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Desertification Drives the Shift in egg Size-Number Trade-Off in an Agamid Lizard

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Asian Herpetological Research 2022年第4期13卷 284-291页

作者： Zhigao ZENG Zhensheng LIU Jinyun WEI Xiaolei ZHANG Weiguo DU Key Laboratory of Animal Ecology and Conservation Biology Institute of ZoologyChinese Academy of SciencesBeijing 10101China College of Wildlife Resources Northeast Forestry UniversityHarbin 150040HeilongjiangChina Key Laboratory of Conservation Biology State Forestry AdministrationHarbin 150040HeilongjiangChina

Desertification is a serious ecological problem leading to significant biodiversity loss,but how desertification drives shifts in life history and fitness of animals remains understudied.To clarify whether habitat desertification causes shifts in life history strategies,we compared ecological factors and reproductive traits of Phrynocephalus przewalskii from three different desertification habitats-fixed dune,semi-fixed dune and mobile dune of a semi-arid region of Inner Mongolia,at the eastern edge of Hobq Desert,China.Our results showed a significant shift in the egg size-number trade-off of P.przewalskii in response to desertification,with lizards from the mobile dune habitat producing smaller clutches of larger eggs than lizards from the fixed and semi-fixed dune habitats.This life history shift is likely adaptive and driven by abiotic factors(temperature and precipitation)rather than biotic factors(food availability and lizard population density).Our study demonstrates that habitat desertification drives the shift in egg size-number trade-off in a lizard and highlights the importance of exploring the life history responses of animals to habitat desertification as well as to other traditionally well-studied factors like temperature,especially in the context of future global clima te change.

关键词： desert adaptation egg lifehistory Phrynocephalus przewalskii reptile trade-off

Sexual Dimorphism,Female Reproductive Characteristics and Embryonic Thermosensitivity in the Tonkin Forest Skink(Sphenomorphus tonkinensis)from Hainan,South China

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Asian Herpetological Research 2023年第4期14卷 271-279页

作者： Yu DU Chixian LIN Xiaming ZHU Yuntao YAO Xiang JI Hainan Key Laboratory for Herpetological Research College of Fisheries and Life SciencesHainan Tropical Ocean UniversitySanya 572022HainanChina Zhejiang Provincial Key Laboratory for Water Environment and Marine Biological Resources Protection College of Life and Environmental SciencesWenzhou UniversityWenzhou 325035ZhejiangChina

We collected 75 adult Tonkin forest skinks(Sphenomorphus tonkinensis) from Hainan, South China and incubated eggs at four constant temperatures ranging from 22 ℃ to 28 ℃ to study sexual dimorphism, female reproductive characteristics and embryonic thermosensitivity. The largest male was 53.4 mm snout-vent length(SVL), and the largest female was 54.3 mm SVL. The mean SVL was slightly greater in adult females(49.9 mm) than in adult males(48.8 mm), but the difference was not significant.Head length, head width, fore-limb length and hindlimb length were longer in adult males and abdomen length was longer in adult females after accounting for SVL. Accordingly, we conclude that S. tonkinensis is basically a sexually size-monomorphic species with sexual dimorphism in head size, abdomen(trunk)length and limb size. Females laid up to two clutches of 1–4 eggs each per egg-laying season from February to May. egg mass, clutch size and clutch mass were independent of female SVL. Embryonic stages at laying varied from Dufaure and Hubert’s stage 30 to 31. With female SVL held constant, the negative correlation between egg mass and clutch size was not significant, suggesting that the offspring(egg) sizenumber trade-off between is not evident or eggs are well optimized for size in S. tonkinensis. None of the eggs at 28 ℃ hatched;hatching success was lower at 22 ℃ than at 24 ℃ or 26 ℃. The mean incubation length was 52.9 d at 22 ℃, 40.4 d at 24 ℃ and 33.6 d at 26 ℃. Hatchlings from eggs incubated at 22 ℃,24 ℃ and 26 ℃ did not differ morphologically at hatching, suggesting that temperatures within this range do not differentially affect hatchling morphology in S. tonkinensis.

关键词： egg hatching success hatchling morphology incubation length reproduction Scincidae sexual dimorphism

Xenopus cell-free extracts and their applications in cell biology study

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Biophysics Reports 2023年第4期9卷 195-205页

作者： Junjun Liu Chuanmao Zhang Department of Biological Sciences California State Polytechnic University The Academy for Cell and Life Health Faculty of Life Science and Technology Kunming University of Science and Technology The Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education College of Life SciencesPeking University

Xenopus has proven to be a remarkably versatile model organism in the realm of biological research for numerous years, owing to its straightforward maintenance in laboratory settings and its abundant provision of ample-sized oocytes, eggs, and embryos. The cell cycle of these oocytes, eggs, and early embryos exhibits synchrony, and extracts derived from these cells serve various research purposes. Many fundamental concepts in biochemistry, cell biology, and development have been elucidated through the use of cell-free extracts derived from Xenopus cells. Over the past few decades, a wide array of cell-free extracts has been prepared from oocytes, eggs, and early embryos of different Xenopus species at varying cell cycle stages. Each of these extracts possesses distinct characteristics. This review provides a concise overview of the Xenopus species employed in laboratory research, the diverse types of cell-free extracts available, and their respective properties. Furthermore, this review delves into the extensive investigation of spindle assembly in Xenopus egg extracts, underscoring the versatility and potency of these cell-free systems in the realm of cell biology.

关键词： Xenopus Cell-free extract Oocyte egg Embryo Meiosis Mitosis Spindle

Influence of Tidal Cycles on Embryonic Rotation,Hatching and Emergence of Mangrove Horseshoe Crab,Carcinoscorpius rotundicauda

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Journal of Ocean University of China 2022年第3期21卷 557-563页

作者： KUANG Yang TAN Kian Ann FU Yijian YANG Xin XU Peng ZHEN Wenquan WANG Xueping HUANG Xing ZHU Junhua WANG Chun-Chieh KWAN Kit Yue Guangxi Key Laboratory of Beibu Gulf Marine Biodiversity Conservation College of Marine SciencesBeibu Gulf UniversityQinzhou535011China College of Fisheries Huazhong Agricultural UniversityWuhan430070China Guangxi Beibu Gulf Marine Research Center Guangxi Academy of SciencesNanning530007China

Horseshoe crabs are iconic and ecologically significant macroinvertebrates in coastal environments.The processes and mechanisms of larval hatching in Asian horseshoe crabs that occurs beneath the sand are largely unknown.The spawning and developmental ecology of Tachypleus tridentatus and T.gigas are assumed to be similar to their Atlantic counterpart Limulus polyphemus.However,Carcinoscorpius rotundicauda has been cited as an exception owing to their frequent sightings in muddy mangrove areas even during low tides.To reveal the larval hatching mechanisms,in this study,we examined varying hatching responses of C.rotundicauda embryos within the sediment to the environmental conditions under continuous tidal cycles.During the eight-week experiment,the count of hatched larvae ranged 4%–30%per week,while the cumulative emergence rate from the sediment was 0–47%.Embryos were observed to have the highest active rotation activity in the first two weeks after incubation.The inundation of tidal water significantly enhanced the occurrence of hatching,in which hydration,osmotic shock and possibly agitation had triggered or facilitated the eclosion.The larvae were found to remain in the sediment for approximately 2–6 weeks before emergence.In general,C.rotundicauda was found to share a similar hatching mechanism with L.polyphemus.Our findings provide insight into the developmental ecology of Asian horseshoe crabs exposed to varying tidal conditions,and are helpful to the management and protection of their spawning habitats.

关键词： environmental cue hydration osmotic pressure tidal inundation egg trilobite larva

Monitoring dioxins and PCBs in eggs as sensitive indicators for environmental pollution and global contaminated sites and recommendations for reducing and controlling releases and exposure

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Emerging Contaminants 2022年第1期8卷 254-279页

作者： Jindrich Petrlik Lee Bell Joe DiGangi Serge Molly Allo'o Allo'o Gilbert Kuepouo Griffins Ochieng Ochola Valeriya Grechko Nikola Jelinek Jitka Strakova Martin Skalsky Yuyun Ismawati Drwiega Jonathan N.Hogarh Eric Akortia Sam Adu-Kumi Akarapon Teebthaisong Maria Carcamo Bjorn Beeler Peter Behnisch Claudia Baitinger Christine Herold Roland Weber International Pollutants Elimination Network(IPEN) GooteborgSweden Arnika e Toxics and Waste Programme Delnicka 13PragueCzech Republic National Toxics Network(NTN) PerthAustralia National SAICM Focal Point President of the Tenth Conference of the Parties to the Rotterdam ConventionMinistry of ForestryFisheries and EnvironmentLibrevilleGabon Centre de Recherche et d‘Education pour le Developpement(CREPD) YaoundeCameroon Centre for Environmental Justice and Development(CEJAD) NairobiKenya University of Chemistry and Technology Technicka 5PragueCzech Republic Arnika e Citizens'Support Center Delnicka 13PragueCzech Republic Nexus3 Foundation Denpasar80223Indonesia Department of Environmental Science Kwame Nkrumah University of Science and TechnologyKumasiGhana Ghana Atomic Energy Commission National Nuclear Research InstituteAccraRepublic of Ghana Chemicals Control and Management Centre Environmental Protection AgencyAccraGhana Ecological Alert and Recovery e Thailand(EARTH) NonthaburiThailand La Red de Accion en Plaguicidas y sus Alternativas para America Latina MontevideoUruguay BioDetection Systems BV(BDS) Science Park 4061098 XHAmsterdamthe Netherlands Bund für Umwelt und Naturschutz(BUND) Germany POPs Environmental Consulting D-73527Schw€abisch GmündGermany

This review compiles information on PCDD/F-and PCB-contaminated eggs from 20 years of global egg monitoring around emission sources in four continents conducted by the International Pollutants Elimination Network(IPEN)and Arnika as well as a compilation of data from scientific literature.IPEN monitored 127 pooled egg samples including samples from 113 chicken flocks at potential PCDD/F-and PCB-contaminated sites around priority sources listed in the Stockholm Convention(e.***.waste incinerators,metal industries,cement plants,and open burning).99(88%)of pooled egg samples were above the EU maximum limits for PCDD/Fs(2.5 pg PCDD/F-TEQ/g fat)or the sum of PCDD/Fs and dioxinlike PCBs(5 pg PCDD/F-PCB-TEQ/g fat).Children consuming such eggs exceed the tolerable weekly intake(TWI).This demonstrates that close to 90%of these areas were not safe for the production of free-range eggs.Sixteen out of the 113 egg samples(14%)were contaminated above 50 pg TEQ/g fat and exceeded the EU maximum limit more than 10 times.From the 26 pooled egg samples around incinerators 24(92%)exceeded the limit with a mean of 43.1 pg TEQ/g fat(2.6e234 pg TEQ/g).All 21 egg samples around metal industries(4.4e112.6 pg TEQ/g fat)were above limits with mean concentration of 26.0 pg TEQ/g fat.Also all 7 egg samples measured at e-waste recycling sites were above limits(mean 308 pg TEQ/g fat).In 58(51%)pooled egg samples the PCB-TEQ was above 5 pg TEQ/g fat exceeding the EU maximum limit with dioxin-like PCBs alone.This highlights the role of commercial PCBs for global contamination with dioxin-like compounds.It was discovered that around metal industries,shredder plants,open burning sites of e-waste and dump sites,a high share of contamination was caused by dl-PCBs.This clearly shows severe PCB release from the end-of-life management of PCB-containing equipment in developing countries.Also highly contaminated eggs were found at many sites where plastic was incinerated.The highest contaminated egg sample ever measured came from an e-waste site in Ghana a

关键词： PCDD/PCDF dl-PCBs PBDD/PBDF Contaminated sites Monitoring egg DR CALUX

Polybrominated diphenyl ethers in chicken tissues and eggs from an electronic waste recycling area in southeast China

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Journal of Environmental Sciences 2011年第1期23卷 133-138页

作者： Xiaofei Qin Zhanfen Qin Yan Li Yaxian Zhao Xijuan Xia Shishuai Yan Mi Tian Xingru Zhao Xiaobai Xu Yongjian Yang State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-environmental Sciences Chinese Academy of Sciences Beijing 100085 China Chinese Research Academy of Environmental Sciences Beijing 100012 China Taizhou No. 1 Middle School Taizhou 318000 China

The levels and distributions of polybrominated diphenyl ethers （PBDEs） in chicken tissues from an electronic waste （e-waste） recycling area in southeast China were investigated. Human dietary intake by local residents via chicken muscle and eggs was estimated. The mean PBDEs concentrations in tissues ranged from 15.2 to 3138.1 ng/g lipid weight （lw） and in egg the concentration was 563.5 ng/g lw. The results showed that the level of total PBDEs （∑PBDEs） in the chicken tissue was 2-3 orders of magnitude higher than those reported in the literature. The large difference of ∑PBDEs concentrations between tissues confirmed that the distribution of PBDEs in tissues depend on tissue-specificity rather than the ＂lipid-compartment＂. BDE-209 was the predominant congener （82.5%- 94.7% of ∑PBDEs） in all chicken tissues except in brain （34.7% of ∑PBDEs）, which indicated that deca-BDE （the major commercial PBDE formulation comprising 65%-70% of total production） was major pollution source in this area and could be bioaccumulated in terrestrial animals. The dietary PBDEs intake of the local residents from chicken muscle and egg, assuming only local bred chickens and eggs were consumed, ranged from 2.2 to 22.5 ng/（day.kg body weight （bw）） with a mean value of 13.5 ng/（day-kg bw）, which was one order of magnitude higher than the value reported in previous studies for consumption of all foodstuffs.

关键词： polybrominated diphenyl ethers chicken egg bioaccumulation tissue distribution exposure risk

Effect of dietary inclusion of sugar syrup on production performance,egg quality and blood biochemical parameters in laying hens

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Animal Nutrition 2018年第1期4卷 59-64页

作者： Ahmed S.Hussein Mostafa A.Ayoub Ahmed Y.Elhwetiy Jamal A.Ghurair Mohsin Sulaiman Hosam M.Habib College of Food and Agriculture United Arab Emirates University Al-Khaleej Sugar CO (L.L.C.)

The effects of dietary inclusion of sugar syrup on quality of egg,cholesterol level,production performance,serum total protein and blood biochemical parameters were evaluated in laying hens.A total of300 commercial Lohmann LSL hens(30 weeks of age) were randomly distributed into 3 dietary treatments which consisted of a normal corn diet containing cornesoy and 2 diets containing 5% and 10%sugar syrup.Each treatment was replicated 5 times(n=20).egg production,feed intake,body weight and egg weight of laying hens fed different diets were recorded.The experiment lasted for 20 weeks.The Haugh unit scores of hens fed diets with sugar syrup were significantly increased(P eggs laid by hens fed sugar syrup diets had lower cholesterol level(P eggs and blood biochemical parameters in layer hens,which suggests sugar syrup can be used as an energy source for replacing part of corn in poultry layer diets.

关键词： Cholesterol Sugar syrup diet egg egg quality Protein

Effects of dietary phosphorous supplementation on laying performance,egg quality,bone health and immune responses of laying hens challenged with Escherichia coli lipopolysaccharide

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Journal of Animal Science and Biotechnology 2018年第4期9卷 980-990页

作者： Wei Nie Bo Wang Jing Gao Yuming Guo Zhong Wang State Key Laboratory of Animal Nutrition College of Animal Science and Technology China Agricultural University Department of Animal Science Washington State University

Background: Phosphorus is an essential nutrient to maintain poultry health and performance. The objective of this study was to evaluate the effect of dietary phosphorus levels on egg production, egg quality, bone health, immune responses of laying hens challenged with Escherichia coli lipopolysaccharide.Methods: Three hundred laying hens at 28 wk were randomly divided into 2 dietary treatments with 10 replicates of 15 birds. The wheat-soybean based diets contained either 0.12% or 0.4% non-phytate phosphorus(NPP). At 32 wk of age, all the birds of each dietary treatment were injected into the abdomen with 1.5 mg/kg body weight(BW) of either LPS or saline once a day at 24-h intervals for continuous 9 d. The performance of laying hens was evaluated for 9 d. The eggs after the fifth injection were collected to value the egg quality. Three hours after the first injection, blood was collected to measure serum metabolite and immune response associated parameters.Three hours after the fifth injection, the hens were euthanized to obtain tibia, cecal tonsils and jejunum.Results: Compared with saline-injected hens, LPS-injected hens had lower feed intake and egg production(P eggshell thickness, strength, albumin height and Haugh unit were significantly increased in LPS-injected hens compared with saline-injected hens(P < 0.05). Furthermore, laying hens challenged with LPS had lower villious height/crypt depth ration than those received saline. Serum calcium, phosphorus and SOD activities significantly decreased in the LPS-injected hens compared with the control(P < 0.05). LPS up-regulated expression of IL-1β, IL-6 and IL-10 in cecum, and serum concentration of MDA, IL-1β and IL-6(P < 0.05), whereas 0.40% dietary non-phytate phosphorus supplementation significantly increased(P < 0.05) villi height/crypt depth ratio, decreased(P < 0.05) serum MDA and IFN-γ concentration compared with the 0.12% non-phytate phosphorus group.Conclusion: In summary, this study demonstrates that 0.40% dietary non-phytate phosphorus supplem

关键词： egg quality Immune response Laying hens Lipopolysaccharide Phosphorus

Effect of supplementing layer hen diet with phytogenic feed additives on laying performance, egg quality, egg lipid peroxidation and blood biochemical constituents

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Animal Nutrition 2018年第4期4卷 394-400页

作者： Reham Abou-Elkhair Shaimaa Selim Eman Hussein Department of Nutrition and Clinical Nutrition Faculty of Veterinary Medicine University of Sadat City Department of Nutrition and Clinical Nutrition Faculty of Veterinary Medicine University of Menoufia Department of Poultry Production Faculty of Agriculture University of Menoufia

This study was conducted to evaluate the effects of supplementing laying hen diet with phytogenic additives on laying performance, egg quality, blood constituents and egg lipid peroxidation. Two hundred Lohmann Brown Lite laying hens were randomly allotted to 4 dietary treatments: control(without phytogenic additive), fennel seeds(5 g/kg), black cumin seeds(5 g/kg) and hot red pepper(5 g/kg).Each of the 4 diets was fed to 5 replicates of 10 hens for 8 weeks. No significant differences were observed in body weight or feed intake between the groups. Dietary inclusion of fennel followed by red pepper improved(P egg weight, egg production, egg mass and feed conversion ratio compared with control. Higher yolk shape index, shell and albumen weight percentages and Haugh unit(P egg yolk color score increased by the addition of fennel or hot red pepper in laying hen diets compared with control. The inclusion of black cumin or hot red pepper decreased serum and egg yolk cholesterol and malondialdehyde concentrations(P egg quality were obtained by dietary inclusion of fennel, followed by hot red pepper and black cumin. Dietary supplementation of black cumin or red pepper may lead to the development of low-cholesterol concentration and better antioxidant capacity of eggs.

关键词： Phytogenic additives egg quality Hepatoprotective activity Lipid peroxidation Cholesterol Laying hens