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41.
Early spermatogenesis in Rhynchosciara 总被引:1,自引:0,他引:1
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Kalina T. J. Davies Laurel R. Yohe Jesus Almonte Miluska K. R. Snchez Edgardo M. Rengifo Elizabeth R. Dumont Karen E. Sears Liliana M. Dvalos Stephen J. Rossiter 《Molecular ecology》2020,29(10):1839-1859
Changes in behaviour may initiate shifts to new adaptive zones, with physical adaptations for novel environments evolving later. While new mutations are commonly considered engines of adaptive change, sensory evolution enabling access to new resources might also arise from standing genetic diversity, and even gene loss. We examine the relative contribution of molecular adaptations, measured by positive and relaxed selection, acting on eye‐expressed genes associated with shifts to new adaptive zones in ecologically diverse bats from the superfamily Noctilionoidea. Collectively, noctilionoids display remarkable ecological breadth, from highly divergent echolocation to flight strategies linked to specialized insectivory, the parallel evolution of diverse plant‐based diets (e.g., nectar, pollen and fruit) from ancestral insectivory, and—unusually for echolocating bats—often have large, well‐developed eyes. We report contrasting levels of positive selection in genes associated with the development, maintenance and scope of visual function, tracing back to the origins of noctilionoids and Phyllostomidae (the bat family with most dietary diversity), instead of during shifts to novel diets. Generalized plant visiting was not associated with exceptional molecular adaptation, and exploration of these novel niches took place in an ancestral phyllostomid genetic background. In contrast, evidence for positive selection in vision genes was found at subsequent shifts to either nectarivory or frugivory. Thus, neotropical noctilionoids that use visual cues for identifying food and roosts, as well as for orientation, were effectively preadapted, with subsequent molecular adaptations in nectar‐feeding lineages and the subfamily Stenodermatinae of fig‐eating bats fine‐tuning pre‐existing visual adaptations for specialized purposes. 相似文献
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Availability of shelter is an important component of habitat selection for animals as it can influence survival (protection against harsh physical conditions and predation) and growth (energy acquisition and expenditure). Few studies address the effect of shelter on metabolic expenditures associated with non-mechanical tasks (excluding station holding or movement). The main goal of this study was to investigate the influence of shelter use on metabolic traits of smallmouth bass (Micropterus dolomieu) from two populations (Kiamika River and Lake Long). Respirometry experiments on smallmouth bass were conducted to measure standard metabolic rate (SMR), resting metabolic rate (RMR), aerobic scope (AS), recovery time (RT) and excess post-exercise oxygen consumption (EPOC) in the presence or absence of shelter. The presence of shelter did not affect most metabolic traits, except for RMR, which was reduced in the presence of shelter for Lake Long fish. The results of this study also show that larger fish had lower SMR in the presence of shelter than when it was absent. When accounting for social hierarchy, there were no differences in most metabolic traits in dominant or subordinate fish in the presence or absence of shelter, except for RT, which was significantly lower in the presence of shelter for dominant fish. These results do not support the existence of an unequivocal relationship between individual metabolic traits and the presence of shelter. If physiological motives may influence the use of shelter, sheltering in itself might not have important consequences on energy expenditures required for non-mechanical tasks. 相似文献
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Emmanuelle Braud Muriel Duflos Guillaume Le Baut Pierre Renard Bruno Pfeiffer Gordon Tucker 《Journal of enzyme inhibition and medicinal chemistry》2013,28(3):253-257
The synthesis and pharmacological evaluation of new 3-(imidazol-4(5)-ylmethylene)-2,3-dihydrobenzo[b]furan-2-ones 8-10 and 3-(3,5-dimethylpyrrol-2-ylmethylene)-2,3-dihydrobenzo[b]furan-2-one 11, analogues of SU-5416, as potential inhibitors of angiogenesis, are reported. Compounds 8 and 11 were prepared by a Knoevenagel reaction starting from 2-hydroxyphenylacetic acid 2 and 4-formylimidazole 5 or 2-formyl-3,5-dimethylpyrrole 7, followed by acid-catalysed cyclodehydration. For compounds 9 and 10, an alternative method was used; it consisted in carrying out the Knoevenagel reaction with the 2,3-dihydrobenzo[b]furan-2-ones 3 and 4. The antiangiogenic activity of these compounds was evaluated in the three-dimensional in vitro rat aortic rings test at 1 μM. At this concentration, compound 11 induced a decrease of angiogenesis comparable to that observed with SU-5416; the vascular density index at 1 μM of 11 and SU-5416 were 30±10 and 22±4% of control, respectively. 相似文献
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Diego Sustaita Emmanuelle Pouydebat Adriana Manzano Virginia Abdala Fritz Hertel Anthony Herrel 《Biological reviews of the Cambridge Philosophical Society》2013,88(2):380-405
Human beings have been credited with unparalleled capabilities for digital prehension grasping. However, grasping behaviour is widespread among tetrapods. The propensity to grasp, and the anatomical characteristics that underlie it, appear in all of the major groups of tetrapods with the possible exception of terrestrial turtles. Although some features are synapomorphic to the tetrapod clade, such as well‐defined digits and digital musculature, other features, such as opposable digits and tendon configurations, appear to have evolved independently in many lineages. Here we examine the incidence, functional morphology, and evolution of grasping across four major tetrapod clades. Our review suggests that the ability to grasp with the manus and pes is considerably more widespread, and ecologically and evolutionarily important, than previously thought. The morphological bases and ecological factors that govern grasping abilities may differ among tetrapods, yet the selective forces shaping them are likely similar. We suggest that further investigation into grasping form and function within and among these clades may expose a greater role for grasping ability in the evolutionary success of many tetrapod lineages. 相似文献
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Emmanuelle Stoetzel Christiane Denys Jacques Michaux Sabrina Renaud 《Biological journal of the Linnean Society. Linnean Society of London》2013,109(3):599-621
North Africa is an intricate biogeographical region at the crossroads of immigration waves from tropical Africa and Asia. Species confined between various barriers (Atlas Mountains, arid environments such as the Sahara in the south, water masses such as the Mediterranean Sea in the north, and the Atlantic Ocean in the west) were generally forced to adapt locally to environmental changes instead of tracking their habitat by shifting their distribution area. The present study aims at providing first insight into the evolution of the genus Mus, and more specifically of the western Mediterranean species Mus spretus in this area. The study relies on the abundant Late Pleistocene and Middle Holocene fossil assemblage from the El Harhoura 2 cave (Rabat‐Témara, Morocco). This exceptional record was studied using geometric morphometrics applied to first upper and lower molars, constituting the most informative and best preserved fossil remains for such small rodents. Two main issues were addressed. (1) Geometric morphometrics was used to clarify taxonomic status and phylogenetic relationships among fossil and modern species in this area. Morphometric analysis revealed good discrimination of most modern and fossil species but failed to document intermediate forms tracing anagenetic evolution. Not mutually exclusive, the occurrence of complex processes of morphological evolution in this genus such as parallel evolution and the action of stabilizing selection may make it difficult to translate patterns of morphological evolution into phylogenetic conclusions. (2) The record was shown to document a sequence of intraspecific evolution of M. spretus. The morphology of the molars through the fossil record of El Harhoura 2 was surprisingly stable despite extensive modern variation. The limited temporal variation largely failed to correlate to palaeoenvironmental proxies. The mouse fossil record at El Harhoura 2 thus presents an intriguing case of morphological stasis despite extensive environmental changes. This long‐term stability may have been recently perturbed by anthropogenic factors including landscape changes and introduction of various competitors and predators, leading to a size reduction. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109 , 599–621. 相似文献