UNSW Embryology

Bat - not a typical embryo used in developmental studies, but first alphabetically and an alternative mammalian model. A recent paper has detailed the short-tailed fruit bat (Carollia perspicillata) embryonic stages of development.

Bovine - not a typical embryological model, but extensively studied due to commercial value and more recently for breeding using IVF techniques. Development takes about 280 days.

Chicken - embryo develops and hatches in 20-21 days. Historically these are one of the first embryos studied. Cutting a window in the egg shell allows direct observation of the embryo. Hamburger & Hamilton chicken development staging is a key embryological tool.

Echidna - not a typical embryo used in developmental studies, much work is still required to determine this unique monotreme embryonic stages of development.

Fly- The fruitfly (drosophila) was and is the traditional geneticist's tool. It has been transformed to an magnificent embryologist's tool, with developmental mechanisms being uncovered in this system combined with homolgy gene searches in other species. Genome has been sequenced!

Frog- The frog was used by many of the early embryology investigators and currently there are many different molecular mechanisms concerning development of the frog.

Guinea Pig- The guinea pig has been used as a model animal in many animal model studies; developmental, dietary, tetragenic, including the effects of maternal temperature on development.

Mouse- The mouse has always been a good embryological model, easy to generate (litters 8-20) and quick (21d). Mouse embryology really expanded when molecular biologists used mice for gene knockouts.

Platypus - not a typical embryo used in developmental studies, with an amazing sex chromosome organization, though we still no very little about the embryonic stages of this unique monotreme development.

Rabbit- along with human, are the few species which show birth defects with thalidomide (teratogenic effects) which were not detected with prior testing on other species.

Rat- available as inbred, outbred and mutant strains. They have been generally beaten as a model by their mice brethren, as the molecular tools that became available (stem cells, knockout genes, etc). Rat embryos do have the advantage of being much larger than mouse embryos and easy to breed. Rat development is also generally 1 day behind from mouse.

Worm- early embryological studies of the worm Caenorhabditis elegans (C.Elegans, so called because of its "elegant" curving movement) characterized the fate of each and every cell in the worm through all stages of development. This worm has recently had its entire genome sequenced.

Zebrafish- are seen as the latest "model' for embryological development studies. They develop as practically "see through" embryos, all internal development can be clearly observed from the outside in the living embryo.

Medaka Oryzias latipes or Japanese rice fish is a member of the killifish family.