The present invention provides modified oocytes having a nuclear genome derived from a first oocyte and cytoplasm derived from a second oocyte from a different subject, and methods for making and using such modified oocytes. The methods and compositions of the present invention can be useful in a variety of settings including, but not limited to, in in vitro fertilization (IVF) procedures.

Oogonial stem cell (OSC)-derived compositions, such as nuclear free cytoplasm or isolated mitochondria, and uses of OSC-derived compositions in autologous fertility-enhancing procedures are described.

Methods are provided of generating functional human oocytes following nuclear transfer of first polar body (PB1) genomes from metaphase II (MII) oocytes into enucleated donor MII cytoplasm (PBNT) and using mitochondrial replacement techniques to circumvent mother-to-child mtDNA disease transmission.

Methods for producing stem cell banks, preferably human, which optionally may be transgenic, e.g., comprised of homozygous MHC allele cell lines are provided. These cells are produced preferably from parthenogenic, IVF, or same-species or cross-species nuclear transfer embryos or by de-differentiation of somatic cells by cytoplasm transfer. Methods for using these stem cell banks for producing stem and differentiated cells for therapy, especially acute therapies, and for screening for drugs for disease treatment are also provided.

The present invention provides modified oocytes having a nuclear genome derived from a first oocyte and cytoplasm derived from a second oocyte from a different subject, and methods for making and using such modified oocytes. The methods and compositions of the present invention can be useful in a variety of settings including, but not limited to, in in vitro fertilization (IVF) procedures.

An embryo, gamete or stem cell culture medium comprising: a) acetyl-carnitine at a concentration of about 5 to about 50 M; and b) lipoic acid or a derivative thereof at a concentration of about 2.5 to about 40 M. The culture medium may optionally further comprises acetyl-cysteine at a concentration of about 5 to about 50 M.

Methods for improving the functionality and/or fertility of sperm, for example, by enhancing motility and/or extending the lifespan of sperm by subjecting the isolated sperm to a starvation protocol and/or ionophore are provided. Such methods may be used in, for example, artificial insemination to reduce the number of sperm needed for insemination and to improve conception rates.

The present invention provides novel methods for improving the efficiency of artificial activation of unfertilized mammalian oocytes by reducing the intracellular concentration of Zn.sup.2+ in the oocyte. The methods of the invention may additionally comprise a preceding step of increasing the intracellular concentration of Ca.sup.2+ in the oocyte prior to reduction of the intracellular Zn.sup.2+ concentration. The invention further provides unfertilized oocytes activated by the disclosed methods and viable mammalian animals produced from unfertilized oocytes activated by the disclosed methods.

In vivo methods using bioenergetic agents for restoring the quality of aged oocytes, enhancing oogonial stem cells or improving derivatives thereof (e.g., cytoplasm or isolated mitochondria) for use in fertility-enhancing procedures, are described.

The present invention relates to a method of culturing an embryo for implantation, the method comprising: incubating a pre-compaction stage embryo in a first embryo culture medium; adding a second medium to the first embryo culture medium to form a compounded embryo culture medium; and further incubating the embryo in the compounded embryo culture medium for implantation.