BACKGROUND Failed fertilization after IVF occurs in 10-20% of cycles. Conflicting results of rescue fertilization by ICSI have been reported. We therefore compared the success rate in terms of fertilization and pregnancy of cycles in which rescue ICSI was performed with those from a matched control group of primarily ICSI cycles. METHODS Unfertilized oocytes from IVF cycles with total fertili...

Members of the orthodenticle gene family are essential for embryonic brain development in animals as diverse as insects and mammals. In Drosophila, mutational inactivation of the orthodenticle gene results in deletions in anterior parts of the embryonic brain and in defects in the ventral nerve cord. In the mouse, targeted elimination of the homologous Otx2 or Otx1 genes causes defects in foreb...

In the Drosophila embryo, a subset of muscles require expression and function of the RYK subfamily RTK gene derailed (drl) for correct attachment. We have isolated a second RYK homolog, doughnut (dnt), from Drosophila. The DNT protein exhibits 60% amino acid identity to DRL, and is structurally as similar to the mammalian RYK proteins as is DRL, indicating an ancient duplication event. dnt is e...

Hybrids (2n = 3x = 21) between Aegilops ovata and Secale cereale were produced via embryo rescue. Most hybrid morphological traits were intremediate between parents, the plants grew vigorously but were completely sterile. The average frequency of chromosome associations at metaphase I was 19.57-20.19 univalents and 0.40-0.86 rod bivalents. The fertility of the hybrids was restored by doubling t...

The Drosophila embryonic salivary gland is a migrating tissue that undergoes a stereotypic pattern of migration into the embryo. We demonstrate that the migratory path of the salivary gland requires the PDGF/VEGF pathway. The PDGF/VEGF receptor, Pvr, is strongly expressed in the salivary glands, and Pvr mutations cause abnormal ventral curving of the glands, suggesting that Pvr is involved in g...

In the mouse embryo, gap junctions first appear at the 8-cell stage as compaction is about to take place. Compaction of the embryo is important for the differentiation of the first two cell types; the inner cell mass and the trophectoderm. Our studies examine the contribution of gap junctional communication at this stage of development. We have characterised the normal sequence of appearance of...