Asymmetric expression of CA2 and CA13 linked to calcification in the bilateral mandibular condyles cause crossed beaks in chickens

Crossed beak is a complex mode of inheritance with prevalence ranging from 0.2 to 7.4% in at least 12 chicken strains worldwide.To reveal the intrinsic factors causing crossed beaks,genes expression patterns in bilateral mandibular condyle between affected and normal birds were characterized by RNA sequencing analysis in the present studies.Crossed beak was induced by short length of unilateral mandibular ramus,and a total of 110differentially expressed genes were up-or down-regulated in the affected(short)mandibular condyle side as compared to the normal side.Carbonic anhydrase 2(CA2)and Carbonic anhydrase 13(CA13)were enriched in the carbonate dehydratase activity,and high-expressed in mandibular condyle and osteoblasts(P<0.05).However,both were low-expressed in short mandibular condyle side of affected birds(P<0.05).The carbonate dehydratase inhibitor experiments confirmed that there is positive association between the calcification and carbonic anhydrase isoenzymes.Quantitative analysis with cetylpyridinium chloride showed a decrease in calcification when the cells were transfected with an anti-CA13 shRNA.Our research suggested that CA2 and CA13 are down-calcified in shortside mandibular condyle,and caused mandibular ramus to grow slowly.CA2 and CA13 have the critical role in crossed beaks by regulating calcification of mandibular condyle.

Monochromatic green light stimulation during incubation shortened the hatching time via pineal function in White Leghorn eggs

Background:Effect of monochromatic green light illumination on embryo development has been reported in chickens.The avian pineal gland is an important photo-endocrine organ formed by a mediodorsal protrusion during embryonic development.However,the involvement of pineal gland in the light transduction process remains to be elucidated.In the present study,we investigated the influence of monochromatic green light on hatching time and explored the possible mechanism via pineal function.Results:A total of 600 eggs of White Leghorn(Shaver strain)were incubated under photoperiods of either 12 h of light and 12 h of darkness using monochromatic green light(12L:12D group)or 24 h of darkness(0L:24D group)for 18 d.Compared to 0L:24D group,the green light stimulation shortened the hatching time without extending the hatch window or impairing hatchability.The liver of embryos incubated in the 12L:12D light condition was heavier than those of the 0L:24D group on d 21 post incubation which may be linked to the observed increase in the serum concentration of insulin-like growth factor 1(IGF-1);primary secretion of the liver.Histological structure analysis of pineal gland demonstrated that the light stimulation increased follicle area,wall thickness and lumen area on d 10 and d 12 post incubation.Rhythmic function analysis demonstrated that three clock related genes(brain and muscle ARNT-like-1,BMAL1;circadian locomotor output cycles kaput,CLOCK;and cryptochrome-1,CRY1)and a melatonin rate-limiting enzyme related gene(arylalkylamine N-acetyltransferase,AANAT)were rhythmically expressed in the pineal gland of the 12L:12D group,but not in the 0L:24D group.Simultaneously,the light stimulation also increased the concentration of melatonin(MT),which was linked to hepatocyte proliferation and IGF-1 secretion in previous studies.Conclusions:The 12L:12D monochromatic green light stimulation during incubation shortened hatching time without impairing hatching performance.Pineal gland’s early histological development and maturation of its rhythmic function were accelerated by the light stimulation.It may be the key organ in the photo-endocrine axis that regulates embryo development,and the potential mechanism could be through enhanced secretion of MT in the 12L:12D group which promotes the secretion of IGF-1.

Poultry genetic heritage cryopreservation and reconstruction:advancement and future challenges

Poultry genetics resources,including commercial selected lines,indigenous breeds,and experimental lines,are now being irreversibly lost at an alarming rate due to multiple reasons,which further threats the future livelihood and academic purpose.Collections of germplasm may reduce the risk of catastrophic loss of genetic diversity by guaranteeing that a pool of genetic variability is available to ensure the reintroduction and replenishment of the genetic stocks.The setting up of biobanks for poultry is challenging because the high sensitiveness of spermatozoa to freezing–thawing process,inability to cryopreserve the egg or embryo,coupled with the females being heterogametic sex.The progress in cryobiology and biotechnologies have made possible the extension of the range of germplasm for poultry species available in cryobanks,including semen,primordial germ cells,somatic cells and gonads.In this review,we introduce the state-of-the-art technologies for avian genetic resource conservation and breed reconstruction,and discuss the potential challenges for future study and further extending of these technologies to ongoing and future conservation efforts.

Analysis of the Microstructure and Mechanical Properties during Inertia Friction Welding of the Near-α TA19 Titanium Alloy

The current research of titanium alloy on friction welding process in the field of aero-engines mainly focuses on the linear friction welding.Compared to the linear friction welding,inertial friction welding of titanium alloy still has important application position in the welding of aero-engine rotating assembly.However,up to now,few reports on inertial friction welding of titanium alloy are found.In this paper,the near-alpha TA19 titanium alloy welded joint was successfully obtained by inertial friction welding(IFW)process.The microstructures and mechanical properties were investigated systematically.Results showed that the refined grains within 15‒20μm and weak texture were found in the weld zone due to dynamic recrystallization caused by high temperature and plastic deformation.The weld zone consisted of acicularα′martensite phase,αp phase and metastableβphase.Most lath-shapedαs andβphase in base metal were transformed into acicular martensiteα′phase and metastableβphase in thermo-mechanically affected zone and heat affected zone.As a result,the microhardness of welded joint gradually decreased from the weld zone to the base metal.Tensile specimens in room temperature and high temperature of 480℃ were all fractured in base metal illustrating that the inertia friction welded TA19 titanium alloy joint owned higher tensile strength compared to the base metal.

改良直切口幕上下联合入路切除镰幕型小脑幕脑膜瘤的疗效分析

目的分析改良直切口幕上下联合入路并动态牵拉显微切除镰幕型小脑幕脑膜瘤的治疗效果。方法回顾性分析新疆医科大学第一附属医院神经外科自2013年1月至2020年1月收治的70例在接受初次手术的镰幕脑膜瘤患者的临床资料,其中35例患者采用改良直切口联合入路,35例患者采用单一入路。收集2组患者的一般资料(性别、年龄、肿瘤大小、肿瘤位置),分析2组患者手术相关因素(出血量、手术时间、深静脉损伤、肿瘤切除程度)、住院天数及术后并发症差异。结果2组患者术前一般资料比较差异无统计学意义(P>0.05),具有可比性。术后随访6个月,2组患者的出血量、手术时间、术后并发症发生率、住院天数比较,差异均无统计学意义(P>0.05)。改良直切口联合入路组术后1周、6个月的KPS评分大于单一入路组,差异有统计学意义(P<0.05)。改良直切口联合入路组与单一入路组的深静脉损伤、肿瘤切除率、皮质盲比较,差异均有统计学意义(P<0.05)。结论针对镰幕型小脑幕脑膜瘤,采用改良直切口联合入路手术打开幕上下硬膜后结合显微镜"锥形视野"和"动态牵拉"技术,可有效减少医源性脑损伤,能获得多角度广泛的深部术野,患者术后并发症发生率低,住院时间短,术后康复效果良好。