During the Late Miocene,numerous medium to large-sized herbivores,that resemble the living Ovibos in skeletal morphology,dispersed throughout the Holarctic realm and comprised eleven genera:Lantiantragus,Shaanxispira,...During the Late Miocene,numerous medium to large-sized herbivores,that resemble the living Ovibos in skeletal morphology,dispersed throughout the Holarctic realm and comprised eleven genera:Lantiantragus,Shaanxispira,Tsaidamotherium,Criotherium,Mesembriacerus,Hezhengia,Urmiatherium,Parurmiatherium,Plesiaddax,Sinotragus,and Prosinotragus.These genera are primarily found in eastern Asia,in which nine genera are found in northern China,as well as in countries in eastern Europe and western Asia.They are distinguished by unique characteristics,including a perpendicular braincase,specialized horn cores,and a robust basioccipital.Previous studies have often classified these‘ovibovin’bovids as part of the conventional subfamily/tribe Ovibovinae/Ovibovini,along with extant Ovibos.Nevertheless,an increasing number of studies do not support the monophyly of the subfamily/tribe Ovibovinae/Ovibovini,nor is a close relationship likely between these Late Miocene‘ovibovin’bovids and extant Ovibos.Among the eleven genera of‘ovibovin’bovids,Plesiaddax,Hezhengia,and Urmiatherium are often considered to have a very close relationship and conventionally form the tribe Urmiatheriini.However,previous phylogenetic analyses do not support the monophyly of Urmiatheriini.This paper presents a summary of the transmutation of the terms Ovibovidae/Ovibovinae/Ovibovini/Ovibovina,the temporal and spatial distribution of the Late Miocene‘ovibovin’bovids in Eurasia,the principal characteristics of these taxa,and the previous phylogenetic analyses.展开更多
Xanthine oxidoreductase (XOR) is a molybdoflavoprotein mainly involved in purine catabolism. It exists in two forms, the oxidase (XO) and dehydrogenase (XDH) which are inter-convertible within mammalian cells. Althoug...Xanthine oxidoreductase (XOR) is a molybdoflavoprotein mainly involved in purine catabolism. It exists in two forms, the oxidase (XO) and dehydrogenase (XDH) which are inter-convertible within mammalian cells. Although various researchers have reported the extraction of mammalian XOR, no extractions have yet been carried out in Malta and subsequently no characterizations are available. In this study, XOR was successfully purified from bovine, caprine and ovine milk through a multistep purification process involving both chemical and chromatographic techniques. The molecular weights of the native enzyme were found to be 295 kDa, 281 kDa and 275 kDa, representing the bovine, caprine and ovine XOR respectively. Western blot showed XOR to be represented on SDS-PAGE by a minimum of three major bands having molecular weights of 151 kDa, 131 kDa and 85 kDa. While all samples showed activity on native PAGE, spectrophotometric assays revealed the bovine XOR to be the most active. Surprisingly, the addition of NAD+ to the assay mixture inhibited enzyme activity of the bovine and caprine XOR whereas the ovine XOR doubled its activity in response to NAD+. The latter also showed a lower binding affinity to heparin. Following incubation with trypsin, XOR was irreversibly converted to its oxidase form in all samples as reflected by the observed increase in XO activity.展开更多
Conspicuous coloration in animals serves many functions such as anti-predation.Anti-predation strategies include motion dazzle and flash behavior.Motion dazzle markings can reduce the probability of being preyed on be...Conspicuous coloration in animals serves many functions such as anti-predation.Anti-predation strategies include motion dazzle and flash behavior.Motion dazzle markings can reduce the probability of being preyed on because the predators misjudge their movement.In flash behavior,prey demonstrate conspicuous cue while fleeing;the predators follow them;however,the prey hide their markings and the predators assume that the prey has vanished.To investigate whether bovids use conspicuous hindquarter markings as an anti-predatory behavior,we undertook phylogenetically controlled analyses to explore under what physiological characteristics and environmental factors bovids might have this color pattern.The results suggested that rump patches and tail markings were more prevalent in bovids living in larger-sized groups,which supports the hypothesis of intraspecific communication.Moreover,we observed the occurrence of conspicuous white hindquarter markings in bovids having smaller body size and living in larger groups,suggesting a motion dazzle function.However,the feature of facultative exposing color patterns(flash markings)was not associated with body size,which was inconsistent with predictions and implied that bovids may not adopt this as an anti-predator strategy.It was concluded that species in bovids with conspicuous white hindquarter markings adopt motion dazzle as an anti-predation strategy while fleeing and escaping from being prey on.展开更多
文摘During the Late Miocene,numerous medium to large-sized herbivores,that resemble the living Ovibos in skeletal morphology,dispersed throughout the Holarctic realm and comprised eleven genera:Lantiantragus,Shaanxispira,Tsaidamotherium,Criotherium,Mesembriacerus,Hezhengia,Urmiatherium,Parurmiatherium,Plesiaddax,Sinotragus,and Prosinotragus.These genera are primarily found in eastern Asia,in which nine genera are found in northern China,as well as in countries in eastern Europe and western Asia.They are distinguished by unique characteristics,including a perpendicular braincase,specialized horn cores,and a robust basioccipital.Previous studies have often classified these‘ovibovin’bovids as part of the conventional subfamily/tribe Ovibovinae/Ovibovini,along with extant Ovibos.Nevertheless,an increasing number of studies do not support the monophyly of the subfamily/tribe Ovibovinae/Ovibovini,nor is a close relationship likely between these Late Miocene‘ovibovin’bovids and extant Ovibos.Among the eleven genera of‘ovibovin’bovids,Plesiaddax,Hezhengia,and Urmiatherium are often considered to have a very close relationship and conventionally form the tribe Urmiatheriini.However,previous phylogenetic analyses do not support the monophyly of Urmiatheriini.This paper presents a summary of the transmutation of the terms Ovibovidae/Ovibovinae/Ovibovini/Ovibovina,the temporal and spatial distribution of the Late Miocene‘ovibovin’bovids in Eurasia,the principal characteristics of these taxa,and the previous phylogenetic analyses.
文摘Xanthine oxidoreductase (XOR) is a molybdoflavoprotein mainly involved in purine catabolism. It exists in two forms, the oxidase (XO) and dehydrogenase (XDH) which are inter-convertible within mammalian cells. Although various researchers have reported the extraction of mammalian XOR, no extractions have yet been carried out in Malta and subsequently no characterizations are available. In this study, XOR was successfully purified from bovine, caprine and ovine milk through a multistep purification process involving both chemical and chromatographic techniques. The molecular weights of the native enzyme were found to be 295 kDa, 281 kDa and 275 kDa, representing the bovine, caprine and ovine XOR respectively. Western blot showed XOR to be represented on SDS-PAGE by a minimum of three major bands having molecular weights of 151 kDa, 131 kDa and 85 kDa. While all samples showed activity on native PAGE, spectrophotometric assays revealed the bovine XOR to be the most active. Surprisingly, the addition of NAD+ to the assay mixture inhibited enzyme activity of the bovine and caprine XOR whereas the ovine XOR doubled its activity in response to NAD+. The latter also showed a lower binding affinity to heparin. Following incubation with trypsin, XOR was irreversibly converted to its oxidase form in all samples as reflected by the observed increase in XO activity.
基金This study received support from the Tibet Major Science and Technology Project(XZ201901-GA-06).
文摘Conspicuous coloration in animals serves many functions such as anti-predation.Anti-predation strategies include motion dazzle and flash behavior.Motion dazzle markings can reduce the probability of being preyed on because the predators misjudge their movement.In flash behavior,prey demonstrate conspicuous cue while fleeing;the predators follow them;however,the prey hide their markings and the predators assume that the prey has vanished.To investigate whether bovids use conspicuous hindquarter markings as an anti-predatory behavior,we undertook phylogenetically controlled analyses to explore under what physiological characteristics and environmental factors bovids might have this color pattern.The results suggested that rump patches and tail markings were more prevalent in bovids living in larger-sized groups,which supports the hypothesis of intraspecific communication.Moreover,we observed the occurrence of conspicuous white hindquarter markings in bovids having smaller body size and living in larger groups,suggesting a motion dazzle function.However,the feature of facultative exposing color patterns(flash markings)was not associated with body size,which was inconsistent with predictions and implied that bovids may not adopt this as an anti-predator strategy.It was concluded that species in bovids with conspicuous white hindquarter markings adopt motion dazzle as an anti-predation strategy while fleeing and escaping from being prey on.
文摘微卫星(simples equencere peats, SSRs)广泛分布于生物基因组中,是最常用的分子标记之一。本研究利用生物信息学方法搜索和统计了7种牛科动物转录组中完整型SSRs序列,揭示不同重复类型SSRs变异水平,并对其生物信息学特征进行比较分析。在牛科动物转录组中,牛、绵羊和山羊SSRs总丰度较高,三者基本一致(157.98, 157.09 vs 158.52个/Mb);其次是瘤牛和水牛(140.70 vs 129.63个/Mb);牦牛微卫星总丰度较低(96.99个/Mb),藏羚羊微卫星总丰度最低(63.71个/Mb)。牛科动物转录组中SSRs所占比例普遍偏低,范围为0.156%~0.753%,三碱基SSRs占主导地位,并且以(CCG)n和(AGG)n为优势重复基元,这可能与转录组编码区三联体密码子高度保守有关。在这7种牛科动物转录组中,相同单碱基至六碱基SSRs重复拷贝数(repeat copy number, RCN)分布高度一致。通过牛科动物转录组SSRs变异系数(coefficient of variability, CV)分析表明,单碱基SSRs和二碱基SSRs重复拷贝数变异水平较高,其次RCN变异模式如下:三碱基SSRs>四碱基SSRs>六碱基SSRs>五碱基SSRs,六碱基SSRs重复拷贝数变异水平有稍微增加的趋势。本研究为牛科动物SSR标记的开发、遗传多样性评估和遗传育种提供科学依据。
