Persistent Parental RNAi in the Beetle Involves Maternal Transmission of Long Double-Stranded RNA (Advanced Genetics 3/03).

dsRNA Uptake In article 2100064 by Kristen A. Panfilio and co-workers, the cuticle exoskeleton of flour beetle larvae reveals normal anatomy (above: head-to-tail in blue-to-red) and long-term parental RNAi knockdown (below), here showing a mirror-image duplication of the abdomen (red termini to yellow center). Strong knockdown can persist for months despite transmission of full-length double-stranded RNA (dsRNA) from the mother into the egg, depleting maternal dsRNA levels.

Persistent Parental RNAi in the Beetle Involves Maternal Transmission of Long Double-Stranded RNA.

Parental RNA interference (pRNAi) is a powerful and widely used method for gene-specific knockdown. Yet in insects its efficacy varies between species, and how the systemic response is transmitted from mother to offspring remains elusive. Using the beetle , an RT-qPCR strategy to distinguish the presence of double-stranded RNA (dsRNA) from endogenous mRNA is reported.

Enhanced genome assembly and a new official gene set for Tribolium castaneum.

Background: The red flour beetle Tribolium castaneum has emerged as an important model organism for the study of gene function in development and physiology, for ecological and evolutionary genomics, for pest control and a plethora of other topics. RNA interference (RNAi), transgenesis and genome editing are well established and the resources for genome-wide RNAi screening have become available in this model. All these techniques depend on a high quality genome assembly and precise gene models.

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.

Novel functions for Dorsocross in epithelial morphogenesis in the beetle Tribolium castaneum.

Epithelial morphogenesis, the progressive restructuring of tissue sheets, is fundamental to embryogenesis. In insects, not only embryonic tissues but also extraembryonic (EE) epithelia play a crucial role in shaping the embryo. In Drosophila, the T-box transcription factor Dorsocross (Doc) is essential for EE tissue maintenance and therefore embryo survival.

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.

Evolution of epithelial morphogenesis: phenotypic integration across multiple levels of biological organization.

Morphogenesis involves the dynamic reorganization of cell and tissue shapes to create the three-dimensional body. Intriguingly, different species have evolved different morphogenetic processes to achieve the same general outcomes during embryonic development. How are meaningful comparisons between species made, and where do the differences lie? In this Perspective, we argue that examining the evolution of embryonic morphogenesis requires the simultaneous consideration of different levels of biological organization: (1) genes, (2) cells, (3) tissues, and (4) the entire egg, or other gestational context.

Measuring telomere length and telomere dynamics in evolutionary biology and ecology.

Telomeres play a fundamental role in the protection of chromosomal DNA and in the regulation of cellular senescence. Recent work in human epidemiology and evolutionary ecology suggests adult telomere length (TL) may reflect past physiological stress and predict subsequent morbidity and mortality, independent of chronological age.Several different methods have been developed to measure TL, each offering its own technical challenges.

Inheritance of telomere length in a bird.

Telomere dynamics are intensively studied in human ageing research and epidemiology, with many correlations reported between telomere length and age-related diseases, cancer and death. While telomere length is influenced by environmental factors there is also good evidence for a strong heritable component. In human, the mode of telomere length inheritance appears to be paternal and telomere length differs between sexes, with females having longer telomeres than males.