Recent approaches lead to a deeper understanding of diverse segmentation mechanisms in insects, with a focus on the pair-rule genes.

The division of the insect embryo into repeated units - segments - is a fundamental feature of the body plan. The genes controlling this process in Drosophila melanogaster were identified in genetic screens and characterized in that species in numerous studies in the 1980s and 1990s. These genes form a well-established hierarchy and have been leveraged to examine gene regulation, transcriptional machinery, chromatin structure, and more.

C-H/F bond activation and borylation with iron.

Reduction of [K{(pyrrpyr)Fe}(μ-N)] (1) with two equiv. of KC in the presence of crown-ether 18-C-6 yields the N adduct [{K(18-C-6)}(pyrrpyr)Fe(N)] (2). Complex 2 heterolytically splits the C-H bond of benzene to form [{K(18-C-6)}(pyrrpyr)Fe(CH)] (3), whereby usage of a diboron Bpin promotes hydride elimination to form the salt [K(18-C-6)HBPin] (4).

A conserved sequence that sparked the field of evo-devo.

The discovery that homeotic genes in Drosophila are conserved and utilized for embryonic development throughout the animal kingdom, including humans, revolutionized the fields of developmental biology and evolutionary developmental biology (evo-devo). In a pair of back-to-back papers published in Cell in 1984, researchers at the Biozentrum in Basel, Switzerland, showed that the homeobox - previously identified as a sequence shared by homeotic genes in Drosophila - was also present in the genome of diverse animals. The first paper (McGinnis et al.

Same rule, different genes: is a pair-rule gene in the milkweed bug .

Morphological features of organismal body plans are often highly conserved within large taxa. For example, segmentation is a shared and defining feature of all insects. Screens in identified genes responsible for the development of body segments, including the "pair-rule" genes (PRGs), which subdivide embryos into double-segment units in a previously unexpected pre-patterning step.