Biology subjects

Zhu-Salzman, K.

Publications and source records attributed to Zhu-Salzman, K..

2 recordsLinked to original sources

bioRxiv2024

The maternal vGluT2 and embryonic mGluR3 signaling relay system controls offspring wing dimorphism in pea aphid

Transgenerational phenotypic plasticity (TPP) refers to the phenomenon that environmental conditions experienced by one generation can influence the phenotype of subsequent generations to adapt to the environment without modification of their DNA sequences. Aphid wing dimorphism is a textbook example of TPP by which a maternal aphid perceives the environmental cues to decide the wing morph of her offspring. However, the signaling mechanism from mother to daughter remains unclear. In this study, we showed that the population density and physical contact caused high proportion of winged offspring in the pea aphid Acyrthosiphon pisum. Its vesicular glutamate transporter 2 (ApvGluT2) and metabotropic glutamate receptor 3 (ApmGluR3) were identified by tissue-specific RNA-seq as differentially expressed genes in the head and embryo respectively between solitary and more densely housed maternal aphids. Elevated expression of brain ApvGluT2 and embryonic ApmGluR3 led to increases in the winged proportion. Knockdown of either gene inhibited phosphorylation of ApFoxO in embryos. Furthermore, EMSA showed that dephosphorylated ApFoxO directly bound to the promotor of hedgehog (ApHh), a morphogen gene for wing development, to repress its transcription in stage 20 embryos, causing a lower winged proportion. Our results demonstrated that brain vGluT2 and embryonic mGluR3 coordinately relayed the maternal physical contact signals and control wing development in offspring, showcasing a novel regulatory mechanism underlying physical contact-dependent, transgenerational wing dimorphism in aphids.

zoology↗

bioRxiv2022

A Novel Gene REPTOR2 Activates the Autophagic Degradation of Wing Disc in pea aphid

Wing dimorphism is an evolutionarily adaptive trait to maximize insect fitness under various environments, by which the population could be balanced between migration and reproduction. Most studies concern the regulatory mechanisms underlying the stimulation of wing morph in aphids, but relatively little research addresses the molecular basis of wing loss. Here, we found that the wing disc of wingless-destined pea aphids degenerated 30 h post birth by autophagic rather than apoptotic degeneration, whereas winged-destined aphids developed normally. Activation of autophagy in 1st instar nymphs reduced the proportion of winged aphids, and suppression of autophagy increased the proportion. The REPTOR2 gene associated with TOR signaling pathway was identified by RNA-seq as a differentially expressed gene between the two morphs, with higher expression in the thorax of wingless-destined aphids. Further genetic analysis indicated that REPTOR2 could be a novel gene derived from a gene duplication event exclusively in pea aphid on autosome A1 but translocated to the sex chromosome. Knockdown of REPTOR2 reduced autophagy in the wing disc and increased the proportion of winged aphids. In agreement with REPTORs canonical negative regulatory role of TOR on autophagy, winged-destined aphids had higher TOR expression in the wing disc. Suppression of TOR activated autophagy of the wing disc and decreased the proportion of winged aphids, and vice versa. These results revealed that the TOR signaling pathway controlled degradation of the wing disc in pea aphids, and that REPTOR2 could modulate this autophagic degradation.

developmental biology↗