Convergent evolution in high-altitude and marine mammals:Molecular adaptations to pulmonary fibrosis and hypoxia

High-altitude and marine mammals inhabit distinct ecosystems but share a common challenge:hypoxia.To survive in low-oxygen environments,these species have evolved similar phenotypic pulmonary adaptations,characterized by a high density of elastic fibers.In this study,we explored the molecular mechanisms underlying these adaptations,focusing on pulmonary fibrosis and hypoxia tolerance through comparative genomics and convergent evolution analyses.We observed significant expansions and contractions in certain gene families across both high-altitude and marine mammals,closely associated with processes involved in pulmonary fibrosis.Notably,members of the keratin gene family,such as KRT17 and KRT14,appear to be associated with the development of the dense elastic fiber phenotype observed in the lungs of hypoxia-tolerant mammals.Through selection pressure and amino acid substitution analyses,we identified multiple genes exhibiting convergent accelerated evolution,positive selection,and amino acid substitution in these species,associated with adaptation to hypoxic environments.Specifically,the convergent evolution of ZFP36L1,FN1,and NEDD9 was found to contribute to the high density of elastic fibers in the lungs of both high-altitude and marine mammals,facilitating their hypoxia tolerance.Additionally,we identified convergent amino acid substitutions and gene loss events associated with sperm development,differentiation,and spermatogenesis,such as amino acid substitutions in SLC26A3 and pseudogenization of CFAP47,as confirmed by PCR.These genetic alterations may be linked to changes in the reproductive capabilities of these animals.Overall,this study offers novel perspectives on the genetic and molecular adaptations of high-altitude and marine mammals to hypoxic environments,with a particular emphasis on pulmonary fibrosis.

Mammals of Gaoligong Mountain in China:Diversity,distribution,and conservation

Gaoligong Mountain(hereafter,GLGM)is located at the intersection of Myanmar and China’s Yunnan Province and Xizang Zizhiqu,and spans three globally significant biodiversity hotspots:the Himalayas,Indo-Burma,and the Mountains of Southwest China.Although surveys of mammals in this ecologically important region have a long history,there is no comprehensive systematic checklist and distribution account of the mammals of GLGM.Here,we compiled a mammal species checklist of GLGM based on thorough field investigations and literature reviews.We also examined specimen collections and applied camera trapping surveys to explore the region’s mammal diversity and distribution patterns.We recorded 212 mammal species in nine orders,33 families,and 119 genera,which accounts for 30.5%of China’s mammal species,and a high proportion of nationally protected(50)and globally threatened(29)species.Mammal species richness showed a symmetrical unimodal curve along the elevation gradient,peaking at intermediate elevations(2000 to 2500 m above sea level(asl)),and increasing generally from south to north,slightly higher in the east slope than in the west.Cluster analysis and non-metric multidimensional scaling revealed three distinct elevational assemblages(<900 m asl.,900-3500 m asl.,and>3500 m asl)and significant south-to-north variation,but no substantial differences between the east and west slopes.The GLGM present a unique conservation value due to the high proportions of rare and endangered mammal species,complex faunal composition,high endemism,and being the distribution boundary for many species.This study is an important phased account of mammal diversity in GLGM and makes a prospect for future research.

Socio-environmental factors associated with small mammal assemblage and Leptospira prevalence in Suburban Areas of Terengganu,Malaysia

Objective:To examine the socio-environmental factors associated with the assemblage of small mammals and the prevalence of Leptospira pathogen in poor suburban communities of Terengganu,Malaysia.Methods:We trapped small mammals from 119 trapping points scattered around three suburban communities of Terengganu using sausage-baited live traps.On the average,we set up five traps for three nights at each sampling point during the trapping period.Kidneys of captured animals were harvested and processed for Leptospira investigation.Additionally,environmental survey was conducted at each trapping point to obtain information about possible variables supporting small mammal assemblage.We used a generalized linear model to evaluate the effect of different socio-environmental variables on small mammals’assemblage.Results:A total of 89 small mammals,specifically,Rattus norvegicus(n=39),Rattus rattus(n=27),Rattus exulans(n=10),Suncus murinus(n=11),and Tupaia glis(n=2)were captured from 1385 trap nights.Fourteen individuals(15.7%)of the captured animals tested positive for Leptospira bacteria using PCR detection.Results of our generalized linear model showed only residences bordering vacant lots as the variable positively associated with small mammal occurrence in the three study sites.Conclusions:Small mammal community,especially the often neglected species,could harbour and potentially contribute towards pathogenic Leptospira maintenance in the study sites.To adequately control small mammals’population and subsequent human zoonoses transmission,it is critical to advocate and promote appropriate infrastructure and suburban services,together with good hygiene practices that can reduce the animals’access to food and harborage.

Clinicopathological alterations in wild mammals from the reservoir system of Trypanosoma cruzi:a scoping review

Trypanosoma cruzi is the etiologic agent of Chagas disease.This flagellated protozoan is transmitted to humans as well as different species of domestic and wild animals via vectors from the Reduviidae family(known as"kissing bugs").Despite the fact that hundreds of species of wild mammals are part of the reservoir system,the morphologi-cal changes and clinical manifestations resulting from the pathogenesis of the infection have been largely neglected.The aim of this review is to systematically compile the available information regarding clinicopathological altera-tions in wild mammals due to natural infection by T.cruzi.Information was obtained from six online bibliographic data search platforms,resulting in the identification of 29 publications that met the inclusion criteria.Mortality was the most common clinical manifestation,cardiac damage was the main finding at necropsy,and lymphoplas-macytic inflammation was the most frequent microscopic injury.Thus,regardless of its role as a reservoir,T.cruzi has the potential to affect the health status of wild mammals,a situation that highlights the need for further research to analyze,measure,and compare its effects at both the individual and population levels.

Evaluating the Impacts of Human Activities on Diversity, Abundance, and Distribution of Large Mammals in Nimule National Park, South Sudan

Globally, human activities have a significant impact on the diversity, abundance, and distribution of large mammals in Protected Areas (PAs). These disturbances increase human pressure on biodiversity and species habitats, highlighting the need for conservation. This study aimed to assess the abundance and distribution of large mammals in different habitat types within Nimule National Park (NNP) and understand the impacts of human activities on them. Data on the abundance and distribution of large mammals and their respective habitat types were collected through line transect surveys. Human activity signs were observed and recorded along the transect lines. To estimate the impacts of human activities on the diversity, abundance, and distribution of large mammal species, as well as to identify any significant differences between them and their habitat types, the study utilized the Kruskal Wallis test, Polynomial multiple regressions, and diversity indices. The findings from the Shannon-Weiner and Simpson indices indicated that large mammal species were more diverse inside the park (H’ = 1.136;D = 0.570) compared to the buffer zone (H’ = 0.413;D = 0.171), with 85% (443 out of 510 samples) recorded within Nimule National Park. The species abundance showed a semi-balanced status (0.58). The diversity results among different habitat types revealed that large mammals were more diverse and highly distributed in both open woodlands (244) and dense woodlands (192), while riverine vegetation had the lowest diversity (8). Statistical tests demonstrated a highly significant difference at a 99% confidence interval (p-value = 0.01) between habitat types and identified species of large mammals. Additionally, the results highlighted the high abundance of Uganda kob (274), baboons (141), and warthog (57) across most habitat types, accounting for at least 75% of their distribution. The most prevalent human activities observed were cattle footprints (27%) and cattle dung (14%). Human footprints and tree cutting combined accounted for 9%, indicating the practice of livestock grazing, poaching, encroachment, and fuelwood collection by local communities. However, these activities did not appear to significantly impact the diversity, abundance, and distribution of large mammals in Nimule National Park. Therefore, it is crucial to foster shared responsibilities and engage relevant stakeholders in the management and conservation of large wildlife species. Regular community awareness programs should be implemented to cultivate a sense of ownership. Moreover, it is recommended that a comprehensive survey be conducted on the population status of all mammal species in Nimule National Park, including its surrounding Buffer Zone. Monitoring the impact of human activities on their behavior and habitats using satellite images should also be carried out at least every five to ten years.

Regulation of circadian physiology and behavior by light in mammals:entrainment and masking

manifestation of circadian rhythms.The modern use of electric lights alters environmental lighting,leading to light exposure at inappropriate times to disturb circadian homeostasis for both human and wildlife.The light“pollution”and voluntary activities such as night shift work and transmeridian travelling have adverse consequences such as mood and metabolic disorders in humans.On the other hand,insufficient light exposure decreases neurotransmission from the locus ceruleus and dorsal raphe,leading to seasonal and nonseasonal affective disorders,while properly timed bright light is beneficial to mood and cognition.Given the critical and complex roles of light in mammalian physiology and behavior,it is essential to understand the underlying mechanisms.In this review,we discuss the neural mechanisms through which light regulates and dysregulates circadian rhythms in mammals.

Community Structure and Diversity Distributions of Small Mammals in Different Sample Plots in the Eastern Part of Wuling Mountains

Five years＇ （2000-2004） continuous study has been carried out on small mammals such as rodents in seven different sample plots, at three different altitudes and in six different ecological environment types in the eastern part of the Wuling Mountains, south bank of the Three Gorges of Yangtze River in Hubei. A total of 29 297 rat clamps/times were placed and 2271 small mammals such as rodents were captured, and 26 small mammals were captured by other means. All the small mammals captured belonged to 8 families 19 genera and 24 species, of which rodentia accounted for 70.83% and insectivora 29.17%. Through analysis of the data, the results showed that： 1 ） although the species richness had a trend of increasing along different sample plots as altitude increased from south to north, quite a few species showed a wide habitat range in a vertical distribution （ 15 species were dispersed over three zones and two species over two zones） , indicating a strong adaptability of small mammals such as rOdents at lower altitudes in most areas and comparatively less vertical span of entire mountains; 2） whether in seven different sample plots or six different ecological types, Apodemus agrarius and Rattus norvegicus were dominant species below 1200m, and Anourosorex squamipes, Niviventer confucianus and Apodemus draco were dominant above altitudes of 1300m, however, in quantity they were short of identical regularity, meaning they did not increase as the altitude did, or decrease as the ecological areas changed; 3）the density in winter was obviously greater than that in spring, and the distribution showed an increasing trend along with altitude, but the density in different sample plots was short of identical regularity, showing changes in different seasons and altitude grades had an important impact on small mammals such as rodents; 4） in species diversity and evenness index, there were obvious changes between the seven different sample plots, probably caused by frequent human interference in this area. Comparatively speaking, there was less human interference at high altitudes where vegetation was rich and had a high diversity and evenness index, and the boundary effect and community stability were obvious. Most ecological types have been seriously interfered with due to excessive assart at low altitudes with singular vegetation and low diversity and evenness index and poor community stability, showing an ecosystem with poor anti-reversion. If human interference can be reduced in those communities at high altitudes with low diversity and evenness index, the biological diversity in the communities will gradually recover to similar levels of other ecological areas.

Diversity of Sucking Lice on Small Mammals in the Surrounding Areas of Erhai Lake in Yunnan,China

An investigation of sucking lice on the body surface of small mammals was carried out in the surrounding areas of Erhai Lake in Dali, Yunnan from 2003 to 2004. From investigation sites, 3 303 small mammal hosts were captured and identified into 7 families, 15 genera and 21 species in 4 orders （Rodentia, Insectivora, Scandentia and Carnivora）, while t4 635 individuals of sucking lice collected from the body surface of the small mammal hosts are identified into 5 families, 6 genera and 21 species in the Order Anoplura, The sites stand alongside three cordilleras surrounding the Erhai Lake, namely Eastern Wuliang Mountain, Southern Ailao Mountain and Western Cangshan Mountain. The three confined oriented areas are different landscapes within the same zone where the longitude, latitude, altitude and fauna are homologous but isolated by Erhai Lake as inartificial barrier. The aim of this study was to recognize features of the species diversity, abundance, community structure, similarity and distribution of sucking lice in different landscapes within the same zone. The results showed the species diversity of sucking lice was very low with a very simple community structure. The distribution of sucking lice and their corresponding hosts are quite uneven among different oriented areas and this may imply that ecological environment influences the species composition and distribution of sucking lice and their corresponding hosts. A certain species of hosts usually have their fixed louse species. The similarity of sucking louse communities is highly consistent with the affinity of small mammal hosts in taxonomy. Species of sucking lice on the same small mammal host in different oriented areas of Erhai Lake are homologous. The results strongly suggest a close relationship of co-evolution between sucking lice and their hosts.

Adaptation of mammals to hypoxia

Oxygen plays a pivotal role in the metabolism and activities of mammals.However,oxygen is restricted in some environments-subterranean burrow systems or habitats at high altitude or deep in the ocean-and this could exert hypoxic stresses such as oxidative damage on organisms living in these environments.In order to cope with these stresses,organisms have evolved specific strategies to adapt to hypoxia,including changes in physiology,gene expression regulation,and genetic mutations.Here,we review how mammals have adapted to the three high-altitude plateaus of the world,the limited oxygen dissolved in deep water habitats,and underground tunnels,with the aim of better understanding the adaptation of mammals to hypoxia.

MUCOSAL IMMUNE SYSTEM AND FERTILITY REGULATION IN MAMMAL AND HUMAN

皮肤和粘膜是哺乳类动物和人体的内外环境之间的第一道屏障或第一道防线。粘膜是消化道,呼吸道和泌尿生殖道的重要组成部份。在粘膜系统大约集中了70％的淋巴组织。哺乳类动物的配子成熟,运输,精卵子的结合和融合,受精卵的运输,胚泡着床等等,都是在生殖道内进行的。因此,研究生殖道的粘膜免疫系统在不育的诊断和治疗,性传染疾病的控制,避孕疫苗的研究等方面,都有很重要的意义。 粘膜免疫系统有几个显著的特点:首先,在抗体成份方面,以IgA为主,IgA的分泌量约占全身各种抗体成份的60％以上。为了刺激粘膜的体液免疫反应,局部免疫的效果最佳。参与粘膜免疫调节的细胞有T辅助细胞,T杀伤和抑制细胞,反抑制细胞,抗抑制细胞。其次在细胞免疫方面,粘膜系统有许多TCR1 T细胞,它们在粘膜免疫方面可能具有重要的功能。粘膜系统的免疫细胞的特有分布是通过细胞表面的许多受体和配体的相互作用来实现的。雌性生殖道的粘膜免疫系统的反应常与激素水平有关,如雌二醇的升高常伴随IgA的升高,孕酮的存在常有抑制IgA产生的作用。此外,在妊娠子宫内发现有许多特殊的抑制细胞和其他许多抑制因子。 在某些不孕患者的精浆内可测定到抗精子的IgA和IgG。精浆内存在许多免疫细胞抑制因子和许多免疫细胞。

A Preliminary Survey on Diversity and Conservation Status of Medium and Large‐Sized Mammals in Weyngus Forest, West Gojjam Zone, Amhara Region, Ethiopia

Mammalian surveys are vital tools for effective managements and conservation strategies. A survey was conducted to investigate the species composition, relative abundance and to determine their major threats in Weyngus Forest, West Gojjam Zone, Amhara Region, Ethiopia. The data were collected from April 2020 to June 2020. Transect method and subjective interviews were used to collect data for the study. A total of 11 species of medium and large sized mammals belonging to six orders and eight families were recorded by direct and indirect evidences. Porcupine (Hystrix cristata), Vervet monkey (Chlorocebus aethiops), and Coloubus monkey (Colobus guereza) were among the medium-sized mammals while, Spotted hyena (Crocuta crocuta), Bushbuck (Tragelaphus scriptus) and Common duiker (Sylvicapra grimmia) were among the large-sized mammals recorded in the study area. Vervet monkey has been the most frequently observed species, whereas spotted hyena was observed less often. Simpson’s Similarity Index (SI) showed a significant overlap of mammalian species composition between scrubland and natural forest (SI = 0.62). Illegal logging of trees for fuel wood, agricultural land expansion, illegal hunting and land degradation were the main threats of mammals in the study area. Community participation and awareness creation are highly recommended to limit the impact of anthropogenic activities threatening wildlife.

全国哺乳动物多样性观测网络(China BON-Mammals)建设进展

生物多样性是人类赖以生存的条件之一,其中哺乳动物物种多样,分布范围广,对栖息地变化敏感,是生物多样性保护和环境评价的关键指示生物类群。生境的退化或丧失、自然资源的过度利用和环境污染等因素造成我国哺乳动物受到严重威胁。针对哺乳动物种群持续衰退的现状,为了掌握其生存状态、种群动态变化以及受威胁状况,环境保护部组织开展了全国大中型哺乳动物观测网络建设。重点介绍了全国哺乳动物多样性观测网络的建设目标、主要内容、红外相机观测技术和样地选择方法等,讨论了哺乳动物观测网络存在的问题及可能的解决办法,提出进一步完善全国大中型哺乳动物观测网络及信息化数据平台的建议,从而为我国生物多样性的保护管理和资源利用提供基础性数据。

A New Symmetrodont Mammal with Fur Impressions from the Mesozoic of China

Western Liaoning of northeastern China is world-renowned for the MesozoicJehol biota, especially for yielding many feathered dinosaurs, primitive birds, mammals and fossilangiosperm. This paper describes a complete specimen of a symmetrodont mammal with well-preservedhairs and soft tissue from the basal part of the Yixian Formation in the Sihetun area, Beipiao,western Liaoning. It is significant for understanding the morphology, osteology, phylogeny and lifehabits of Mesozoic symmetrodont mammals.

Diversity and distribution patterns of non-volant smallmammals along different elevation gradients on Mt. Kenya,Kenya

The distribution of small mammals in mountainous environments across different elevations can provide important information on the effects of climate change on the dispersal of species. However, few studies conducted on Afromontane ecosystems have compared the altitudinal patterns of small mammal diversity. We investigated the species diversity and abundance of non-volant small mammals(hereafter ‘small mammals')on Mt. Kenya, the second tallest mountain in Africa,using a standard sampling scheme. Nine sampling transects were established at intervals of 200 m on the eastern(Chogoria) and western(Sirimon) slopes.A total of 1 905 individuals representing 25 species of small mammals were trapped after 12 240 trap-nights.Abundance was highest at mid-elevations on both slopes.However, species richness and their distribution patterns differed between the two slopes. More species were recorded on Chogoria(24) than on Sirimon(17). On Chogoria, species richness was higher at mid-high elevations, with a peak at mid-elevation(2 800 m a.s.l.),whereas species richness showed little variation on the Sirimon slope. These results indicate that patterns of species diversity can differ between slopes on the same mountain. In addition, we extensively reviewed literature on Mt. Kenya's mammals and compiled a comprehensive checklist of 76 mammalian species. However, additional research is required to improve our understanding of smal mammal diversity in mountain habitats in Africa.

Gamma-aminobutyric acid(GABA) promotes recovery from spinal cord injury in lampreys: role of GABA receptors and perspective on the translation to mammals

In mammals, spinal cord injury (SCI) is a devastating event that can lead to a permanent loss of motor, sensory and autonomic functions below the site of injury. In the last years, the role of different neurotransmitter systems on regeneration and recovery from SCI has been deciphered. For example, studies in lampreys have shown that neurotransmitters play a key role in modulating the survival and regeneration of brainstem descending neurons after SCI (Romaus-Sanjurjo et al., 2018;Sobrido-Camean et al., 2018).

Bartonella species in small mammals and their potential vectors in Asia

In this article,authors review the current knowledge of Bartonella infection in small mammals including rodents,insectivores,bats and exotic small mammal pets and their vectors in Asia.Species of Bartonella are Gram-negative intracellular bacteria that infect erythrocytes of various mammalian and non-mammalian animals and mainly transmitted by blood sucking arthropod vectors.The genus Bartonella includes several species of important human diseases with severe clinical signs.Several new Bartonella species were isolated from rodents and other small mammals,and from human patients in Asia.Bartonella species are identified using standard polymerase chain reaction amplification and a sequencing targeting two housekeeping genes(glt.A and rpoB) and the internal transcribed spacer fragment.Authors also discuss the implications in term of potential emerging zoonotic diseases.

Inter-Regional Comparisons on the Quaternary Large Mammalian Faunas between China and Sub-Saharan Africa

The current and dominant theory about the origin of modern humans is the out-of-Africa hypothesis, which asserts that populations of Homo sapiens left Africa 100,000 years ago and replaced indigenous populations of humans in Eurasia. Many scholars equated the out-of-Africa dispersal of humans with paleoenvironmental changes. However, until now, few have paid special attention to the faunal data and whether or not faunal patterns are supportive of the popular theory. Recent comparative study of the Chinese fauna shows that the communication of faunas between Africa and East Asia could have occurred during the Neogene, but it was very limited during the Pleistocene. In the Chinese Quaternary fauna, only 16% of the genera are also present in the sub-Saharan African fauna. There is also no element among the dominant taxa of the Chinese Quaternary fauna which can be related to the African fauna. There is no reliable proof for the existence of Hippopotamus and Giraffa, as well as Panthera leo, during the Quaternary in China. Two controversial taxa are Acinonyx and Crocuta, about which there is still argument concerning their species identification in Eurasia. It is possible that both of the genera have co-specific taxa in Africa and Eurasia. Although the two genera are confined to Africa today, they did have a long evolutionary history in China. For the Out of Africa hypothesis for Homo sapiens, the implications of the limited faunal interchanges between China and Africa are not completely clear yet.

Roles of mitochondrial unfolded protein response in mammalian stem cells

The mitochondrial unfolded protein response(UPRmt)is an evolutionarily conserved adaptive mechanism for improving cell survival under mitochondrial stress.Under physiological and pathological conditions,the UPRmt is the key to maintaining intracellular homeostasis and proteostasis.Important roles of the UPRmt have been demonstrated in a variety of cell types and in cell development,metabolism,and immune processes.UPRmt dysfunction leads to a variety of pathologies,including cancer,inflammation,neurodegenerative disease,metabolic disease,and immune disease.Stem cells have a special ability to selfrenew and differentiate into a variety of somatic cells and have been shown to exist in a variety of tissues.These cells are involved in development,tissue renewal,and some disease processes.Although the roles and regulatory mechanisms of the UPRmt in somatic cells have been widely reported,the roles of the UPRmt in stem cells are not fully understood.The roles and functions of the UPRmt depend on stem cell type.Therefore,this paper summarizes the potential significance of the UPRmt in embryonic stem cells,tissue stem cells,tumor stem cells,and induced pluripotent stem cells.The purpose of this review is to provide new insights into stem cell differentiation and tumor pathogenesis.

The hypoxia adaptation of small mammals to plateau and underground burrow conditions

Oxygen is one of the important substances for the survival of most life systems on the earth,and plateau and underground burrow systems are two typical hypoxic environments.Small mammals living in hypoxic environments have evolved different adaptation strategies,which include increased oxygen delivery,metabolic regulation of physiological responses and other physiological responses that change tissue oxygen utilization.Multiomics predictions have also shown that these animals have evolved different adaptations to extreme environments.In particular,vascular endothelial growth factor(VEGF)and erythropoietin(EPO),which have specific functions in the control of O_(2) delivery,have evolved adaptively in small mammals in hypoxic environments.Naked mole-rats and blind mole-rats are typical hypoxic model animals as they have some resistance to cancer.This review primarily summarizes the main living environment of hypoxia tolerant small mammals,as well as the changes of phenotype,physiochemical characteristics and gene expression mode of their long-term living in hypoxia environment.

Diversity and habitat association of small mammals in Aridtsy forest, Awi Zone, Ethiopia

Here, we conducted a survey to examine the diversity, distribution and habitat association of small mammals from August 2011 to February 2012 incorporating both wet and dry seasons in Aridtsy forest, Awi Zone, Ethiopia. Using Sherman live traps and snap traps in four randomly selected trapping grids, namely, natural forest, bushland, grassland and farmland, a total of 468 individuals comprising eight species of small mammals（live traps） and 89 rodents of six species（snap traps） were trapped in 2352 and 1200 trap nights, respectively. The trapped small mammals included seven rodents and one insectivore： Lophuromys flavopuntatus（30.6%）, Arvicanthis dembeensis（25.8%）, Stenocephalemys albipes（20%）, Mastomys natalensis（11.6%）, Pelomys harringtoni（6.4%）, Acomys cahirinus（4.3%）, Lemniscomys zebra（0.2%） and the greater red musk shrew（Crocidura flavescens, 1.1%）. Analysis showed statistically significant variations in the abundance and habitat preferences of small mammals between habitats during wet and dry seasons.