of both maternal (oocyte's) and exogenous origin (i.e., introduced together with the nuclear donor cell) [107,111,[160][161][162]. In cloned embryos, fetuses, and offspring, mitochondria are primarily inherited with ooplasmic material.…”

“…Moreover, the presence of an oocyte-derived mitochondrial genetic apparatus has been shown to influence the implantation of cloned embryos in the endometrium of a recipient female's uteri. For that reason, the deleterious effect, on the preimplantation development of cloned embryos, of heterogeneous mtDNA sources as a result of possible mitochondrial heteroplasmy in the reconstructed nuclear-cytoplasmic hybrids should not be discounted [139,160,161,169]. That is why the production of nuclear-transferred embryos, fetuses, and offspring with a precisely defined profile of nucleotide sequences in regulatory or coding segments of the nuclear and/or mitochondrial genome seems to be valuable tool.…”

“…Such cloned offspring exhibits a degree of variation/incompatibility with regard to phenotypic traits determined by cytoplasmic (extranuclear) inheritance. The latter is dependent on the mitochondrial genotype known as the mitotype [105,157,159,160,167].…”

“…This type of leukocyte-erythroblast chimerism results both from mtDNA heteroplasmy in peripheral blood cells and from genetic mosaicism within subpopulations of nucleated hematopoietic cells (i.e., hematopoietic karyocytes). Such chimerism may also have a certain effect on differences in the mitotype of cloned progeny [139,160,165,169].…”

“…The procedure of IVM was performed according to the technique described by Pedersen et al [159]. The group of COCs intended for IVM were encapsulated in fibrin-alginate hydrogel beads (FABs) according to a previously reported protocol [160]. In detail, a subpopulation ranging from 3 to 5 COCs along with a minimum volume (up to 5 µL) of maturation medium were precisely transferred (with the use of micropipette) into a drop of mixture of fibrinogen and alginate (FA: 0.5% alginate solution and 50 mg/mL fibrinogen solution mixed in a 1:1 ratio; Sigma-Aldrich).…”