皖西白鹅羽区皮肤组织结构的研究及其绒被分析

本试验针对皖西白鹅绒皮制裘生产中的问题，观察研究了１２０、１５０、２００、２４０、３６０、５４０六个日龄组计４８只皖西白鹅绒皮的组织结构。结果表明，各日龄组皮肤结构差异不甚明显。其真皮内羽肌发达，羽囊粗大，脂肪组织含量多，纤维层薄，纤维成分少，排列疏松。２４０日龄以后纤维层增厚。     

The Complete Nucleotide Sequence of a Japanese Isolate of White clover mosaic virus Strain RC

The complete nucleotide sequence was determined for genomic RNA of White clover mosaic virus (WClMV-RC) isolated from red clover (Trifolium pratense) in Japan, It is 5843 nucleotides in length, excluding the poly(A) tail at the 3' terminus. Similar to other potexviruses, it contains five open reading frames (ORFs 1 through 5), which putatively encode an RNA-dependent RNA polymerase (RdRp) (147 kDa), a triple gene block (TGB) (26 kDa/13 kDa/7 kDa), and a coat protein (CP) (22 kDa), respectively. The deduced amino acid sequence of the WClMV-RC CP was identical to that of WClMV-O, one of two New Zealand isolates, but only 85% identical to that of WClMV-M, the other New Zealand isolate, because of heterogeneity in the C-termini of CP amino acid sequences. The implication of this CP heterogeneity is discussed. Received 30 August 2001/ Accepted in revised form 11 January 2002     

Ecotonal changes and altered tree spatial patterns in lower mixed-conifer forests, Grand Canyon National Park, Arizona, U.S.A.

This research analyzes patch development and determines tree spatial patterns along the lower mixed-conifer ecotone on the North Rim of Grand Canyon National Park in Arizona (U.S.A.). Patterns of patch development were interpreted from spatial analyses, based on tree age and size, and past records of disturbance and climate. Five plots in the ecotone between mixed conifer forests and monospecific stands of ponderosa pine (Pinus ponderosa) were studied for patterns of patch development. The methods used include: (1) size-structure analyses, to compare species patch development; (2) dendrochronological dating of tree establishment; (3) tree ring master chronology, to determine periods of suppressed growth, compared to a Palmer Drought Severity Index; and (4) spatial analyses by species composition, size and age, with univariate and bivariate analyses of spatial association and spatial autocorrelation. We found an increased density of shade-tolerant and fire-intolerant species namely clusters of pole-sized white fir, and fewer large ponderosa pine. This revised version was published online in May 2005 with corrections to the Cover Date. This revised version was published online in July 2006 with corrections to the Cover Date.     

兰州“白兰瓜”引种史略探

“白兰瓜”属于厚皮甜瓜的光皮品种类型,出产于“瓜果之城”甘肃兰州,为兰州名优农产品的佼佼者,在国际瓜果市场上曾享有盛誉.基于对相关史料和文献的初步梳理,以亨利·阿加德·华菜士(HenryAgard Wallace)、张心一、华尔特尔·克莱·罗德明(Walter Clay Lowdermilk)等3位中美知名人士的相互关...     

二花脸猪和大白猪背最长肌中肌肉生长抑制素和生肌调节因子基因的表达及其性别特点

用相对定量RT—PCR方法研究大白猪和二花脸猪背最长肌中肌肉生长抑制素（Myostatin）和生肌调节因子（Myo—genin）基因表达的发育性变化并进行品种及性别间比较。研究结果表明：大白猪公猪Myostatin mRNA表达水平在20日龄时达到高峰且显著高于相同日龄二花脸公猪（P〈0．05）,而二花脸公猪在45日龄时才显著升高,其他日龄品种间差异不显著。二花脸公猪和母猪出生后Myostatin mRNA表达水平均表现为上升,45日龄时达到高峰,120日龄时公母猪间差异显著（P〈0．05）。二花脸公猪与大白猪公猪Myogenin mRNA的表达发育模式基本相同,均在20日龄达到最高值,品种问差异不显著。90日龄二花脸母猪Myogenin mRNA表达水平较公猪显著下调（P〈0．05）。结果提示,猪背最长肌中Myostatin和Myogenin基因表达水平在猪出生后早期均较高,但没有出现随着日龄的增加而一直升高或降低的趋势;两种基因的表达在20日龄出现品种间差异;性成熟前后二花脸公母猪间表达有差异。     

Role of type II innate lymphoid cells in browning of white adipose tissue

Type II innate lymphoid cells (ILC2s) are widely distributed in the blood, intestines, trachea, lung, spleen, liver, animal fat and skin, and involved in the innate immune responses. ILC2s have attracted much attention for its important roles in the conversion of white adipose to beige adipose. Studies have shown that ILC2s are essential for the proliferation and differentiation of adipocyte precursor cells, and they also play a vital role in anti-parasitic infection and allergic inflammation. This review discusses the discovery, differentiation, development, distribution and function of ILC2s, and their relationships with the browning of white adipose tissue for providing valuable references on understanding the pathogenesis, prevention and treatment of obesity and fat metabolism disorders.     

Analysis on Target Genes with Mutation in microRNA of Blue-shelled Chicken and White Leghorn

The study was conducted to explore the potential different characters between Blue-shelled chicken and White leghorn.Global genome microRNA was combined the identified microRNA with complementary lab-predicted microRNA.Then the two breed chicken's SNP data got by GGRS were mapped to the microRNA and focused on SNP that deliberately located in mature-microRNA.Bioinformatics method was adopted for target prediction on microRNA which had SNPs.By further gene enrichment analysis,the study found these genes enriched in 22 GO terms,10 KEGG pathways,and 3 IPA important networks.And they enriched in traits which associated with growth,such as mTOR signaling pathways,Wnt signaling pathways,growth hormone receptor networks and insulin-like growth factor Ⅰ receptor networks.And they also enriched in some laying traits,such as oocyte meiotic signaling pathways and progesterone mature oocytes signaling pathways.The methods and the results might provide references for further studies.     

Cutaneous leiomyosarcoma with visceral metastases in a White Carneau pigeon and literature review

Cutaneous leiomyosarcomas are malignant mesenchymal tumors of smooth muscle origin and are reported occasionally in avian species. A 14-y-old male laboratory White Carneau pigeon (Columba livia) was presented for surgical excision of a cervical soft tissue mass. Ultrasonography with color flow Doppler imaging revealed multiple cavitations of mixed echogenicity within the mass and vascularization. Histologically, the dermis and subcutis were expanded by a densely cellular multinodular mass comprised of fusiform cells forming haphazardly arranged broad streams and short interwoven bundles, often surrounding blood vessels and variably sized cavitations. Neoplastic cells were strongly immunopositive for desmin and α–smooth muscle actin, and negative for pancytokeratin, S100, and von Willebrand factor. Based on histopathology and IHC findings, the cutaneous mass was diagnosed as leiomyosarcoma (LMS). The pigeon died 312 d post-operatively. Postmortem examination revealed masses infiltrating the left and right pulmonary airways and one hepatic nodule, but no regrowth at the surgical site. Histologic and IHC evaluation of the pulmonary and hepatic masses were consistent with LMS, representing metastatic foci from the primary cutaneous LMS. Our case highlights the malignant behavior and histomorphologic features of cutaneous LMS in an avian species.     

Genetic analysis for sow stayability at different parities in purebred Landrace and Large White pigs

Genetic parameters for sow stayability were estimated from farrowing records of 10,295 Landrace sows and 8192 Large White sows. The record for sow stayability from parity k to parity k + 1 (k = 1, …, 6) was 0 when a sow had a farrowing record at parity k but not at parity k + 1, and 1 when a sow had both records. Heritability was estimated by using single-trait linear and threshold animal models. Genetic correlations among parities were estimated by using two-trait linear–linear and single-trait random regression linear animal models. Genetic correlations with litter traits at birth were estimated by using a two-trait linear–linear animal model. Heritability estimates by linear model analysis were low (0.065–0.119 in Landrace & 0.061–0.157 in Large White); those by threshold model analysis were higher (0.136–0.200 & 0.110–0.283). Genetic correlations among parities differed between breeds and models. Genetic correlation between sow stayability and number born alive was positive in many cases, implying that selection for number born alive does not reduce sow stayability. The results seem to be affected by decisions on culling made by farmers.     

胺鲜酯(DA-6)浸种对盐胁迫下白三叶种子萌发及抗盐性的影响

以白三叶(Trifolium repens L.‘Haifa’)为研究对象,研究了0.8 mmol·L^-1胺鲜酯(DA-6)浸种处理对白三叶种子在盐胁迫条件下萌发的影响,并对DA-6诱导的耐盐机理进行初步研究,为白三叶的栽培管理提供参考。结果表明,DA-6浸种显著提高了盐胁迫下种子的发芽势、发芽率、活力指数、发芽指数、茎长和鲜干重(P<0.05)。盐胁迫显著诱导了游离脯氨酸和可溶性糖的积累,降低了细胞渗透势(P<0.05)。此外,盐胁迫导致了萌发种子中活性氧(超氧阴离子和过氧化氢)和膜脂过氧化产物丙二醛含量显著增加,电导率显著升高(P<0.05)。DA-6浸种前处理显著提高了胁迫下抗氧化酶(SOD、POD和APX)的活性,增幅分别为33.0%、31.9%和49.1%,这有效地缓解了由盐胁迫引起的氧化损伤,有利于幼苗稳定细胞膜(P<0.05)。本研究表明DA-6浸种处理通过增强抗氧化防御并降低细胞氧化伤害,从而提高盐胁迫下白三叶种子的萌发特性和胁迫耐受性。