21 research outputs found

    Convergent sequence evolution between echolocating bats and dolphins

    Get PDF
    SummaryCases of convergent evolution — where different lineages have evolved similar traits independently — are common and have proven central to our understanding of selection. Yet convincing examples of adaptive convergence at the sequence level are exceptionally rare [1]. The motor protein Prestin is expressed in mammalian outer hair cells (OHCs) and is thought to confer high frequency sensitivity and selectivity in the mammalian auditory system [2]. We previously reported that the Prestin gene has undergone sequence convergence among unrelated lineages of echolocating bat [3]. Here we report that this gene has also undergone convergent amino acid substitutions in echolocating dolphins, which group with echolocating bats in a phylogenetic tree of Prestin. Furthermore, we find evidence that these changes were driven by natural selection

    Cetaceans on a molecular fast track to ultrasonic hearing

    Get PDF
    The early radiation of cetaceans coincides with the origin of their defining ecological and sensory differences [1, 2]. Toothed whales (Odontoceti) evolved echolocation for hunting 36–34 million years ago, whereas baleen whales (Mysticeti) evolved filter feeding and do not echolocate [2]. Echolocation in toothed whales demands exceptional high-frequency hearing [3], and both echolocation and ultrasonic hearing have also evolved independently in bats [4, 5]. The motor protein Prestin that drives the electromotility of the outer hair cells (OHCs) is likely to be especially important in ultrasonic hearing, because it is the vibratory response of OHC to incoming sound waves that confers the enhanced sensitivity and selectivity of the mammalian auditory system [6, 7]. Prestin underwent adaptive change early in mammal evolution [8] and also shows sequence convergence between bats and dolphins [9, 10], as well as within bats [11]. Focusing on whales, we show for the first time that the extent of protein evolution in Prestin can be linked directly to the evolution of high-frequency hearing. Moreover, we find that independent cases of sequence convergence in mammals have involved numerous identical amino acid site replacements. Our findings shed new light on the importance of Prestin in the evolution of mammalian hearing

    Online survey on healthcare skin reactions for wearing medical-grade protective equipment against COVID-19 in Hubei Province, China.

    No full text
    With the spread of Coronavirus Disease 2019 globally, more than 40,000 healthcare staff rushed to Wuhan, Hubei Province to fight against this threatening disease. All staff had to wear personal protective equipment (PPE) for several hours when caring for patients, which resulted in adverse skin reactions and injuries. In this study, we used an online questionnaire to collect the self-reported skin damages among the first-line medical staff in the epidemic. The questionnaire was designed by four front-line wound care nurses and then revised through Delphi consultants. Items mainly focused on the adverse skin reactions and preventive strategies. The survey was distributed through phone application from March 15th to March 20th and received 275 responses in total. The prevalence of skin reactions (212, 77.09%) was high in both head and hands. The common clinical symptoms of skin reactions were redness, device-like mark, and burning pain in face; and dryness, dermatitis, and itch/irritation in hands. Three risk factors included gender, level of protection, and daily wearing time of PPE were identified that caused skin reactions among medical staff. 150 of 275 (54.55%) participants took preventive strategies like prophylactic dressings, however, more than 75% users had little knowledge about dressings. We suggest the frontline staff strengthened the protection of skin integrity and reduced the prevalence of adverse skin reactions after professional education

    Biomass Production of Three Biofuel Energy Plants’ Use of a New Carbon Resource by Carbonic Anhydrase in Simulated Karst Soils: Mechanism and Capacity

    No full text
    To determine whether the bicarbonate in karst limestone soil could be used as a new carbon resource for biomass production by the catalysis of carbonic anhydrase (CA), a simulative karst drought stress experiment was designed and performed. Three plants used for biofuel energy, Orychophragmus violaceus L. (Ov), Brassica juncea L. (Bj), and Euphorbia lathyris L. (El), were grown under simulated karst drought stress. In response to drought stress, the photosynthesis of the three energy plants was inhibited, but their CA activity increased. The hypothesis was confirmed by plant physiological and stable isotope techniques. The obtained results showed that plant biomass was produced with atmospheric CO2 as well as bicarbonate under drought stress. Bicarbonate use was proportional to the CA activity of the plants. With high CA activity over a long period, El had the highest proportional bicarbonate use compared to Ov and Bj, reaching 26.95%. Additionally, a new method is proposed for the screening of plants grown for energy in karst habitats
    corecore