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1.
Oceanic islands are productive habitats for generating new species and high endemism, which is primarily due to their geographical isolation, smaller population sizes and local adaptation. However, the short divergence times and subtle morphological or ecological divergence of insular organisms may obscure species identity, so the cryptic endemism on islands may be underestimated. The endangered weevil Pachyrhynchus sonani Kôno (Coleoptera: Curculionidae: Entiminae: Pachyrhynchini) is endemic to Green Island and Orchid Island of the Taiwan‐Luzon Archipelago and displays widespread variation in coloration and host range, thus raising questions regarding its species boundaries and degree of cryptic diversity. We tested the species boundaries of P. sonani using an integrated approach that combined morphological (body size and shape, genital shape, coloration and cuticular scale), genetic (four genes and restriction site‐associated DNA sequencing, RAD‐seq) and ecological (host range and distribution) diversity. The results indicated that all the morphological datasets for male P. sonani, except for the colour spectrum, reveal overlapping but statistically significant differences between islands. In contrast, the morphology of the female P. sonani showed minimum divergence between island populations. The populations of P. sonani on the two islands were significantly different in their host ranges, and the genetic clustering and phylogenies of P. sonani established two valid evolutionary species. Integrated species delimitation combining morphological, molecular and ecological characters supported two distinct species of P. sonani from Green Island and Orchid Island. The Green Island population was described as P. jitanasaius sp.n. Chen & Lin, and it is recommended that its threatened conservation status be recognized. Our findings suggest that the inter‐island speciation of endemic organisms inhabiting both islands may be more common than previously thought, and they highlight the possibility that the cryptic diversity of small oceanic islands may still be largely underestimated.  相似文献   
2.
有关赤眼蜂种鉴别的商榷   总被引:2,自引:0,他引:2  
曾省 《昆虫学报》1965,(4):404-410
Quednan,W.在1956、1960年连续发表文章,提出用生物学特性的标准来辨别赤眼蜂种或生态型,是具有一定科学意义的,但忽视雄外生殖器的构造。石井悌(Ishii,T.,1941)曾建议根据雄虫外生殖器的构造来区别几种赤眼蜂,并成立两个新种,即Trichogramma chilonis与T.jezoensis。因为制片的关系,雄外生殖器构造部分看不清楚,故他所绘的图是不甚完善的;作者现改进了制片方法,使赤眼蜂雄外生殖器内部构造,在显微镜检视下较为明显,特为补充,重行描述,并取北京地区玉米螟卵赤眼蜂(T.chilonis)与桃捲叶蛾卵赤眼蜂(T.minutum)作为典型,以资比较。同时发现这两种赤眼蜂的前翅毛列与稻螟赤眼蜂(T.japonicum)有显著的差异,特别是第6条纵毛行与第8条横毛行汇合处,前者有缺口,呈倒“八”字形,后者无缺口,呈倒“人”字形(图2,A、B);而且稻螟赤眼蜂雄外生殖器内不具“针”,故不同意Quednau把T.chilonis并入T.japonicum种内作为“同物异名”,而应该维持石井悌的T.chilonis 仍为—个独立种。 作者1963,年在辽宁省丹东市郊区于柞蚕卵内发现一种食胎赤眼蜂(Trichogramma embryophagum (Hartig)),在国内为初次记载,确是产雌性孤雌生殖型。  相似文献   
3.
利用人粒细胞集落刺激因子(hG-CSF)cDNA3′端非翻译区(3′-UTR)中存在的DraⅠ酶切位点,通过部分酶切与完全酶切,删除3′-UTR不同长度,构建了四种hG-CSFcDNA瞬时重组表达质粒。转染COS-7细胞后,生物活性测定结果提示,hG-CSFcDNA3′-UTR对其表达起负调控作用,其关键性序列位于紧接终止密码子TGA下游的65bp范围内,3′-UTR对hG-CSFcDNA表达的影响与转录水平的差别有一定关系。  相似文献   
4.
在神经管形成的过程中,从原肠晚期到神经管即将关闭,我们观察了预定神经上皮和神经上皮细胞的细胞连接。我们的结果和过去的报道不同,我们看到紧密连接和间隙连接在所观察的各个时期一直存在,而且它们是处于持续的形态变化之中,就此论证了紧密连接在神经管形态建成中的作用,并讨论了紧密连接和间隙连接的相互关系。  相似文献   
5.
卢筝 《昆虫学报》1979,(4):477-477
麦长腿红蜘蛛Petrobia latens Muller 雄虫 身体梨形。长459微米,宽272微米。身体背面具极细的指纹状刻纹,在油镜下才能看见。背刚毛短,纺锤形,具茸毛。前肢体段前毛长15μ;中毛长18μ;后毛长28μ;肩毛长27μ;三对背中毛的长度由前向后依次为28μ、25μ、25μ;三对背侧毛的长度与背中毛相等;荐毛和攫毛长24μ(图1)。  相似文献   
6.
Summary

The site of yolk protein synthesis in crustaceans has long been a subject of controversy. A portion of the vitellogenin gene structure was reported recently in a freshwater giant prawn (Macrobrachium rosenbergii) and black tiger shrimp (Penaeus monodori), in which the hepatopancreas was confirmed to be the extraovarian site of vitellogenin synthesis. The ovary is also frequently reported to be the site of yolk protein synthesis in penaeid shrimp. The same PCR product was obtained using cDNA from the hepatopancreas or the ovary as a template. The deduced amino acid sequence of Vg in P. vannamei showed high identities of 57% and 78% with those from M. rosenbergii and P. monodon, respectively. The same location of the intron in the sequenced region of genomic DNA was also found between these three species. We therefore concluded that the hepatopancreas and ovary are sites of vitellogenin synthesis in P. vannamei. The partial structure of the vitellogenin gene is further presented.  相似文献   
7.
The relative simplicity of the mandible and its functional integration with the upper dentition in carnivorans makes it an ideal subject for functional morphological studies. To compare the mandibular biomechanics of two convergently evolved bone‐cracking ecomorphologies, we used finite element modelling to analyse mandibular corpus stress. The bone‐cracking spotted hyena Crocuta crocuta was used as a living analogue to the late Miocene percrocutid Dinocrocuta gigantea, using the grey wolf Canis lupus as a molar bone‐crushing outgroup. Mandibular stress values during p3, p4, and m1 tooth biting are found to be lowest in Cr. crocuta, and elevated in both Ca. lupus and D. gigantea. However, the stress‐dissipation patterns of the pre‐m1 corpus are similar between Cr. crocuta and D. gigantea. Lastly, D. gigantea has a relatively weaker corpus at the post‐m1 position than either Cr. crocuta or Ca. lupus. These findings suggest that even though stress patterns are similar amongst the bone‐cracking ecomorphs, the extinct D. gigantea had a weaker mandibular structure when performing a comparable bone‐cracking task as in Cr. crocuta because of its slender post‐m1 corpus. Ontogeny could potentially play an important role in strengthening the post‐m1 corpus by growth in the dorsoventral axis, and continuous increase in biting performance through adulthood in living Cr. crocuta suggests the possibility of a relatively more delayed development to full bone‐cracking capability in D. gigantea. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 158 , 683–696.  相似文献   
8.
Xing, L, Bell, P.R., Currie, P.J., Shibata, M., Tseng, K. & Dong, Z. 2012: A sauropod rib with an embedded theropod tooth: direct evidence for feeding behaviour in the Jehol group, China. Lethaia, Vol. 45, pp. 500–506. A fragmentary rib from the Lower Cretaceous (Barremian) Yixian Formation in northeastern China preserves rare, direct evidence of feeding behaviour by an unidentified theropod. The rib, which comes from the holotype of Dongbetitan, preserves an embedded, broken theropod tooth. Comparison of the tooth with all known theropods from the Yixian Formation suggests that it belongs to a new taxon of medium‐sized theropod. Given the large size difference between the sauropod and the theropod and the absence of reactive bone growth around the tooth, the bite likely occurred post‐mortem during scavenging. Recognition of a new, medium‐sized theropod increases the known diversity of taxa from the Yixian Formation and helps fill a gap in the theropod palaeoecology of that formation, which previously consisted of only small (<2 m) forms. □China, Cretaceous, feeding behaviour, theropod, titanosauriformes, sauropod.  相似文献   
9.
为从生理生化水平上探讨二化螟滞育幼虫应对温度胁迫的生理机制,分别对系列温度胁迫(STS)和梯度温度胁迫(GTS)处理后的幼虫水、脂质、总糖、小分子碳水化合物含量及超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性进行了测定.结果表明:随着温度的降低,两种处理二化螟滞育幼虫虫体含水量趋于减少,且0℃以下时GTS处理下降幅度较STS处理显著;两种处理脂质含量均逐步下降且二者间无显著差异;两种处理总糖含量分别先减后增和持续下降,均检测出4种小分子碳水化合物,其中STS处理葡萄糖、甘油和果糖含量先增后减,海藻糖含量变化与此相反,而GTS处理海藻糖含量先减后增,葡萄糖和甘油含量呈相反变化,果糖含量无变化;14~-14℃范围内STS处理SOD和POD活性较GTS处理低,CAT活性相反.二化螟滞育幼虫生理指标的变化反映了其应对不同温度胁迫的生理响应.  相似文献   
10.
A wound‐inducible cDNA, ipomoelin (IPO) was isolated from the subtraction library of sweet potato (Ipomoea batatas cv. Tainung 57) and used as a molecular probe to investigate the transduction pathway of wounding signal within plant cells. Following mechanical wounding of the leaves of sweet potato, IPO mRNA accumulation peaked at 6 h and then continuously declined. However, IPO gene expression in the apical unwounded leaves began at 6 h after wounding and continued for a further 10 h. Besides mechanical wounding, methyl jasmonate (MeJA) was identified as a signal transducer leading to the accumulation of IPO mRNA. Treatment with salicylic acid reduced the production of IPO mRNA, further supporting the involvement of the octadecanoid pathway in the signal transduction of wounding in sweet potato. In addition, ethylene was involved in the signal pathway and induced the expression of the IPO gene. Furthermore, the application of okadaic acid, a protein phosphatase inhibitor, blocked the accumulation of IPO mRNA induced by MeJA or ethylene, indicating that activation of the IPO gene by both MeJA and ethylene was via dephosphorylated proteins. The presence of a calcium ion chelator or channel blockers also inhibited the expression of the IPO gene after wounding. However, investigation by confocal scanning microscopy further pointed out that mechanical wounding rather than the application of MeJA induced the accumulation of the calcium ion. These results may indicate that the calcium ion is also involved in the activation of IPO mRNA. In addition, wounding signals the accumulation of calcium ion first and then stimulates the biosynthesis of MeJA in sweet potato. Hence, the reaction sequence of signal transducers, including the calcium ion, MeJA and protein kinase/phosphatase, in the wounding signalling pathway of sweet potato is suggested in this report.  相似文献   
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