Biology subjects

Perrot, C.

Publications and source records attributed to Perrot, C..

4 recordsLinked to original sources

bioRxiv2024

Neuronal activity promotes axonal node-like clustering prior to myelination and remyelination in the central nervous system.

Nodes of Ranvier ensure the fast saltatory conduction along myelinated axons, through their enrichment in voltage-gated sodium and potassium channels. We and others have shown that node-like cluster assembly can occur before myelination. In multiple sclerosis, demyelination is associated with node of Ranvier disassembly, but node-like reassembly can occur prior to remyelination. Given the crucial role of neuronal activity in inducing (re)myelination, we asked whether neuronal activity could regulate node-like clustering. We show that node-like clustering is promoted by neuronal activity and decreased when excitatory glutamatergic receptors are inhibited. Altering glutamatergic neurotransmission leads to the downregulation of Nav1.1 expression, which we show to be critical for node-like clustering. Neuronal activity also promotes node-like clustering in remyelination. As node-like clusters modulate conduction velocity and myelination initiation along axons, we propose that activity-dependent node-like clustering could modulate neuronal network establishment, as well as myelination regulation and patterning during development, plasticity and repair.

neuroscience↗

bioRxiv2023

Effects of atmospheric CO2 concentration on transpiration and leaf elongation responses to drought in wheat, perennial ryegrass and tall fescue

We studied the effects of atmospheric CO2 concentration ([CO2]) on the leaf growth response to drought in perennial ryegrass, tall fescue and wheat. Plants were grown in growth chambers at either 200 or 800 ppm of CO2. At leaf 6-7 unfolding, half of the plants were subjected to severe drought. Leaf elongation rate (LER) was measured daily, while plant transpiration was continuously recorded gravimetrically. Water-soluble carbohydrate concentration, water and osmotic potentials in the leaf growing zone were measured at drought onset, at mid-drought and at the time of leaf growth cessation. [CO2] caused stomata closure and therefore reduction of instantaneous transpiration rate and water loss. As a result, CO2 mitigated the impacts of drought on LER and delayed growth cessation for all three species. For ryegrass, LER and soil relative water content (SRWC) relation was improved with CO2, presumably due to a better stomatal regulation. CO2 did not affect nighttime water potential nor osmotic potential of the growing zone. Related to leaf growth, we observed the main effect of CO2 on tillering but no effect on the plant development. In total, water consumption was similar (wheat, tall fescue) or greater (ryegrass) with CO2.

plant biology↗

bioRxiv2023

Use of linear features by red-legged partridges in an intensive agricultural landscape: implications for landscape management in farmland

Current agricultural practices and change are the major cause of biodiversity loss. An important change associated with the intensification of agriculture in the last 50 years is the spatial homogenization of the landscape with substantial loss of such biodiversity-rich elements as seminatural linear features (hedgerows, field margins, grassy strips, etc.). In Europe, some management prescriptions serve to increase heterogeneity by the creation of these seminatural linear features which are not being used primarily for agricultural production. However, these elements are not equal in their support for biodiversity according to their structure and composition. The aim of this study is to determine the importance of landscape heterogeneity and specifically linear features on the spatial distribution of red-legged partridges, a small game species in decline in Europe. Through GPS-monitoring of adult birds, we first assess home range size throughout the year and during the breeding season, in relation to breeding status and to linear features (seminatural linear vegetation and tracks-roads for human traffic) density. Then, we focus on habitat selection during the breeding period in relation to linear features. We found that linear elements shape the use of space by red-legged partridges according to their reproductive status. Traffic routes and seminatural features structured by both herbaceous and woody cover, negatively influenced home range size. Further, breeding birds select linear elements with herbaceous cover while non-breeders select linear elements with woody cover, underlining the different needs of birds according to their breeding status. All birds selected areas near tracks, but non-breeders seemed to avoid roads. This study shows the importance for this species of the linear components that structure the agricultural landscape. We propose recommendations to promote the presence of the red-legged partridge in this agricultural environment but also of the biodiversity in general.

ecology↗

bioRxiv2023

First report of a successful development of yam hybrids (Dioscorea alata L.) from lyophilized and long-term stored pollens

BackgroundGreater yam, Dioscorea alata L., is a significant food security crop in tropical areas. However, low genetic diversity and various biological constraints, including susceptibility to viruses, ploidy, erratic and low flowering intensity, and asynchronous flowering hinder successful hybrid development and genetic gains in greater yam breeding programs. Therefore, pollen storage has gained much attention to facilitate genetic material exchanges, artificial pollinations and to increase the genetic gains in breeding programs. This 4-year study aimed at developing a practical long-term pollen storage technique for the successful development of yam hybrids. Fresh pollens were collected from two D. alata males, then lyophilized (two lyophilization treatments were applied), followed by storage at room temperature (24-25 {degrees}C) for 12 months. Moreover, the lyophilized and stored pollens were tested for viability by crossing with four female varieties. ResultsOur results showed that lyophilization is effective for achieving viable pollens after 12 months of storage. Treatment 1 (48 h drying) showed higher pollen germination and fertility rates than Treatment 2 (72 h drying). Although we observed a reduction in viability of lyophilized pollens after 12 months of storage, we generated hybrid seedlings with success rates from 12 to 21% compared to 21-31% when using fresh pollens. Paternity testing based on molecular genotyping confirmed the hybrid status of the obtained seedlings, which grew well in a greenhouse. ConclusionsThe results signify the importance of pollen lyophilization for yam breeding programs.

plant biology↗