Planar cell polarity: intracellular asymmetry and supracellular gradients of Dachsous

The slope of a supracellular molecular gradient has long been thought to orient and coordinate planar cell polarity (PCP). Here we demonstrate and measure that gradient. Dachsous (Ds) is a conserved and elemental molecule of PCP; Ds forms intercellular bridges with another cadherin molecule, Fat (Ft), an interaction modulated by the Golgi protein Four-jointed (Fj). Using genetic mosaics and tagged Ds, we measure Ds in vivo in membranes of individual cells over a whole metamere of the Drosophila abdomen. We find as follows. (i) A supracellular gradient rises from head to tail in the anterior compartment (A) and then falls in the posterior compartment (P). (ii) There is more Ds in the front than the rear membranes of all cells in the A compartment, except that compartment''s most anterior and most posterior cells. There is more Ds in the rear than in the front membranes of all cells of the P compartment. (iii) The loss of Fj removes intracellular asymmetry anteriorly in the segment and reduces it elsewhere. Additional experiments show that Fj makes PCP more robust. Using Dachs (D) as a molecular indicator of polarity, we confirm that opposing gradients of PCP meet slightly out of register with compartment boundaries.     

胸三角皮瓣并自体脂肪移植修复颌面部大面积缺损畸形

目的：探讨颌面部皮肤软组织大面积缺损凹陷的理想修复方法。方法：本组6例均为爆炸伤后颌面部皮肤软组织缺损及严重凹陷畸形,采用胸三角皮肤扩张形成带蒂皮瓣修复上述皮肤缺损及自体脂肪移植纠正残存凹陷畸形。手术分五步进行：1．胸三角深筋膜浅层埋植500mL-800mL皮肤扩张器并注水扩张3个月。2井艮据面颈部预计皮肤缺损大小及形状作皮瓣预制并面部局部皮瓣纠正器官移位。3．带蒂皮瓣转移修复颌面部缺损。4．蒂部延迟及断蒂微整形。5．自体脂肪移植。结果：所有皮瓣成活良好,皮瓣色质接近面颈部周围正常皮肤,缺损畸形修复,外观形态好,供区直接缝合无需植皮,取得了较好的面部改观效果。结论：对于面部大面积皮肤软组织缺损,合并面部凹陷、面部器官缺损及移位,采取胸三角扩张延迟预制皮瓣并自体脂肪移植修复可取得良好的整复效果,为颌面部战创伤畸形提供了理想的修复方法。     

鸡Leptin基因正确性的免疫验证

①取20只240日龄的粤黄鸡种母鸡平分为处理组和对照组,分别在第3、31、63和84d对之接种鸡Leptin重组融合蛋白(处理组)或BSA(对照组)1mL/羽。每天记录产蛋率,每10天测定采食量,每两周称重,在试验的第1、31、53、78和91d采血。结果表明Leptin处理组的血浆抗Leptin抗体水平和Leptin水平在免疫后显著高于对照组(P<0.01);第3和4次免疫后处理组产蛋率比对照组显著低约50%(P<0.05);在第98d试验结束时,处理组腹脂量为(115.60±15.07)g,显著高于对照组[(77.98±5.70)g,P<0.05];试验期间处理组的采食量略低于对照组,增重则略高于对照组,但两者差异均不显著(P>0.05);处理组血浆总T3和总T4水平与对照组差异不显著(P>0.05)。②取12只50日龄的粤黄鸡后备小母鸡,平分成处理组和对照组,分别肌注含抗Leptin抗体的卵黄提取液和生理盐水6mL/只,处理组在2、4、6h的累积采食量显著高于对照组(P<0.05),但在8h的累积采食量与对照组差异不显著(P>0.05)。两个试验通过免疫重组鸡Lep tin融合蛋白,使鸡表现出Leptin功能的丧失,证明目前所克隆的鸡Leptin基因在家鸡中的确存在和其正确性。     

Linkage exclusion analysis of two candidate regions on chromosomes 7 and 11: leptin and UCP2/UCP3 are not QTLs for obesity in US Caucasians

Leptin (LEP) and the uncoupling proteins 2 and 3 (UCP2/UCP3) are key molecules involved in the regulation of food intake and energy expenditure. However, their contribution to variation of obesity phenotypes in the general population remains controversial. The present study is to investigate whether chromosomal regions 7q and 11q, which contain LEP and UCP2/UCP3, respectively, can be excluded for linkage with obesity phenotypes. The obesity phenotypes include body mass index (BMI), fat mass, and percentage fat mass (PFM), with the latter two measured by dual-energy X-ray absorptiometry. We conducted exclusion linkage analyses using a variance component approach in a sample of 1816 individuals coming from 79 extended Caucasian pedigrees. In this study, we were able to exclude chromosomal region 7q containing LEP as having an effect on fat mass and PFM at effect sizes of 5% or greater, and on BMI at effect sizes of 10% or greater. We were able to exclude chromosomal region 11q containing UCP2/UCP3 as having an effect on fat mass and PFM at effect sizes of 10% or greater, and on BMI at effect sizes of 5% or greater. Our results suggest that the LEP and UCP2/UCP3 genes are unlikely to have a substantial effect on variation in obesity phenotypes in this particular US Caucasian population.     

Larval fat body cells die during the early pupal stage in the frame of metamorphosis remodelation in Bombyx mori

In holometabolus insects, morphology of the larval fat body is remodeled during metamorphosis. In higher Diptera, remodeling of the fat body is achieved by cell death of larval fat body cells and differentiation of the adult fat body from primordial cells. However, little is known about remodeling of the fat body at pupal metamorphosis in Lepidoptera. In this study, we found that cell death of the larval fat body in Bombyx mori occurs at shortly after pupation. About 30% of the fat body cells underwent cell death on days 1 and 2 after pupation. The cell death involved genomic DNA fragmentation, a characteristic of apoptosis. Surgical manipulation and in vitro culture of fat body cells revealed that 20-hydroxyecdysone and juvenile hormone had no effect on either initiation or progression of cell death. During cell death, a large increase in activity of caspase-3, a key enzyme of cell death, was observed. Western blot analysis of the active form of caspase-3-like protein revealed that the length of caspase-3 of B. mori was much larger than that of caspase-3 in other species. The results suggest that larval fat body cells of B. mori are removed through cell death, which is mediated by a caspase probably categorized in a novel family.     

The effect of ecdysone on the fat body cells of the penultimate larvae of Mamestra brassicae

Summary The capability of -ecdysterone to induce autophagocytosis in the fat body cells of penultimate larvae of Mamestra brassicae was investigated both in vivo and in vitro. The hormone proved ineffective when applied for 3 h on the first 3 days of the instar, but it induced the formation of autophagic vacuoles on the 4th day (24 h before ecdysis). This effect became more pronounced when the hormone was administered 10 h before ecdysis. Cells incubated in vitro reacted to ecdysterone more sensitively than cells of similar age treated in vivo. It was concluded that the responsiveness of the fat body cells to ecdysterone as evaluated on the basis of autophagy depends on the age of the larvae. The increased sensitivity of the cells to ecdysterone at the end of the penultimate stage may be related to the decrease of juvenile hormone titre during this period.     

Ascaris suum: Nutrient absorption,growth, and intestinal pathology in young pigs experimentally infected with 15-day-old larvae

Three-week-old pigs on high (HP) or low (LP) protein diets were infected with 15-day-old Ascaris suum larvae (W). Including noninfected pigs (C), the experimental groups were HPW, LPW, HPC, and LPC. After 8 weeks, worm burden in the intestine averaged 42 in LPW and 31 in HPW. Nitrogen balance during Week 4 showed nonsignificantly less nitrogen absorption and retention in LPW compared to LPC. A similar, nonsignificant decrease in fat absorption was recorded in LPW vs LPC and in HPW vs HPC. The weight of the small intestine was significantly greater in W than C pigs but did not differ because of protein level. The weight correlated positively to worm burden and the increase was due mainly to hypertrophy of the tunica muscularis (muscle layers).     

Linalool odor stimulation improves heat stress tolerance and decreases fat accumulation in nematodes

Aromatherapy uses plant essential oils and fragrant ingredients for relaxation, sleep assistance, and improvement of restlessness related to dementia. Certain aromatic substances increase the life span and stress tolerance of nematodes. We investigated effects of exposure to linalool, a linear chain monoterpenic alcohol that is present in the essential oils of many plants, and its optical isomer, l-linalool, in Caenorhabditis elegans. Nematodes were repelled by the odor of both linalool and l-linalool; however, linalool odor stimulation decreased fat accumulation and increased motility after thermal stress. Analysis of a gene-deficient mutant revealed that the DAF-16 insulin-signaling pathway, which is involved in heat stress tolerance, was enhanced by linalool treatment. Linalool stimulation increased the expression of downstream genes such as sod-3 and hsp-12.6 via DAF-16. We conclude that linalool odor induces a repelling behavior in nematodes, improves heat stress tolerance through the DAF-16 signaling pathway, and affects fat accumulation.     

Proteomic changes in the hypothalamus and retroperitoneal fat from male F344 rats subjected to repeated light–dark shifts

Chronic circadian desynchronization induced by repeated 12 h light–dark cycle shifts conducted twice weekly resulted in elevated food intake, body weight gain, and retroperitoneal fat mass in male F344 rats. Using a proteomic approach, we found that repeated light–dark shifts caused changes in expression levels of five hypothalamic (four upregulated) and 22 retroperitoneal fat (13 upregulated) 2‐DE protein spots. Proteins involved in carbohydrate metabolism and in the citric acid cycle were upregulated, indicating a positive energy balance status. In addition, the hypothalamic gamma‐amino butyric acid (GABA) aminotransferase was upregulated, thus suggesting a connection between the brain GABAeric system and the modulation of food intake. Furthermore, the upregulation of fatty acid‐binding protein 4 and the downregulation of 78 kDa glucose‐regulated protein in the fat implicated the development of insulin resistance. We observed the upregulation of two antioxidant enzymes that might serve as protection against insulin dysfunction associated with oxidative stress. Finally, the downregulation of hypothalamic voltage‐dependent anion‐selective channel protein 1 and fat ATP synthase suggested a reduction in synthesis of mitochondrial ATP. These findings are in partial agreement with those of studies of obesity induced by genotype and a high‐fat diet.