Fossil evidence for evolution of the shape and color of penguin feathers

Penguin feathers are highly modified in form and function, but there have been no fossils to inform their evolution. A giant penguin with feathers was recovered from the late Eocene (~36 million years ago) of Peru. The fossil reveals that key feathering features, including undifferentiated primary wing feathers and broad body contour feather shafts, evolved early in the penguin lineage. Analyses of fossilized color-imparting melanosomes reveal that their dimensions were similar to those of non-penguin avian taxa and that the feathering may have been predominantly gray and reddish-brown. In contrast, the dark black-brown color of extant penguin feathers is generated by large, ellipsoidal melanosomes previously unknown for birds. The nanostructure of penguin feathers was thus modified after earlier macrostructural modifications of feather shape linked to aquatic flight.     

A diverse assemblage of Late Cretaceous dinosaur and bird feathers from Canadian amber

The fossil record of early feathers has relied on carbonized compressions that lack fine structural detail. Specimens in amber are preserved in greater detail, but they are rare. Late Cretaceous coal-rich strata from western Canada provide the richest and most diverse Mesozoic feather assemblage yet reported from amber. The fossils include primitive structures closely matching the protofeathers of nonavian dinosaurs, offering new insights into their structure and function. Additional derived morphologies confirm that plumage specialized for flight and underwater diving had evolved in Late Cretaceous birds. Because amber preserves feather structure and pigmentation in unmatched detail, these fossils provide novel insights regarding feather evolution.     

朝鲜鹌鹑GNAS基因表达、克隆及其多态性与羽色的相关性

为了研究朝鲜鹌鹑GNAS基因表达和多态性与羽色的相关性,取栗羽和白羽朝鲜鹌鹑不同发育时期胚胎翅尖组织,采用Trizol法提取总RNA,实时荧光定量PCR检测GNAS基因在朝鲜鹌鹑胚胎发育不同阶段和不同羽色鹌鹑胚胎翅组织中mRNA的表达水平;克隆GNAS基因的CDS全序列并进行生物信息学分析;采集孵化至10 d胚胎翅尖组织提取基因组DNA,PCR扩增GNAS基因的特定序列,通过不对称PCR-SSCP方法结合测序确定基因型,分析不同基因型对朝鲜鹌鹑羽色形成的影响。结果表明,胚胎发育8~14 d时,GNAS基因在栗羽鹌鹑胚胎组织中的表达水平极显著(P<0.01)高于白羽鹌鹑胚胎。GNAS基因CDS区开放阅读框长1 140 bp,含有14个外显子,编码含379个氨基酸的稳定性亲水蛋白。在朝鲜鹌鹑GNAS基因中检测到2个SNP位点,分别为外显子12区域的g.119221T>A和3'UTR区域的g.121181A>G。栗羽朝鲜鹌鹑的3种基因型(AA、 AB和BB)的频率分布与白羽朝鲜鹌鹑存在极显著差异(P<0.01)。结论表明,朝鲜鹌鹑组织中GNAS基因的表达量高低与其羽色的形成有一定的关系,GNAS基因3'UTR上的g.121181A>G位点突变与朝鲜鹌鹑羽色性状之间具有显著关联性,可作为研究朝鲜鹌鹑羽色的一个候选基因。     

Regional specialization of reptilian scale surfaces: relation of texture and biologic role

The iridescent body scales of the fossorial uropeltid snakes produce these interference colors by keratinous ridges spaced at 2500 A. The pattern inhibits wetting of the surface and adhesion of soil particles and thus reduces friction between the snake's trunk and walls of its tunnel. The epidermal scales of the blunt tail show a sharply defined pattern of spines and ridges with convergent flutings. Dirt caught here forms a plug that protects the snake's caudal end. The sharp transition of surface textures suggests (i) that selection for each of the two roles is great, and (ii) that the interference colors of many fossorial snakes indicate that friction as well as dirt adhesion are being reduced.     

固始鸡慢羽系胫色、羽色与羽毛生长变化规律研究

观测了固始鸡慢羽系胫色、羽色的变化规律及羽毛生长情况。结果表明 :随着周龄的增加 ,胫色由浅色向深色转变 ;而羽色则由深色向浅色转变。固始鸡慢羽系部分公鸡 6周龄已有明显的性征表现 ,此时鸡冠发育清楚可辨 ,羽色鲜艳、亮丽 ,且多为红棕黄羽。从 9日龄开始 ,雏鸡绒羽依次从颈部、胸部换羽 ,30日龄左右开始部分长尾羽。     

鹅伴性羽色性状的遗传分析

【目的】 豁眼鹅是我国著名的白鹅品种,其1日龄雏鹅往往呈现黄色或淡黄色。然而,笔者在进行豁眼鹅纯系继代选育过程中,发现自由交配群体的后代中有20%雏鹅个体绒羽呈现浅褐色,且公母比例差别明显（公母比例接近1﹕3）,推测豁眼鹅群体白羽性状存在伴性遗传可能。以雏鹅期浅褐色公鹅和黄色母鹅为亲本,利用杂交试验,检验雏鹅绒羽表型的情况是否符合孟德尔遗传规律,从而揭示鹅羽色性状的遗传方式。为此开展鹅的羽色性状遗传规律及机制研究,以期对鹅新品种或品系的培育以及鹅羽色自别雌雄配套系生产提供指导。【方法】 选用40只豁眼鹅公鹅和200只豁眼鹅母鹅为亲本,组建随机交配群产生豁眼鹅纯系G₁代,观察G₁代中1日龄雏鹅中黄色绒羽和浅褐色绒羽表型的表现和分离比例;4只浅褐色豁眼鹅公鹅和20只黄色豁眼鹅母鹅为亲本,杂交产生F₁代,观察其1日龄雏鹅中黄色绒羽和浅褐色绒羽表型的表现和分离比例。【结果】 ①在豁眼鹅随机交配G₁代中,浅褐色绒羽表型个体的比例为19.5%。其中,公母雏之间浅褐色个体占比差别比较大,公雏中浅褐色的比例在10%左右,而母雏有30%左右的个体呈现浅褐色。根据Hardy-Weinberg定律,绒羽颜色性状等位基因频率计算如下,母雏中浅褐色个体的比例就是豁眼鹅群体中绒羽浅褐色等位基因的频率,本试验中29.8%的母雏个体是呈现浅褐色,所以该等位基因的频率约为0.3。同时,公雏中浅褐色个体比例的开方也能计算出豁眼鹅群体中浅褐色等位基因的频率,本例中,10%的公雏是浅褐色,所以该等位基因的频率约为0.3左右,同母雏计算所得基因频率比较接近。相应的,绒羽黄色等位基因频率则为0.7左右。②杂交F₁中,黄羽81只,占50%;浅褐色79只,占50%。且黄羽全为公雏,浅褐色羽全是母雏。结果表明,浅褐色性状呈伴性遗传;已研究证实,银色羽（S*S）和不完全白化（S*AL）是位于Z染色体上的一对等位基因控制,不完全白化基因AL对银色羽基因S为隐性。因此,根据杂交试验结果,可以初步判断浅褐色和黄色是由一个基因座的复等位基因所决定的结果,且浅褐色对于黄色性状呈隐性遗传。【结论】 本试验通过羽色性状选配杂交和随机交配试验,分析了豁眼鹅1日龄雏鹅绒羽颜色表型的分离情况,结果表明：（1）浅褐色绒羽性状相对黄色绒羽性状为隐性遗传;（2）豁眼鹅雏鹅绒羽浅褐色/黄色性状呈伴性遗传;（3）豁眼鹅雏鹅绒羽颜色性状主要为Z染色体银色羽基因座控制,控制该基因座的等位基因存在变异位点与相应表型关联。     

四川白鹅活体拔毛产毛绒量测定

从四川白鹅种群中抽取试验鹅106只，分别进行“成年公鹅常年拔毛”、“种鹅体产期拔毛”、“种鹅育成期投毛”及“肉鸽一次性拔毛”四个试验．除“成年公鹅常年拔毛”试验不设对用外，其余备试验均设对照。试验结果表明成年公鹅一年可拔毛8次，平均每只一年获得毛绒736．7克．种鹅休产期拔毛二次，平均每只获毛纺157．2克，休产期拔毛对其体重和产蛋性能并无不良影响。种鹅育成期拔毛二次，平均每只获得毛绒111．3克，对有成期生长发育未见不良影响。肉鹅一次性拔毛虽然每只可获得毛绒50．9克，但拔毛后要饲养25天以上方好出售，结果毛绒收入不延长饲养期支出，因此没有推广价值。     

不同LED光色对雪山鸡生长性能·鸡冠发育和啄羽行为的影响

[目的]研究不同LED光色对雪山鸡生长性能、鸡冠发育和啄羽行为的影响。[方法]试验采用LED暖红灯、蓝绿灯和暖黄灯对46日龄雪山鸡进行24 h照明,持续35 d,然后测定鸡群的生长性能、鸡冠发育和啄羽情况。[结果]不同光色下3组雪山鸡的体重无显著差异(P0.05);蓝绿组雪山鸡的冠高显著大于暖红组和暖黄组(P0.05);3组雪山鸡的冠长差异不显著(P0.05);3组雪山鸡的鸡冠红度评价差异不大;蓝绿组雪山鸡的啄羽比例远低于暖红组和暖黄组。[结论]LED蓝绿灯可在雪山鸡饲养中推广应用。     

Trace metals as biomarkers for eumelanin pigment in the fossil record

Well-preserved fossils of pivotal early bird and nonavian theropod species have provided unequivocal evidence for feathers and/or downlike integuments. Recent studies have reconstructed color on the basis of melanosome structure; however, the chemistry of these proposed melanosomes has remained unknown. We applied synchrotron x-ray techniques to several fossil and extant organisms, including Confuciusornis sanctus, in order to map and characterize possible chemical residues of melanin pigments. Results show that trace metals, such as copper, are present in fossils as organometallic compounds most likely derived from original eumelanin. The distribution of these compounds provides a long-lived biomarker of melanin presence and density within a range of fossilized organisms. Metal zoning patterns may be preserved long after melanosome structures have been destroyed.     

川东大黑鸡测交羽色研究

试验选用青脚白羽鸡作母本,川东大黑鸡作父本进行测交,结果表明,以青脚白羽鸡作母本、川东大黑鸡作父本的测交组合经济性状效果较好,对其测交的羽色遗传效应较复杂,对丰富遗传育种理论和指导育种实践有着重要的意义。     

半番鸭羽色相关基因均一化差减文库的构建和鉴定

【目的】分离半番鸭羽色相关基因,探索半番鸭羽色基因表达调控的分子机制。【方法】以半番鸭白羽皮肤和黑羽皮肤分别作为试验组（tester）和驱动组（driver）,利用双链特异性核酸酶（duplexspecific nuclease,DSN）介导的均一化消减杂交方法,构建半番鸭羽色相关基因消减cDNA文库,同时采用实时荧光定量PCR方法对文库质量进行验证。【结果】①从文库中随机选取144个阳性克隆进行测序分析,最终共获得64条有效序列,平均长度为1 031 bp;经BLAST比对发现,21条具有同源序列,且同源性平均为92.8%;43条未找到匹配序列,推测可能为羽色相关新基因;②Geneontology功能分析表明,已知基因参与信号转导、细胞结构、物质转运、细胞凋亡、细胞与机体防御、转录与表达调控等诸多生物学过程,并且与色素形成和转运存在不同程度的相关性。【结论】经实时荧光定量PCR鉴定后,所建文库质量良好,能够有效地富集白羽皮肤特异表达基因。     

麒麟鸡(翻毛鸡)外貌性状和生长性能研究

[目的]研究麒麟鸡羽毛生长变化特点以及测定1~12周龄麒麟鸡的生长性能。[方法]对胚胎期8日龄至7周龄麒麟鸡的羽毛生长发育过程进行分析,并对1~12周龄麒麟鸡生长性能进行研究。[结果]麒麟鸡羽毛主要有黄、白和麻3种颜色,在胚胎期12日龄开始出现绒毛,出壳后第1周龄出现羽毛翻卷现象,第7周龄完成全身羽毛的翻卷;麒麟鸡公鸡生长速度比母鸡快,1日龄公、母鸡体重相近,分别为37.02 g和34.28 g,差异不显著(P0.05),而12周龄公、母鸡体重分别为1 598.01 g和1 324.57 g,存在显著差异(P0.05)。[结论]麒麟鸡羽毛翻卷独具特色,其生长速度快,生长性能高,能够为其作为特色优质肉鸡的开发利用提供理论依据。     

Rediscovery of the yellow-fronted gardener bowerbird

The long-lost bowerbird Amblyornis flavifrons was found in the Foja Mountains of west New Guinea, and its bower and display were discovered. The bower is a stick tower on a rimmed moss platform, adorned with separate piles of fruit of three different colors. The displaying male extends toward the female a blue fruit set against his golden crest. These observations support a derivation of bower ornamentation from ritual courtship feeding and a transfer of ornamentation from the male's plumage to the bower.     

Climate-driven range expansion and morphological evolution in a marine gastropod

Little is known about the phenotypic consequences of global climate change, despite the excellent Pleistocene fossil record of many taxa. We used morphological measurements from extant and Pleistocene populations of a marine gastropod (Acanthinucella spirata) in conjunction with mitochondrial DNA sequence variation from living populations to determine how populations responded phenotypically to Pleistocene climatic changes. Northern populations show little sequence variation as compared to southern populations, a pattern consistent with a recent northward range expansion. These recently recolonized northern populations also contain shell morphologies that are absent in extant southern populations and throughout the Pleistocene fossil record. Thus, contrary to traditional expectations that morphological evolution should occur largely within Pleistocene refugia, our data show that geographical range shifts in response to climatic change can lead to significant morphological evolution.     

Self-assembly of ordered microporous materials from rod-coil block copolymers

Rod-coil diblock copolymers in a selective solvent for the coil-like polymer self-organize into hollow spherical micelles having diameters of a few micrometers. Long-range, close-packed self-ordering of the micelles produced highly iridescent periodic microporous materials. Solution-cast micellar films consisted of multilayers of hexagonally ordered arrays of spherical holes whose diameter, periodicity, and wall thickness depended on copolymer molecular weight and composition. Addition of fullerenes into the copolymer solutions also regulated the microstructure and optical properties of the microporous films. These results demonstrate the potential of hierarchical self-assembly of macromolecular components for engineering complex two- and three-dimensional periodic and functional mesostructures.     

快慢羽鸡的翼羽长度与相关基因表达分析

PRLR和SPEF2基因重复是鸡快慢羽表型的分子基础，为探究羽型的分子调控机制，本试验量测了19和21胚龄（E）的快慢羽坝上长尾鸡和太行鸡主翼羽和覆主翼羽长度，采用RT-qPCR检测鸡胚翅羽PRLR、SPEF2、BMP2和FST的表达变化。结果显示19E时坝上长尾慢羽鸡主翼羽比覆主翼羽长1.35 mm(P<0.05)，慢羽表型不明显；而此时太行慢羽鸡主翼羽长于覆主翼羽0.42 mm(P>0.05)，慢羽表型明显。PRLR和SPEF2在2个品种慢羽鸡的表达均显著高于快羽鸡（P<0.05），分别在1.4和2.0倍以上；SPEF2在21E坝上长尾快慢羽鸡表达均显著高于19E(P<0.05)。BMP2表达在坝上长尾慢羽鸡中显著高于快羽鸡（P<0.05），而在不同胚龄太行快慢羽鸡中则无显著差异（P>0.05）;FST在19E坝上长尾慢羽鸡中表达量最低（P<0.05），而太行鸡19E的慢羽鸡表达量最高（P<0.05）。综上，太行鸡在19E已表现慢羽表型，而坝上长尾鸡的慢羽表型在21E才呈现；推测PRLR和SPEF2在慢羽翅羽毛囊中的高表达，以及BMP2和FST在太行鸡和坝上长尾鸡翅羽毛囊中的差异表达，参与慢羽表型的形成。本试验的研究发现为阐明鸡羽型形成的分子调控提供理论依据。     

Extreme reversed sexual dichromatism in a bird without sex role reversal

Brilliant plumage is typical of male birds, reflecting differential enhancement of male traits when females are the limiting sex. Brighter females are thought to evolve exclusively in response to sex role reversal. The striking reversed plumage dichromatism of Eclectus roratus parrots does not fit this pattern. We quantify plumage color in this species and show that very different selection pressures are acting on males and females. Male plumage reflects a compromise between the conflicting requirements for camouflage from predators while foraging and conspicuousness during display. Females are liberated from the need for camouflage but compete for rare nest hollows.     

Wright's shifting balance theory: an experimental study

Experimental confirmation of Wright's shifting balance theory of evolution, one of the most comprehensive theories of adaptive evolution, is presented. The theory is regarded by many as a cornerstone of modern evolutionary thought, but there has been little direct empirical evidence supporting it. Some of its underlying assumptions are viewed as contradictory, and the existence and efficacy of the theory's fundamental adaptive process, interdemic selection, is the focus of controversy. Interdemic selection was imposed on large arrays of laboratory populations of the flour beetle Tribolium castaneum in the manner described by Wright: the differential dispersion of individuals from demes of high fitness into demes of low fitness. A significant increase in average fitness was observed in the experimental arrays when compared to control populations with equivalent but random migration rates. The response was not proportional to the selection differential: The largest response occurred with interdemic selection every two generations rather than every generation or every three generations. The results indicate that the interdemic phase of Wright's shifting balance theory can increase average fitness and suggest that gene interactions are involved in the observed response.     

Ancient bisexual flowers

Fossil flowers discovered in 94-million-year-old clays of the Dakota Formation in Nebraska are among the earliest known demonstrably bisexual flowers. The flowers are of medium size and have pentamerous whorls of clearly differentiated floral parts, petals alternate with the sepals, short stamens are borne opposite the petals, the carpels are fused, and a receptacular disk is present. The pollen is small and tricolporate. These flowers appear to be well adapted to insect pollination. The numerous floral features and pollen characters provide sufficient diagnostic data to assess its systematic position. No extant order accommodates the features of this flower and it shares some features of various extant orders. The classification of flowering plants and our understanding of their evolution must be influenced by the fossilized remains of ancient flowers.     

Feather quill knobs in the dinosaur Velociraptor

Some nonavian theropod dinosaurs were at least partially covered in feathers or filamentous protofeathers. However, a complete understanding of feather distribution among theropod dinosaurs is limited because feathers are typically preserved only in lagerst?tten like that of Solnhofen, Germany or Liaoning, China. Such deposits possess clear taphonomic biases toward small-bodied animals, limiting our knowledge regarding feather presence in larger members of feathered clades. We present direct evidence of feathers in Velociraptor mongoliensis based on the presence of quill knobs on the posterior forearm. This report of secondaries in a larger-bodied, derived, and clearly flightless member of a nonavian theropod clade represented by feathered relatives is a substantial contribution to our knowledge of the evolution of feathers.