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1.
Natalya Y. ERMAKOV Jacob S. ISHAY 《动物学报》2005,51(6):1146-1150
将东方大黄蜂(胡蜂)蛹或幼蜂的棕色表皮层连同含有黑色素的皮细胞层、黄色表皮层及相连的产生黄嘌呤的皮细胞层割下,换化后植入原来的黄蜂体上(原来是黄色的部分用棕色替代,棕色的用黄色替代)。然后将蛹放回原来的子脾中,幼蜂放入一特殊的培养皿中,让其复原和发育。共对200个不同时期的蛹和50只幼蜂进行了试验。结果显示,存活的最主要是将羽化的蛹(差1—2天就羽化的蛹),早期的蛹和幼蜂均死亡。总共有约5%的蛹存活,幼蛹无一存活。在存活的蛹中,棕色表皮植入黄色区域中的不但成活了,而且还保留了棕色色彩。相反,黄色表皮在植入到棕色区域的几天后,就丢失了黄色及膜片。经过表皮异源移植的大黄蜂寿命极短,一般仅几星期。羽化后较敏感,攻击性强,但行走、飞行都很正常[动物学报51(6):1146—1150,2005]。 相似文献
2.
Brenna A. Levine Marlis R. Douglas Amy A. Yackel Adams Bjrn Lardner Robert N. Reed Julie A. Savidge Michael E. Douglas 《Ecology and evolution》2019,9(20):11863-11877
The persistence of an invasive species is influenced by its reproductive ecology, and a successful control program must operate on this premise. However, the reproductive ecology of invasive species may be enigmatic due to factors that also limit their management, such as cryptic coloration and behavior. We explored the mating and reproductive ecology of the invasive Brown Treesnake (BTS: Boiga irregularis) by reconstructing a multigenerational genomic pedigree based on 654 single nucleotide polymorphisms for a geographically closed population established in 2004 on Guam (N = 426). The pedigree allowed annual estimates of individual mating and reproductive success to be inferred for snakes in the study population over a 14‐year period. We then employed generalized linear mixed models to gauge how well phenotypic and genomic data could predict sex‐specific annual mating and reproductive success. Average snout–vent length (SVL), average body condition index (BCI), and trappability were significantly related to annual mating success for males, with average SVL also related to annual mating success for females. Male and female annual reproductive success was positively affected by SVL, BCI, and trappability. Surprisingly, the degree to which individuals were inbred had no effect on annual mating or reproductive success. When juxtaposed with current control methods, these results indicate that baited traps, a common interdiction tool, may target fecund BTS in some regards but not others. Our study emphasizes the importance of reproductive ecology as a focus for improving BTS control and promotes genomic pedigree reconstruction for such an endeavor in this invasive species and others. 相似文献
3.
《Fungal Ecology》2015
Dead wood is an important habitat for forest organisms, and wood decay fungi are the principal agents determining the dead wood properties that influence the communities of organisms inhabiting dead wood. In this study, we investigated the effects of wood decomposer fungi on the communities of myxomycetes and bryophytes inhabiting decayed logs. On 196 pine logs, 72 species of fungi, 34 species and seven varieties of myxomycetes, and 16 species of bryophytes were identified. Although white rot was the dominant decay type in sapwood and heartwood, brown and soft rots were also prevalent, particularly in sapwood. Moreover, white rot and soft rot were positively and brown rot negatively correlated with wood pH. Ordination analyses clearly showed a succession of cryptogam species during log decomposition and showed significant correlations of communities with the pH, water content, and decay type of wood. These analyses indicate that fungal wood decomposer activities strongly influence the cryptogam communities on dead wood. 相似文献
4.
Herman Yeger 《Journal of cell communication and signaling》2015,9(1):105-107
Obesity has become a global problem affecting adults and children alike. Lifestyle choices both personal and industry driven can be blamed for the rise in obesity. One must distinguish between the possibly reversible overweight condition and the almost intractable actual morbid obesity where predisposing genetic factors may come into play. Both however exhibit consequences to health with a severity that cannot be underestimated. Deleterious changes to metabolism can lead to type II diabetes and atherosclerosis and other organ dysfunctions. It has long been recognized that there are two main types of fatty tissue in the body, white adipose tissue (WAT) serving a storage function and brown adipose tissue (BAT) serving a thermogenic function. The new discovery has been that WAT cells can be induced to undergo conversion (browning) to BAT to yield what is called beige adipose tissue, acquiring the thermogenic function. The clinical dream is to be able to promote browning and to induce, what may be called, burning off the fat. In this B&B article I entice the reader with a recent study that shows how two key hormones insulin and leptin operate cooperatively in the brain to monitor and regulate energy balance and the downstream effect of browning. I present other studies to add additional perspectives to the understanding of the mechanisms in peripheral tissues and other hormones that play additional key roles. Whether obesity can be conquered therapeutically by manipulating the regulatory systems is still an open question. 相似文献
5.
Infestation of arboreal nests of coatis by triatomine species,vectors of Trypanosoma cruzi,in a large Neotropical wetland 下载免费PDF全文
Juliane Saab de Lima Fabiana Lopes Rocha Fernanda Moreira Alves Elias Seixas Lorosa Ana Maria Jansen Guilherme de Miranda Mourão 《Journal of vector ecology》2015,40(2):379-385
The coati (Nasua nasua, Carnivora) is a medium‐sized mammal common in the Pantanal of Brazil. Unlike most mammals, coatis construct arboreal nests used for resting and reproduction. In this region, the coati is an important host of Trypanosoma cruzi, the causative agent of Chagas disease. There are two possible routes through coatis can be infected by T. cruzi: the oral route or the vectorial route. However, the relative importance of each of these routes in the infection of coatis and its role in the sylvatic cycle of the parasite are unknown. Our objectives were to investigate: (i) whether coati nests were infested by triatomine bugs, (ii) what species were frequent in the nests, (iii) whether the triatomines in nests were infected by T. cruzi, and (iv) what were the food resources of these triatomines. Eight of the 24 nests sampled were infested with triatomines, a total of 37 specimens of at least two species (Rhodnius stali and Triatoma sordida). In one nest, R. stali and T. sordida co‐occurred and both fed on multiple resources, including coatis. This is the first report of triatomines occurring in arboreal nests of coatis. The co‐occurrence of two different genera of triatomine vectors and coatis within the limited space of the coati nests provide multiple opportunities for the exchange of the protozoan parasite through both the vectorial and oral transmission routes. 相似文献
6.
Nilaparvata lugens, the brown planthopper (BPH) feeds on rice phloem sap, containing high amounts of sucrose as a carbon source. Nutrients such as sugars in the digestive tract are incorporated into the body cavity via transporters with substrate selectivity. Eighteen sugar transporter genes of BPH (Nlst) were reported and three transporters have been functionally characterized. However, individual characteristics of NlST members associated with sugar transport remain poorly understood. Comparative gene expression analyses using oligo-microarray and quantitative RT-PCR revealed that the sugar transporter gene Nlst16 was markedly up-regulated during BPH feeding. Expression of Nlst16 was induced 2 h after BPH feeding on rice plants. Nlst16, mainly expressed in the midgut, appears to be involved in carbohydrate incorporation from the gut cavity into the hemolymph. Nlst1 (NlHT1), the most highly expressed sugar transporter gene in the midgut was not up-regulated during BPH feeding. The biochemical function of NlST16 was shown as facilitative glucose transport along gradients. Glucose uptake activity by NlST16 was higher than that of NlST1 in the Xenopus oocyte expression system. At least two NlST members are responsible for glucose uptake in the BPH midgut, suggesting that the midgut of BPH is equipped with various types of transporters having diversified manner for sugar uptake. 相似文献
7.
《Cryobiology》2015,70(3):434-441
The adaptability of cryopreservation protocols for brown bear spermatozoa collected under field conditions and frozen in a nearby laboratory (transported for a few hours) or shipped to a reference laboratory for sex sorting (transported for a few days) was evaluated. Forty-nine electroejaculates from 15 mature brown bears were extended to 100 × 106 sperm/mL in a TES-Tris-Fructose based extender and cryopreserved (−20 °C/min to −100 °C and stored at −196 °C). After thawing, the quality of the seminal samples was assessed for total (TM), progressive (PM) motility and kinetic parameters – by CASA –, and viability (VIAB), viable and non-apoptotic status (YOPRO−), high membrane mitochondrial potential (MIT) and intact acrosomes (iACR) – by flow cytometry –. In Experiment 1, we assessed different storage times (0, 0.5, 1 – control –, 4–5, 7–8 and 11–12 h) at 5 °C from final dilution to freezing. After thawing, non-equilibrated samples (0 h) showed lower values of iACR, TM and PM. No significant differences were found for the different periods of equilibration tested. In Experiment 2, we evaluated three long-term storage times (24, 48 and 72 h) at 5 °C before freezing using storage for 1 h as control. The post-thawing quality of brown bear spermatozoa declined markedly after 48–72 h of pre-freezing. In conclusion, our findings suggest the possibility of extending the pre-freezing cooling period up to 24 h post-collection without freezing. This knowledge should enable the adaptation of the freezing protocols for when a special handling conditions are required such as the shipment of seminal samples to technological centers for the pre-freezing application of enhancer spermatic biotechnologies. 相似文献
8.
病毒侵染对西伯利亚百合DNA甲基化的影响 总被引:1,自引:0,他引:1
采用基于AFLP的甲基化敏感扩增多态性(MSAP)技术,用10对引物对侵染百合花叶病毒和丛簇病毒的西伯利亚百合植株和无毒植株进行DNA甲基化水平和模式分析.结果发现,西伯利亚百合无毒植株和病毒侵染植株的平均甲基化水平分别为40.1%和31.5%;平均全甲基化率分别为13.0%和9.7%;半甲基化率分别为27.1%和21.8%.研究表明,百合DNA甲基化多以半甲基化的形式存在;病毒侵染导致百合植株DNA甲基化水平降低,且对整体甲基化水平、全甲基化水平和半甲基化水平均产生了影响;说明病毒侵染百合后植株出现的症状在一定程度上与DNA甲基化存在关联. 相似文献
9.
David J.MABBERLEY 《植物分类与资源学报》2011,33(1):31-38
The history of botanic gardens in the United Kingdom is sketched out with particular reference to the Royal Botanic Gardens Kew and its changing role to meet societal requirements over 250 years.Kew’s position as a modern scientific institution confronting today’s environmental issues through its Breathing Planet Programme yet retaining its heritage buildings and collections is pinpointed. 相似文献
10.
The structural features of laminarans and galactofucans extracted from the brown seaweed Saccharina longicruris were determined for four harvest periods (M05, A05, N05 and J06). Crude laminarans were purified and crude galactofucans were fractionated using DEAE Sepharose anion exchange chromatography with increasing levels of NaCl (0.5, 1 and 2 M). The results showed differences in terms of their monosaccharide compositions. Purified laminaran contained a high proportion of d-glucose, between 45.1% and 69.1%, with a higher amount in M05 and A05, while the amount of d-mannitol remained constant (less than 1.7%). Crude galactofucans from M05, A05, and N05 contained 19.9-21.5% of sulphates, where J06 had only 14.3%. The 2 M fractionated galactofucans contained a higher proportion of sulphate groups, from 27.1% to 36.9%, for each harvest period, while the 1 M fraction contained 9.2% to 15.9% of sulphates. An important variation in the amount of l-fucose and d-galactose was observed for crude and fractionated galactofucans. In M05, a higher content of l-fucose was observed for crude galactofucans compared to that observed for d-galactose (21.5% vs. 11.1%), whereas the opposite was found for A05 (18.5% vs. 36.6%), N05 (20.9% vs. 36.8%), and J06 (12.8% vs. 19.6%). Also, the 0.5 and 2 M fractions were similar to the crude galactofucans. A05, N05, and J06 contained lower amounts of l-fucose than d-galactose, while the M05 fractions showed the opposite behaviour. However, the 1 M fraction showed a higher amount of l-fucose than d-galactose for each harvest period. The next step will be to study the biological activity of the fractions and to attempt to relate this activity to the structure of the galactofucan and laminaran fractions. 相似文献