As we have seen in earlier post that in Tribolium , the second thoracic segment (T2 segment) bears sclerotized elytra and T3 bears more classical membranous wings for flight.The difference between dipterans and coleopetrans in developing membranous wings for flight( Dipterans have flight wings on T2 and Coleopetrans on T3) could be due to different expression pattern of Ubx hox protein in these two insects orders. However, detection of Ultrathorax (Utx), the protein product of the Tribolium Ubx orthologue, showed that Utx, like its Drosophila counterpart, is expressed in …

Do you know that Beetles account for around 25% of all known life-forms on this planet. They belong to the order Coleoptera, which happens to be the largest and most diverse order, not only in the insect class, but in the entire animal kingdom. It is believed that there are eight times as many beetle species as there are fish, amphibian, reptile, bird and mammal species all put together. Eight times!!! Those are really huge numbers of beetles which goes on to tell us that these creatures can survive in …

Bithorax complex in Drosophila consists of three homeodomain encoding proteins : Ultrabithorax (Ubx), abdominal-A (abd-A) and Abdominal-B (Abd-B). The function of these bithorax genes is to pattern entire abdomen ( A1-A9 segments ) and a part of third thoracic segment ,which happens to be their normal expression domain in embryos. These Hox proteins are expressed within specific parasegments (PS) , anatomical units that include the posterior portion of one segment and the anterior portion of the adjacent segment.
But the problem is that we have only three proteins and they need …

How transcription factors achieve their in vivo specificities is a fundamental question in biology. Regulation of Distalless (dll) gene in insects served as an excellent model to study mechanisms of Hox genes and this is the topic of our classic paper today. Richard mann’s lab published some stunning stuff on role played by segmentation genes in regulation of distalless gene in 2004 Nature issue. This article is a real classic providing some finer details in repression of distalless in abdomen of insects. Ever since the first paper by Vachon et …

What makes Sean carroll’s articles and Books so unique and impressive? One answer to that would be some brilliant writing involved in them,which makes readers understand the content easily.Today we will look back into his article from Current Biology ,published on 20 January 1999 describing role of Ultrabithorax (Ubx) in Butterfly wings.
Hox genes control many features like segment morphology, appendage number(Arthropods) and pattern,axial morphology and limb pattern (vertebrates) ,which played significant role in modifications to their respective body plans during evolution.The morphological and functional evolution of appendages has played a …

Evolution is not always about inventing new proteins but using the same old proteins in a different ways to attain a new function and there by modifying the body plan ,leading to development of new species.Drosophila fushi tarazu serves as a great example for evolution in action and this was demonstrated by Ulrike Lohr et al in 2001 through their current biology article.This happens to be my one of all time favorite work on Hox genes as it displays gradual change in gene function during the course of …

To begin the new section “Classics”,where i discuss some outstanding papers in the field .we will look into an article from Weatherbee et al published in genes and dev in 1998.This article comes the lab of Sean carroll ,considered to be temple of evo devo, forms one reason for selecting this article as a starter for this section .The other reason being this kind of work is pretty close to my heart because my first experience with fruit flies and research world came from a project on similar lines.I …