Early Mammalian Development: Parthenogenetic Studies

The early development of haploid and aneuploid parthenogenetic embryos.

The early development of parthenogenetically activated oocytes had been studied in C57BL X CBA-T6T6 (F1T6) translocation heterozygote mice and C57BL X CBA-LAC (F1LAC) mice. All F1T6 oocytes had either a quadrivalent or a univalent-trivalent configuration at meiosis I; no such chromosome configurations were observed in the F1LAC oocytes. At ovulation 36-5% of the F1T6 oocytes had 19 or 21 chromo...

DNA methylation in early mammalian development

Epigenetic mechanisms in early mammalian development.

begins well before fertilization because the molecules and controlling mechanisms that direct early development are put in place during oogenesis. The informational content of a mammalian egg at fertilization is not only restricted to its DNA sequence, but also to various DNA and chromatin modifications, specific macromolecules (RNAs and proteins), and possibly the characteristic architecture o...

Development before and after cryopreservation of porcine parthenogenetic embryos derived from early-delipated oocytes

The cryopreservation of mammalian oocytes and embryos has application to preserve genetic diversity and for in vitro fertilization protocols in humans. To date, cryopreservation techniques have been used in a variety of species, including rabbits [1, 2], cattle [3, 4], horses [5, 6], cats [7, 8], mice [9, 10] and ferrets [11], among others. However, because of the biological uniqueness of porci...

The chromosomes of turkey embryos during early stages of parthenogenetic development.

In the early stages of parthenogenetic development in turkey eggs, many blastoderms are mosaics of haploid, diploid and polyploid cells. The genome composition of these blastoderms can be identified by C-banding. They may be generally described as either A-Z/2A-ZZ/nA-nZ or A-W/2A-WW/nA-nW and are found in a nearly 1:1 ratio. The blastoderms showing the W body (W+) become lethal within two days ...