Mammalian lung develops as an evagination of ventral gut endoderm into the underlying mesenchyme. Iterative epithelial branching, regulated by the surrounding mesenchyme, generates an elaborate network of airways from the initial lung bud. Fibroblast growth factors (FGFs) often mediate epithelial-mesenchymal interactions and mesenchymal Fgf10 is essential for epithelial branching in the develop...

The teratogen nitrofen produces a congenital diaphragmatic hernia (CDH) and pulmonary hypoplasia in rodent fetuses that closely parallel observations made in humans. We hypothesized that these changes may be due to primary pulmonary hypoplasia and not herniation of the abdominal contents. Timed-pregnant rats were given nitrofen on day 9, and fetuses were harvested on days 13 through 21. Initial...

During Xenopus development, p120 transcripts are enriched in highly morphogenetic tissues. We addressed the developmental function of p120 by knockdown experiments and by expressing E-cadherin mutants unable to bind p120. This resulted in defective eye formation and provoked malformations in the craniofacial cartilage structures, derivatives of the cranial neural crest cells. Closer inspection ...

The vertebrate eye develops from the neuroepithelium of the ventral forebrain by the evagination and formation of the optic vesicle. Classical embryological studies have shown that the surrounding extraocular tissues - the surface ectoderm and extraocular mesenchyme - are necessary for normal eye growth and differentiation. We have used explant cultures of chick optic vesicles to study the regu...

When stationary phase cells of the dimorphic yeast Candida albicans are diluted into fresh medium at pH 4.5 (low pH), they synchronously form ellipsoidal buds, but when diluted into the same medium at pH 6.7 (high pH), they synchronously form elongate mycelia. Using a perfusion chamber to monitor single cells, we have compared the rates of volume growth between budding and mycelium-forming cell...

MicroRNAs (miRNAs) are small (20-22 nt), non-coding RNAs involved in post-transcriptional gene silencing. Their binding to the 3' UTR of target mRNAs influences the translation or stability of the transcripts. miRNAs have been shown to regulate several developmental and physiological processes, including stem cell differentiation and the immune response. Recent findings report their involvement...

Developmental anomalies affecting number, size, shape, structure, and location of teeth are varied. One such rare anomaly affecting the shape of anterior teeth is talon cusp. It is an accessory cusp-like projection found on lingual or labial surfaces of the upper or lower incisors, unilaterally or bilaterally in both dentitions. It is composed of normal enamel and dentine, with or without pulp....

The actual spatial geometry of separate regions of normal and enlarged fenestrations from the internal elastic lamina of human cerebral arteries have been replicated in sheets of latex rubber from scanning electron microscope (SEM) photomicrographs. Geometrical models which assume a constant diameter for the fenestrations, a constant ligament efficiency for the regions of fenestrations and a un...

The morphogenesis of vertebrate body parts remains an open question. It is not clear whether the existence of different structures, such as a head, can be addressed by fundamental laws of tissue movement and deformation, or whether they are only a sequence of stop-and-go genetic instructions. I have filmed by time-lapse microscopy the formation of the presumptive head territory in chicken embry...

In vertebrates, retinal progenitor cells (RPCs) are specified at the end of the gastrulation within the anterior neural plate (ANP) as a single domain called the eye field. From that single domain, positioned medially within the ANP, the RPCs give rise to two optic vesicles, positioned more laterally. How this dramatic morphogenetic remodelling occurs is not well understood. We will show that s...