The role of seed size in dispersal by a scatter-hoarding rodent

A field experiment was conducted in the Nouragues Reserve, an undisturbed lowland rain forest in French Guiana, to test possible selective pressures towards higher seed value of Carapa procera by scatter-hoarders, and to quantify survival probabilities of seeds harvested and cached by red acouchies (Myoprocta exilis). The following hypotheses were also tested: (1) large seeds are more likely to be harvested by acouchies than small seeds; (2) large seeds are harvested by acouchies more quickly than small seeds; (3) large seeds harvested by acouchies have a higher probability than small seeds to be cached rather than eaten; (4) large seeds are cached further away and in lower densities than small seeds; (5) large seeds are recovered from caches and consumed at lower rates than small seeds; and (6) large seeds have higher survival probabilities than small seeds. All seeds were removed within 1.5 days, except for three seeds, which were removed 1-2 days later, thus hypothesis 1 was not confirmed. A total of 362 seeds were located after dispersal wherein 84% was cached and relatively few seeds (16%) were eaten, which confirms hypothesis 3. The distance at which acouchy caches were found immediately after dispersal was highly variable, both within and among plots. The nearest cache was found <1 m from the plot, from which the farthest was 124 m away. Cache distance increased with seed size, as predicted by hypothesis 4. There was also great variation in spatial isolation of acouchy caches, both within and among plots. Recovery of seeds did not necessarily lead to seed consumption since many seeds were reached or were not found again. Larger seeds had a higher probability of being recached rather than eaten while consumed seeds were found much closer to the cache site than recached seeds. These results support hypothesis 5. Seed mass strongly affected the fate pathways of seeds and how long seeds were kept in stock. The ultimate probability of survival increased with seed mass, as posited by hypothesis 6

Transcriptomic analysis of diabetic kidney disease and neuropathy in mouse models of type 1 and type 2 diabetes

Diabetic kidney disease (DKD) and diabetic peripheral neuropathy (DPN) are common complications of type 1 (T1D) and type 2 (T2D) diabetes. However, the mechanisms underlying pathogenesis of these complications are unclear. In this study, we optimized a streptozotocin-induced db/+ murine model of T1D and compared it to our established db/db T2D mouse model of the same C57BLKS/J background. Glomeruli and sciatic nerve transcriptomic data from T1D and T2D mice were analyzed by self-organizing map and differential gene expression analysis. Consistent with prior literature, pathways related to immune function and inflammation were dysregulated in both complications in T1D and T2D mice. Gene-level analysis identified a high degree of concordance in shared differentially expressed genes (DEGs) in both complications and across diabetes type when using mice from the same cohort and genetic background. As we have previously shown a low concordance of shared DEGs in DPN when using mice from different cohorts and genetic backgrounds, this suggests that genetic background may influence diabetic complications. Collectively, these findings support the role of inflammation and indicate that genetic background is important in complications of both T1D and T2D. © 2023 Company of Biologists Ltd. All rights reserved.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]