Researchers from the Institute of Integrative Systems Biology (I2SysBio), a joint center of the University of Valencia (UV) and the Higher Council for Scientific Research (CSIC), among other centers, have discovered that the gene for the Pigment-Dispersing Factor (PDF) protein, which is part of the circadian clock of insects (responsible for daily rhythms), is also found in the pea aphid. The research has been published in the prestigious journal Open Biology, in which, in addition, an image of this work is the cover of the month of July.

“This research is important to understand how the biological cycles are regulated, not only of aphids, but of numerous insects, and to outline the design of strategies or tools for their control. Ideally, if we could avoid the annual entry into diapause (physiological state of inactivity) of an insect vector or pest, it would be unable to resist the harsh conditions of winter. And vice versa, if we induce diapause in a benign period, the insect will be absent, which will avoid its potential damage," say David Martínez Torres, professor of Genetics (UV) and researcher at I²SysBio and Gustavo L. Rezende, distinguished researcher at the center. mixed.

Research has discovered that the PDF gene is present in all aphid species, when, 10 years after the publication of the first pea aphid genome, it was already assumed that these insects lacked this gene. Furthermore, “we have also located the neurons that produce this neuropeptide (small proteins that act as chemical messengers) and their connections, on the one hand, with photoreceptors and, on the other, with cells involved in the response through the insulin pathway,” according to the two researchers from the “Aphid Biological Cycles” Research Group of the I²SysBio.

The work also confirms that on short days more neuropeptide is produced than on long days, which could be a signal (or part of it) that informs about the photoperiod (or length of the day), according to the researchers. animal have adaptations known as biological rhythms to the rhythms of the Earth. Circadian rhythms are adaptations to daily changes, while seasonal rhythms are important to changes throughout the year. Among the latter we can highlight the migrations of birds or the hibernation of bears and diapause in insects. But you have to anticipate the arrival of bad weather, and you cannot make a mistake and migrate early or do it too late, and for this the most reliable clue is the length of the day.

Photoperiodism is the ability of numerous species to detect changes in the length of the day (photoperiod) and respond with changes in their physiology or behavior. In insects it is only partially known how the photoperiodic system works and in some species the involvement of PDF (which is part of the circadian clock of all insects) has been demonstrated. Aphids are photoperiodic insects par excellence, with a life cycle absolutely determined by the photoperiod. style="text-align:justify"> the transmission of the photoperiodic message that modulates the seasonal response in these insects.” After the description of photojournalism for the first time in plants in 1920, the year 2023 marks the centenary of the description of aphids as the first photoperiodic animals. style="color:black">

This research, in which Francesca Sara Colizzi and Charlotte Helfrich-Förster from the Universität Würzburg in Germany and Jan A. Veenstra from the Université de Bordeaux in France, has been supported by the Ministry of Science and Innovation, the Ministry of Universities (Ayudas María Zambrano) and by funds from the European Union (Horizon 2020 Program).

Article:

Colizzi FS, Veenstra JA, Rezende GL, Helfrich-Förster C and Martínez-Torres D. 2023 Pigment-dispersing factor is present in circadian clock neurons of pea aphids and may mediate photoperiodic signaling to insulin-producing cells. Open Biol. 13: 230090. https://doi.org/10.1098/rsob.230090

Attached captions:

1. I²SysBio researchers participating in the study. Gustavo Lazzaro Rezende (left) and David Martínez Torres (right). style="text-align:justify">2. Cover of the July Open Biology magazine, with an image of the pea aphid Acyrthosiphon pisum. Author: Gustavo Lazzaro Rezende.

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