Molecular evolutionary trends and feeding ecology diversification in the Hemiptera, anchored by the milkweed bug genome.

Background: The Hemiptera (aphids, cicadas, and true bugs) are a key insect order, with high diversity for feeding ecology and excellent experimental tractability for molecular genetics. Building upon recent sequencing of hemipteran pests such as phloem-feeding aphids and blood-feeding bed bugs, we present the genome sequence and comparative analyses centered on the milkweed bug Oncopeltus fasciatus, a seed feeder of the family Lygaeidae.

Results: The 926-Mb Oncopeltus genome is well represented by the current assembly and official gene set.

The beetle amnion and serosa functionally interact as apposed epithelia.

Unlike passive rupture of the human chorioamnion at birth, the insect extraembryonic (EE) tissues - the amnion and serosa - actively rupture and withdraw in late embryogenesis. Withdrawal is essential for development and has been a morphogenetic puzzle. Here, we use new fluorescent transgenic lines in the beetle Tribolium castaneum to show that the EE tissues dynamically form a basal-basal epithelial bilayer, contradicting the previous hypothesis of EE intercalation.

Visualizing late insect embryogenesis: extraembryonic and mesodermal enhancer trap expression in the beetle Tribolium castaneum.

The beetle Tribolium castaneum has increasingly become a powerful model for comparative research on insect development. One recent resource is a collection of piggyBac transposon-based enhancer trap lines. Here, we provide a detailed analysis of three selected lines and demonstrate their value for investigations in the second half of embryogenesis, which has thus far lagged behind research on early stages.

Regulation of expression of Vg and establishment of the dorsoventral compartment boundary in the wing imaginal disc by Suppressor of Hairless.

The transcription factor Suppressor of Hairless (Su(H)) belongs to the CSL transcription factor family, which are the main transcriptional effectors of the Notch-signaling pathway. Su(H) is the only family member in the Drosophila genome and should therefore be the main transcriptional effector of the Notch pathway in this species. Despite this fact, in many developmental situations, the phenotype caused by loss of function of Su(H) is too weak for a factor that is supposed to mediate most or all aspects of Notch signaling.

A Notch-independent function of Suppressor of Hairless during the development of the bristle sensory organ precursor cell of Drosophila.

Su(H)/CBF1 is a key component of the evolutionary conserved Notch signalling pathway. It is a transcription factor that acts as a repressor in the absence of the Notch signal. If Notch signalling is activated, it associates with the released intracellular domain of the Notch receptor and acts as an activator of transcription.