Question

Regarding studies in early development of vertebrates (frog and mouse):

A) What do you think is the most striking similarity between the way these organisms specify their anterior structures?

B) What do you think is the most striking difference in the way these organisms specify their anterior structures?

C) What are the similarities and differences between these mechanisms and the way that Drosophila specifies its anterior/posterior structures?

Answer 1

• A) Comparison of mouse and frog anterior structure : several unique aspects in frogs provide advantages for serving as a model to elucidate molecular mechanisms of TH signaling during development in vertebrates including humans . The key natural history asserts for frogs are their exaggerated TH - dependent development , large clutch size , and free living embryos / tadpoles giving rise to-
• Ease of observation, tissue accessibility , and hormone manipulation.
• Lack of influence of maternal endocrine system on fetal development .
• Natural development with unligande TR s. The shorter generation time historical advantage of mice for genome manipulation , and evolutionary closeness to humans are powerful aspects of the mouse model for TH signaling studies .However , with advances in gene .Disruption technology and sequencing of X .tropicalis and Z. laevis genomes , the disparity in genomics tools between frogs and mice is closing .
  • B) comparison of vertebrae between Rat and Frog : Rat's vertebrae is slightly long , and very flexible , allowing it to enter small holes when needed, In addition , its tai helps keep its balance , and gives them more control.

Frog's vertebrae: A frogs vertebrae is very short , and less complex , It has an absence of a neck and tail , that gives it a lack of speed , but powerful jump heights , and allow .It to control itself .

Comparison of classification :While both rats and frogs have the same kingdom and phylum, the orders of classification start to change , as the rat represents Mammalia while the frog represents Amphibia .Mammals are warm blooded , and give birth from their body , while also having fur/ hair on them .Amphibians are cold blooded , and give birth by laying eggs , but don't have any fur / hair on them.

​​​​​​c) Drosophila

Drosophilia melanogaster is an important model organism that can be used as a powerful genetic tool to analyze the physiological functions of various molecules .

Most Drosophilia are small , about 2-4 mm long , but some are larger than a house fly .They are typically pale yellow to reddish brown or black and transverse black rings across the abdomen with brick red eyes .Many species have distinct black patterns on the wings with plumose and arista antennae, bristling on the head and thorax .

Drosophilia belongs to the family Drosophilidae , where members are most frequently called the fruit flies .since ancient time , Drosophilia is used as a model and toolbar for biology , genetics , medicine , human disease, and stem cell research .