This section contains reviews/summaries/critiques of selected published research articles in broad areas of biology, including evolutionary biology, developmental biology, and genetics. Some of these evaluations are part of my F1000 reviews (see my F1000 profile here).
Origin and diversification of wings: Insights from a neopteran insect
Medved et al., Proc Natl Acad Sci U S A 2015 Dec 29; 112(52):15946-51
PMID: 26668365 DOI: 10.1073/pnas.1509517112
This study reports new insights into the evolution of insect wings. The middle segment of insect body, termed thorax, is composed of three segments (T1, T2, and T3). Although the fossil records provide evidence for wing-like structures on all three segments, extant species lack T1 appendages. While there is significant information available on the morphology of T2 and T3 wings, we know little about how such forms originated and diversified.
The SIAH E3 ubiquitin ligases promote Wnt/β-catenin signaling through mediating Wnt-induced Axin degradation.
Lei Ji et al., Genes & Development 2017, vol.31, 904–915
In this paper, authors demonstrate that an E3 ligase (IAH1/2 or SIAH) initiates a positive feedback loop to maintain activation of Wnt signaling. SIAH interacts with a VxP motif in Axin that is located within the GSK3-binding domain of the protein. Upon initial activation of Wnt signaling, Axin dissociates from the destruction complex, making it accessible to SIAH-mediated ubiquitination and degradation. This sets a feed-forward mechanism leading to sustained activation of the pathway.