Functional indispensability of fibronectin associated on the mesenchymal cell surface during the early period of feather development in the chick embryo in vitro

To clarify the role of fibronectin (FN) during the early period of feather development, reconstituted skin consisting of intact epithelium and isolated mesenchymal cells from embryonal chick skin was used. In early feather development, FN was localized around mesenchymal cells of the dermal condensation. Isolated mesenchymal cells had associated with FN on their surfaces. FN on the cell surface dissociated following EDTA treatment, and EDTA‐treated cells re‐associated with exogenous FN. The intact epithelium also bound to exogenous FN at the placode. When FN‐associated or FN‐reassociated mesenchymal cells were used, the reconstituted skin formed feather rudiments only at the positions where the epithelial placode existed originally, and the locality of tenascin transferred from the placode to the mesenchyme during the period of feather bud formation. However, in reconstituted skin using FN‐dissociated mesenchymal cells, feather rudiments did not form. Additionally, the epithelial placodes disappeared, and tenascin was distributed uniformly on the surface of the epithelium and not localized in the mesenchyme. These findings suggest that FN associated on the surfaces of mesenchymal cells maintains the functions of mesenchymal cells as dermal condensation and mediates epithelial‐mesenchymal interactions during the early period of feather development. The results also suggest that reconstituted skin is a useful tool for functional studies on the extracellular matrix.     

红腹锦鸡胚胎期羽毛芽发育的研究

旨在了解红腹锦鸡胚胎期羽毛毛囊的组织结构及毛囊形态发生的变化过程,为研究红腹锦鸡羽毛毛囊发育的分子调控机理奠定组织学基础。分别对5、7、8、9、10、11、13、16、18日胚龄的红腹锦鸡胚胎发育情况进行实体观察;采集上述胚龄的红腹锦鸡背部皮肤,制作石蜡切片并进行HE染色,在显微镜下观察毛囊形态结构并拍照记录。红腹锦鸡胚胎于9日胚龄时羽毛芽开始发育,可以观察到色素在毛囊内的沉积,16日胚龄时毛囊发育基本完成,体表覆盖羽毛。该研究为进一步阐明红腹锦鸡羽毛发育的分子机制奠定了组织学基础。     

Extraction and characterization of collagens from yak rumen smooth muscle

This study reports an effective method using enzymatic methods to extract collagen from yak rumen smooth muscle. The enzymatic extraction methods were optimized by response surface methodology. Additionally, the properties of the extracted collagen were analyzed by Fourier transform infrared (FT‐IR) spectroscopy and mass spectrometry (MS). The results showed that the optimal conditions were as follows: the pepsin addition was 0.95%, the enzymatic hydrolysis time was 21 hr, and the solid‐to‐solvent ratio was 1:11. Under these conditions, the collagen extraction rate could reach 3.62/100 g. The results of FT‐IR revealed that the amide A, amide B, amide I, amide II, and amide III bands of the collagen appeared at 3,293.18, 3,068.18, 1654.94, 1,540.58, and 1,236.58 cm^?1, respectively. The MS identified seven types of collagen, which were type I, type III, type IV, type V, type VI, type VIII, and type XII. The results demonstrated that the enzymatic method can extract collagen from yak rumen smooth muscle with a considerably high yield and can preserve the intact structure of the collagen.     

Postnatal development of the mouse volatile papilla taste bud cells

In the present study, we examined specific markers for taste bud cells in the mouse and the postnatal development of volatile papilla taste bud cells in ddY mice. We examined the immunoreactivity of 4 types of carbonic anhydrase isoenzymes, CA I, CA II, CA III and CA VI, as specific markers for taste bud cells, and K8.13 cytokeratin antibody as a specific marker for the lingual epithelial cells. Of the carbonic anhydrase isoenzymes, only CA III immunoreactivity was clearly detected in the spindle shaped gustatory cells. CA VI immunoreactivity was detectable in suspentacular cells. CA I and CA II antibodies did not recognize any taste bud cell specifically. K8.13 cytokeratin immunoreactivity was detected in the lingual epithelial cells, but not in taste bud cells. At 7 days after birth, the suckling phase, very small taste buds developed from the anaplastic gustatory cells. At 14 days after birth, the taste buds showed larger size than those at 7 days after birth. At 21 days birth, after the weaning phase, taste bud structure approximated the mature structure. These results demonstrate the specificity of anti-CA III and anti-CA VI for gustatory cells and suspentacular cells, respectively. These markers should be useful for an analysis of taste bud development in mice.     

鸡皮肤毛囊生长差异基因的生物信息学分析

【目的】 筛选鸡胚胎早期发育期间背部皮肤上皮和间充质中调控毛囊生长的关键基因、生物过程和信号通路,为了解鸡胚胎早期发育期间毛囊生长的分子机制提供参考。【方法】 从GEO数据库中下载基因芯片GSE62882数据集,采用R语言limma包对数据集进行差异分析,分别筛选出胚胎期第7和9天皮肤上皮和间充质差异基因以及皮肤上皮和间充质共同上下调基因,通过STRING在线数据库对差异基因和共同上下调基因进行蛋白互作网络分析,用Cytoscape 3.8.2软件进行可视化,运用R语言中的clusterProfiler程序包对差异基因和共同上下调基因进行GO功能和KEGG通路富集分析。【结果】 皮肤上皮在胚胎期第7和9天共筛选出626个差异基因,获得189条相互作用关系、10个生物过程和4条信号通路;皮肤间充质在胚胎期第7和9天共筛选出690个差异基因,获得326条相互作用关系、10个生物过程和3条信号通路;皮肤上皮和间充质在胚胎期第7和9天共同上调基因26个,共同下调基因48个,共同上下调基因存在34条相互作用关系,主要富集在Wnt信号通路上。【结论】 本研究从鸡胚胎期第7和9天皮肤上皮和间充质中筛选到共同上调基因26个,共同下调基因48个,这些基因主要富集在Wnt信号通路上,为探究上皮和间充质在毛囊生长发育中的作用机制提供理论参考。     

牛胚胎角芽组织基因表达特征分析

[目的] 通过基因表达特征的分析,揭示在形成牛胚胎角芽组织中起关键作用的基因和通路,从而更深入地了解角芽发育过程中的分子机制。[方法] 基于牛胚胎角芽组织、额部皮肤组织、脑、心脏、肾、肝脏、肺、瘤胃、骨骼肌、脾脏的转录组测序数据,利用主成分分析(PCA)、差异表达基因分析和基因富集分析来解析角芽组织的基因表达特征。 [结果] 多组织基因表达比较鉴定到810个角芽组织特异高表达基因。主成分分析表明牛胚胎角芽组织与额部皮肤组织的基因表达模式最为相似,但存在1695个显著上调基因（校正p<=0.05), 这些基因功能富集到与神经和骨发育相关的通路。[结论] 从多组织比较、角芽组织和额部皮肤的差异比较两个方面分别鉴定了角芽组织的基因表达特征,角芽组织特异高表达基因富集到骨、神经和皮肤发育相关通路,暗示着角芽组织发育涉及多组织协同,具有复杂的调控机制。     

The lingual taste buds of Gallus domesticus L

The so‐called “ taste buds “ of the chicken were examined. It was found that they had one or more pores and were composed of a single cell type. There was a nerve plexus at the base of the bud giving rise to fibres which entered the bud. The cells showed acetyl cholinesterase activity and were found to degenerate following denervation. Thus they closely parallel, in both structure and neural dependency, the taste buds in other vertebrates and it is concluded that they probably are true taste buds.     

北京油鸡快慢羽公鸡鉴定及羽毛发育、生长和繁殖性能的对比分析

试验通过开展快慢羽群体的鉴定,并对比其在羽毛发育、生长和繁殖性能方面的差异,旨在为北京油鸡种鸡选育和科学养殖提供数据支持。选用北京油鸡纯系公鸡,出雏时,按照主翼羽与覆主翼羽的羽长差值将其分为快慢羽亚群,其中快羽包括K1（主翼羽长于覆主翼羽>5 mm）和K2（主翼羽长于覆主翼羽2~5 mm）,慢羽包括M1（主翼羽与覆主翼羽等长或主翼羽长于覆主翼羽<2 mm）和M2（主翼羽短于覆主翼羽）和M3（主翼羽未长出）。1~7日龄每隔1 d测量1次主翼羽与覆主翼羽羽长,7~42日龄每隔1周测量1次;1~8周龄每周测量体重,9~18周龄每隔1周测定体重;10周龄时,观测公鸡全身羽毛发育情况;47周龄时,测定公鸡常规精液品质性状、精子动力学参数、受精率及孵化率。结果显示,快羽公鸡占北京油鸡公鸡总数的11.60%,慢羽占88.40%,慢羽又以M2型为主,有少量M1型和M3型。育雏育成期（1~18周）北京油鸡快慢羽公鸡各周龄体重均无显著差异（P>0.05）。在育雏育成期,慢羽公鸡主翼羽和覆主翼羽生长均慢于快羽公鸡。其10周龄时,背部和腿部羽毛生长完全的鸡的比例仅为44%,且不同类型的慢羽公鸡的比例也不一,其中等长型或微长型慢羽最高,超过90%,未长出型慢羽最低,仅为17%左右。47周龄时快羽鸡和慢羽鸡的常规精液品质无差异,但是快羽公鸡精子直线性显著高于慢羽鸡（P<0.05）,直线速率高于慢羽公鸡（P=0.06）,快羽北京油鸡公鸡受精率显著高于慢羽公鸡（P<0.05）,且入孵蛋孵化率和受精蛋孵化率有高于慢羽公鸡的趋势,但差异不显著（P>0.05）。本研究结果表明,快慢羽北京油鸡公鸡的羽毛生长和繁殖性能有一定差异,需要加强慢羽公鸡羽毛发育缓慢原因和鉴定方法的研究,也需加强慢羽公鸡精液品质选育。     

Three-dimensional reconstruction of intramuscular collagen networks of bovine muscle: A demonstration by an immunohistochemical/confocal laser-scanning microscopic method

We undertook a three‐dimensional reconstruction of intramuscular collagen networks of bovine muscle using an immunohistochemical/confocal laser‐scanning microscopic method. By immunohistochemical staining, type I and III collagens were observed mainly in the perimysium, while type IV collagen was observed in the endomysium. On the other hand, type V and VI collagens were observed in both the perimysium and endomysium. By confocal laser‐scanning microscopy, the collagen observed in the perimysium was three‐dimensionally reconstructed as plate‐shaped layers whereas the collagen observed in the endomysium surrounded myofibers. The three‐dimensionally reconstructed observations using immunohistochemical/confocal laser‐scanning microscopic method is useful for investigating collagen networks in muscle.     

紫花苜蓿根颈芽越冬期间幼叶细胞超微结构的适应性变化

为了探讨紫花苜蓿根颈芽越冬抗寒的细胞学机理,本研究以WL168为材料,应用透射电镜技术跟踪观察了根颈芽在自然越冬过程中幼叶细胞的超微结构变化。结果显示,1)在越冬期间,苜蓿根颈芽幼叶细胞超微结构发生了一系列积极适应低温的变化,主要表现为:质膜内陷,中央大液泡分割成多个小液泡,染色质凝集,质体变为月牙形或马蹄状,淀粉粒减少甚至消失,质壁分离等,细胞超微结构经过适应性调整,逐渐提高了根颈芽的抗寒能力。2)根颈芽在越冬期间同时存在白芽与褐芽两种发育状态,其中白芽幼叶细胞对越冬前的降温反应迟缓,直到土壤封冻后才完全形成抗寒结构,但是到了翌年早春,细胞超微结构变化快速,很早便解除抗寒状态,恢复生长。在整个越冬过程中白芽的抗寒性表现出4个不同的发育阶段:抗寒性增强期(10月下旬至12月中旬),抗寒性保持期(12月下旬至1月中旬),抗寒性减退期(1月下旬至2月下旬)和抗寒性解除期(3月初至3月中旬)。相反,褐芽幼叶细胞在入冬前对气温下降提前作出了反应,但在翌年早春对气温的回升却反应缓慢,到3月中旬,细胞结构依然保持抗寒特性。越冬期两种根颈芽的存在以及细胞超微结构响应低温的不同步性,是苜蓿越冬抗寒的一种适应策略。     

A gene co‐expression network analysis of the candidate genes and molecular pathways associated with feather follicle traits of chicken skin

Back and thigh skin of chickens showed significant differences in the thickness and the feather follicle density and size, which are important traits for slaughtered chickens' appearance. In the present study, global gene expression profiling was conducted in the back and thigh skin of chickens using Microarray technology. The results showed that 676 genes were differentially expressed between back and thigh skin. The expression of the differentially expressed genes (DEGs), including PPP1R3C, IGF1, PTCHD1, HOXB6, FGF9, CAMK4, SHH, BMP8B, FOXN1 and PTGER2, was validated by real‐time quantitative polymerase chain reaction (RT‐qPCR), and the results were consistent with microarray results. Functional analysis revealed that the DEGs were significantly involved in cell proliferation, differentiation, apoptosis, adhesion and transport process, and the pathways were significantly mapped into the ECM‐receptor interaction, peroxisome, focal adhesion, Hedgehog and PPAR signalling pathways. Protein–protein interaction network analysis suggested that signalling pathways related to feathers morphogenesis and development, such as Wnt, FGF, MAPK, SHH and BMP signalling pathways, occupied important positions in the network. Genes involved in these signalling pathways and adhesion molecules might play a vital role in skin and feather follicle development. Further single nucleotide polymorphism (SNP) association analysis of Wnt3A showed that the AC genotype of SNP g.255361 C>A significantly increased the feather follicle density of thigh skin. Our findings may provide new insights on candidate genes and pathways related to skin and feather follicle formation of chickens.     

昆明地区盆栽苹果诱导二次开花试验研究

盆栽苹果二次开花能够提高观赏价值,延长观赏期,从而能够促进苹果盆景产业的发展。本试验显微观察了苹果花芽的形态分化进程,并通过全株脱叶和喷施单氰胺溶液对昆明地区不同品种的盆栽苹果进行二次开花试验。试验结果表明：‘嘎啦’在8月中旬花芽处于萼片形成期,‘富士’在8月中旬花芽处于花蕾分化期,‘红色之爱’在8月中旬花芽处于花瓣形成期,‘神砂’和‘皮诺娃’在8月中旬花芽处于雄蕊形成期;‘嘎啦’和‘富士’在10月上旬花芽处于雄蕊形成期,‘红色之爱’、‘皮诺娃’和‘神砂’在10月上旬花芽处于雌蕊形成期;在12月上旬5个苹果品种的花芽均进入雌蕊形成期。9月初通过全株脱叶和喷施单氰胺溶液处理,‘嘎啦’、‘富士’、‘神砂’和‘皮诺娃’成功实现了二次开花,‘嘎啦’、‘神砂’和‘皮诺娃’二次开花后成功挂果。     

Distribution of type VI collagen in the cartilaginous tissue of the proximal tibia in the domestic cat

To investigate the distribution of the early stage chondrocytes during the formation and closure of epiphyseal growth plate (EGP) of the domestic cat, we examined the EGP of proximal tibiae by immunohistochemistry for type VI collagen. In the epiphyseal cartilage without the secondary ossification center (SOC) and EGP in newborn cats aged 1 and 10 days, type VI collagen-positive chondrocytes were located around the cartilage canals and articular surface. In the epiphyseal cartilage with the SOC and EGP in young cats aged 1 to 3 months, type VI collagen-positive chondrocytes were located in the upper resting zone of the EGP, and then increased throughout the resting zone along with maturation. In the adult cats with the partially closed EGP, type VI collagen-positive chondrocytes were distributed throughout the remaining EGP. These findings indicate that the early stage chondrocytes characterized with type VI collagen are continuously located in the EGP during maturation. In addition, the increase of the early stage chondrocytes and the decrease of the reserve chondrocytes in the EGP along with maturation may cause the cessation of the longitudinal growth of the EGP, and finally bring about the EGP closure.     

Amounts and Variation of Soluble Collagen in Mink Skin During Growth from Kits to Adult Animals

The soluble collagen from mink skin was extracted from 2-week to 6-month-old animals. A total of 14 different age groups, each containing three animals, was studied by using two different buffers for collagen extraction. The amount of soluble collagen was measured. The various collagen species were characterized using capillary zone electrophoresis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis and protein blotting followed by antibody analysis for type I collagen. The data showed that the amount of soluble collagen declines with age. Using capillary electrophoresis it was also found that the distribution of soluble collagen differs in very young kits' skin compared with older animals' skin, whereas the skin from animals more than 2 weeks old was found to contain the same proportions of various collagen species. Antibody analysis of type I collagen found no difference in the relative amount between different age groups, and only the acetic acid-containing buffer extracted type I collagen from the mink skin.     

Isolation of chicken taste buds for real‐time Ca2+ imaging

We isolated chicken taste buds and used a real‐time Ca²⁺ imaging technique to investigate the functions of the taste cells. With RT‐PCR, we found that isolated chicken taste bud‐like cell subsets express chicken gustducin messenger RNA. Immunocytochemical techniques revealed that the cell subsets were also immunopositive for chicken gustducin. These results provided strong evidence that the isolated cell subsets contain chicken taste buds. The isolated cell subsets were spindle‐shaped and approximately 61–75 μm wide and 88–98 μm long, and these characteristics are similar to those of sectional chicken taste buds. Using Ca²⁺ imaging, we observed the buds' response to 2 mmol/L quinine hydrochloride (a bitter substance) and their response to a mixture of 25 mmol/L L‐glutamic acid monopotassium salt monohydrate and 1 mmol/L inosine 5′‐monophosphate disodium salt, umami substances. The present study is the first morphological demonstration of isolated chicken taste buds, and our results indicate that the isolated taste buds were intact and functional approaches for examining the taste senses of the chicken using Ca²⁺ imaging can be informative.     

Immunohistological distributions of fibronectin, tenascin, type I, III and IV collagens, and laminin during tooth development and degeneration in fetuses of minke whale, Balaenoptera acutorostrata.

The immunohistological distributions of fibronectin, tenascin, type I, III and IV collagens, and laminin were observed in the tooth buds of fetuses of minke whale, Balaenoptera acutorostrata. Distributions of extracellular matrices (ECMs) examined in this study except for tenascin were generally similar to those of terrestrial mammalian species during development of the tooth bud. Tenascin in the fetuses of minke whale showed characteristic distributions in the dental lamina and the enamel organ in the early tooth developmental stage. In the physiological degeneration stage of tooth bud development, immunoreactivity of the ECMs were very weakly and limitedly detected in the dental papilla and the surrounding mesenchyme. Immunoreactivity of tenascin and type I and III collagens were positively detected in the developing baleen plate germ which was associated with the degenerating tooth bud. These findings suggested that expressions of the ECMs were related to the formation of the tooth bud and baleen plate germ, and that the lack of the ECMs was related to the degeneration of the tooth bud in the fetal minke whale.     

封育和放牧对黄土高原典型草原芽库的影响

在多年生草地生态系统中,芽库在干扰后的种群补充和更新中占据着重要地位。本研究采用单位面积挖掘取样法,比较分析了封育和放牧对黄土高原典型草原地上植被特征和芽库密度的影响。结果表明,黄土高原典型草原芽库以分蘖芽为主,密度为832~6 848芽·m~(-2)。与放牧相比,短期封育显著提高了芽库总密度和禾草芽库密度,但显著降低了非禾草芽库密度(P0.05)。封育和放牧对典型草原芽库密度的显著影响,主要来自根茎型、分蘖型和根蘖型牧草芽库的贡献。短期封育显著提高根茎型和分蘖型牧草的芽库密度,而显著降低根蘖型牧草的芽库密度(P0.05)。禾草芽密度与地上生物量呈显著正相关,与地上茎分枝数呈显著负相关(P0.05)。封育和放牧对黄土高原典型草原地上植被特征的影响可能是通过调控禾草芽库密度来实现的。在草地管理中,芽库对地上植被的发展有一定的指示作用,可以依靠芽库的测定来预测未来植被的产量、演替趋势和发展方向。     

Properties of alkaline‐hydrolyzed waterfowl feather keratin

The properties of hydrolyzed feather keratin (HFK) were compared to those of hydrolyzed wool keratin (HWK) with the aim of developing better ways to utilize feather keratin waste. Amino acid analysis showed that HFK contained more hydrophobic amino acids did than HWK. Although gel permeation chromatography indicated that HFK and HWK had more low‐molecular weight peptides than their intact sources, Fourier transform infrared spectroscopy indicated that both hydrolyzed keratins retained their original secondary structure. The physical properties of HFK were evaluated by treating HFK to human hair fibers. HFK treatment enhanced significantly the surface hydrophobicity and strength of fibers, and HFK was more permeable into hair fibers. These results suggest that HFK is suitable for industrial applications to improve fibers. In addition, HFK may be suitable for raw material of products requiring both flexibility and hydrophobicity, such as films and biodegradable plastics.     

乌蒙凤鸡肉用专门化品系选育初探

本研究旨在对不同类型乌蒙凤鸡的生长性能进行测定分析,为乌蒙凤鸡肉用专门化品系的选育奠定基础。实验测定了乌蒙凤鸡不同羽色(黄羽、麻羽)、肤色(乌骨、普通)及不同羽色与肤色的组合(黄羽普通、黄羽乌骨、麻羽普通、麻羽乌骨)4个类型鸡群4～24周龄的生长性能。结果表明:按羽色或肤色的单一性状进行划分,乌蒙凤鸡黄羽和麻羽、普通和乌骨之间生长性能差异不显著;黄羽公鸡4～16周龄生长性能显著高于麻羽公鸡;不同羽色和肤色的公鸡生长性能均高于母鸡(P<0.01);黄羽普通鸡群体生长性能高于其他类型鸡群。根据分析测定结果,建议将黄羽普通鸡作为乌蒙凤鸡肉用专门化品系选育的候选类型。     

Involution in vitro, regeneration and functional activity of the apical ectodermal ridge of the chick limb bud]

In order to detect morphological changes and activity of the apical ectodermal ridge of the chike embryo limb bud, a series of “in vitro” and “in ovo” experiments were planned. “In vitro* bioassay: ectodermal covering from stage 21 limb buds were cultured in limb bud extracts and non limb bud extracts. Tissues after culture were examined under optic and electron microscopies. “In ovo” studies: Ectodermal jakets, previously cultured, were recombinated with intact limb bud mesoderm and then grafted onto a host embryo. Limb bud extract was able to maintain the ectodermal ridge and even to regenerate flattened ridges previously cultured in non limb bud extracts. The regenerated ridge did not loose the capacity to induce the growth of distal segments of the limb. The regenerated ridge was only produced at the level of its primitive region.