Speciation in animals commonly involves an extrinsic barrier to genetic exchange followed by the accumulation of sufficient genetic variation to impede subsequent productive interbreeding. All-female species of whiptail lizards, which originated by interspecific hybridization between sexual progenitors, are an exception to this rule. Here, the arising species instantaneously acquires a novel ge...

Three new species of Fergusobia, respectively collected from shoot bud galls on narrow-leaved Melaleuca spp. in Australia, are described. Fergusobia armillarisae n. sp. Davies is characterised by the combination of an arcuate to open C-shaped parthenogenetic female with an extensile uterus and a short, conoid tail, an arcuate infective female with a broadly rounded tail tip, and an arcuate male...

Parthenogenetic embryos of mice die shortly after implantation and characteristically contain poorly developed extraembryonic tissue. To investigate the basis of the abnormal development of parthenotes, we combined them with normal embryos to produce chimeras and examined the distribution of the parthenogenetically derived cells during preimplantation and early postimplantation development. The...

Asexuality frequently evolves in association with hybridity and polyploidy. The phenotypic consequences of this association must be understood before we can fully appreciate the reason for the short-term success, and the long-term failure, of asexual genetic systems. Parthenogenetic forms within the Australian gecko complex Heteronotia binoei are triploid hybrids and overlap geographically with...

OBJECTIVE To compare directly in vitro developmental competence between parthenogenetically activated and intracytoplasmic sperm injection (ICSI)-fertilized oocytes. DESIGN For each patient, three metaphase II oocytes were randomized to the ICSI procedure, while n-3 were allocated to parthenogenetic activation. SETTING University hospital infertility unit. PATIENTS Thirty-eight patients, ...

Parthenogenetic embryos, which contained one genome from a neonate-derived non-growing oocyte and the other from a fully grown oocyte, developed to day 13.5 of gestation in mice, 3 days longer than previously recorded for parthenogenetic development. To investigate the hypothesis that disruption of primary imprinting during oocyte growth leads to the modified expression of imprinted genes and t...

The identity and functional potential of dopamine neurons derived in vitro from embryonic stem cells are critical for the development of a stem cell-based replacement therapy for Parkinson's disease. Using a parthenogenetic primate embryonic stem cell line, we have generated dopamine neurons that display persistent expression of midbrain regional and cell-specific transcription factors, which e...

Strain LT/Sv female mice show a high frequency of spontaneous ovarian teratomas arising from parthenogenetically activated follicular oocytes. LT/Sv oocytes also arrest at metaphase of meiosis I, rather than progressing through to metaphase II, as do almost all fully grown oocytes from most other strains. We investigated a new set of recombinant inbred strains derived from BALB/c and C58 (the p...

Parthenogenetic embryonic stem cells (PgES) might advance cell replacement therapies and provide a valuable in vitro model system to study the genomic imprinting. However, the differential potential of PgES cells was limited. It could result from relative low heterology of PgES cells compared with ES cells from fertilization (fES), which produce different expression of most imprinted genes. Her...