On the basis of 3 personal cases and 119 additional cases collected from the literature the difference between dextroversion and mirror-image dextrocardia is outlined. It is concluded that dextroversion is a part of an exceedingly primitive arrest in development that frequently includes other thoracic and abdominal organs as well as intracardiac structures. The defect is altogether different in...

Recent advances have given us new insights into the molecular basis of organ position. A gene cascade that determines left-right positioning of organ primordia has emerged. In here we present the current knowledge of the molecular determinants of organ positioning during vertebrate embryogenesis.

A recent publication identifies npas4l as the gene defective in the well-known cloche mutant that lacks most endothelial as well as hematopoietic cells. This work poses intriguing questions as to the genetic and molecular nature of the origin of hemato-vascular lineages during early embryogenesis.

Wnt signaling is crucial for embryonic development in all animal species studied to date. The interaction between Wnt proteins and cell surface receptors can result in a variety of intracellular responses. A key remaining question is how these specific responses take shape in the context of a complex, multicellular organism. Recent studies suggest that we have to revise some of our most basic i...

In cell divisions, relative size of daughter cells should play fundamental roles in gametogenesis and embryogenesis. Differences in gamete size between the two mating types underlie sexual selection. Size of daughter cells is a key factor to regulate cell divisions during cleavage. In cleavage, the form of cell divisions (equal/unequal in size) determines the developmental fate of each blastome...

Vitamin A insufficiency has profound adverse effects on embryonic development. Major advances in understanding the role of vitamin A in vertebrate heart formation have been made since the discovery that the vitamin A active form, all-trans-retinoic acid, regulates many genes, including developmental genes. Among the experimental models used, the vitamin A-deficient avian embryo has been an impo...

background: since embryonic stem (es) cells have the dual ability to proliferate indefinitely and differentiate into multiple tissue types, es cells could potentially provide an unlimited cell supply for human transplantation. objective: in order to study the differentiation of mouse embryonic stem (mes) cells, they were cultured in suspension by using es media without leukemia inhibitory facto...