Biology subjects

Cardini, A.

Publications and source records attributed to Cardini, A..

4 recordsLinked to original sources

bioRxiv2020

Transcriptional regulation of genes involved in Zn transport after foliar Zn application to Medicago sativa

Zinc (Zn) is an essential micronutrient for both plants and animals, and Zn deficiency is one of the most widespread problems for agricultural production. Although many studies have been performed on the biofortification of staple crops with Zn, few studies have focused on forage crops. In this study the molecular mechanisms of Zn transport-related in Medicago sativa L. were investigated following foliar Zn applications aimed at increasing the accumulation of Zn in edible tissues. Zinc uptake and redistribution between shoot and root were determined following the application of six Zn doses to leaves (0, 0.01, 0.1, 0.5, 1, 10 mg Zn plant-1). Twelve putative genes encoding proteins involved in Zn transport (MsZIP1-7, MsZIF1, MsMTP1, MsYSL1, MsHMA4 and MsNAS1) were identified and the changes in their expression following foliar Zn application were quantified using newly designed RT-qPCR assays. Shoot and root Zn concentration was increased following foliar Zn applications [≥] 0.1 mg plant-1. Increased expression of MsZIP2, MsHMA4 and MsNAS1 in shoots, and of MsZIP2 and MsHMA4 in roots, was observed with the largest Zn dose. By contrast, MsZIP3 was downregulated in shoots at Zn doses [≥] 0.1 mg plant-1. Three functional modules were identified in the M. sativa response to foliar Zn application: genes involved in Zn uptake by cells, genes involved in vacuolar Zn sequestration and genes involved in Zn redistribution within the plant. These results will inform genetic engineering strategies aimed at increasing the efficiency of crop Zn biofortification. One-sentence summaryUpregulation of ZIP2, NASI and HMA4 and downregulation of ZIP3 are associated with Zn sequestration and shoot-to-root translocation in Medicago sativa following foliar Zn biofortification

plant biology↗

bioRxiv2019

How flat can a horse be? Exploring 2D approximations of 3D crania in equids

Quantitative analyses of morphological variation using geometric morphometrics are often performed on 2D photos of 3D structures. It is generally assumed that the error due to the flattening of the third dimension is negligible. However, despite hundreds of 2D studies, few have actually tested this assumption and none has done it on large animals, such as those typically classified as megafauna. We explore this issue in living equids, focusing on ventral cranial variation at both micro- and macro-evolutionary levels. By comparing 2D and 3D data, we found that size is well approximated, whereas shape is more strongly impacted by 2D inaccuracies, as it is especially evident in intra-specific analyses. The 2D approximation improves when shape differences are larger, as in macroevolution, but even at this level precise inter-individual similarity relationships are altered. Despite this, main patterns of sex, species and allometric variation in 2D were the same as in 3D, thus suggesting that 2D may be a source of noise that does not mask the main signal in the data. However, the problem is complex and any generalization premature. Morphometricians should therefore test the appropriateness of 2D using preliminary investigations in relation to the specific study questions in their own samples. We discuss whether this might be feasible using a reduced landmark configuration and smaller samples, which would save time and money. In an exploratory analysis, we found that in equids results seem robust to sampling, but become less precise and, with fewer landmarks, may slightly overestimate 2D inaccuracies.

zoology↗

bioRxiv2019

Craniofacial allometry is a rule in evolutionary radiations of placentals

It has been suggested that larger species of mammals tend to become long-faced when they diverge in size during an evolutionary radiation. However, whether this allometric pattern, reminiscent of ontogenetic changes in skull proportions, is indeed a rule has yet to be thoroughly tested. Using ~6000 adult specimens from 14 phylogenetically well separated and ecomorphologically distinctive lineages, 11 orders, and all superorders of the placentals, I tested each group for positive craniofacial allometry (CREA). The evidence supporting CREA is overwhelming, with virtually all analyses showing proportionally longer faces in bigger species. This corroborates previous studies in other groups, consolidates CREA as a pervasive morphological trend in placental evolution and opens important research avenues for connecting micro- and macro-evolution. If found in even more lineages of non-placental mammals, confirmed in birds, and possibly discovered in other tetrapods, CREA could become one of the most general rules of morphological evolution in land vertebrates.

evolutionary biology↗

bioRxiv2018

Integration and modularity in Procrustes shape data: is there a risk of spurious results?

Studies of morphological integration and modularity are a hot topic in evolutionary developmental biology. Geometric morphometrics using Procrustes methods offers powerful tools to quantitatively investigate morphological variation and, within this methodological framework, a number of different methods has been put forward to test if different regions within an anatomical structure behave like modules or, vice versa, are highly integrated and covary strongly. Although some exploratory techniques do not require a priori modules, commonly modules are specified in advance based on prior knowledge. Once this is done, most of the methods can be applied either by subdividing modules and performing separate Procrustes alignments or by splitting shape coordinates of anatomical landmarks into modules after a common superimposition. This second approach is particularly interesting because, contrary to completely separate blocks analyses, it preserves information on relative size and position of the putative modules. However, it also violates one of the fundamental assumptions on which Procrustes methods are based, which is that one should not analyse or interpret subsets of landmarks from a common superimposition, because the choice of that superimposition is purely based on statistical convenience (although with sound theoretical foundations) and not on a biological model of variance and covariance. In this study, I offer a first investigation of the effects of testing integration and modularity within a configuration of commonly superimposed landmarks using some of the most widely employed statistical methods available to this aim. When applied to simulated shapes with random non-modular isotropic variation, standard methods frequently recovered significant but arbitrary patterns of integration and modularity. Re-superimposing landmarks within each module, before testing integration or modularity, generally removes this artifact. The study, although preliminary and exploratory in nature, raises an important issue and indicates an avenue for future research. It also suggests that great caution should be exercised in the application and interpretation of findings from analyses of modularity and integration using Procrustes shape data, and that issues might be even more serious using some of the most common methods for handling the increasing popular semilandmark data used to analyse 2D outlines and 3D surfaces.

evolutionary biology↗