bluuebunny/crossref_metadata_2025 huggingface dataset:
Sexual and Apomictic Seed Formation in Hieracium Requires the Plant Polycomb-Group Gene FERTILIZATION INDEPENDENT ENDOSPERM
Authors: Rodrigues Julio C.M. , Tucker Matthew R. , Johnson Susan D. , Hrmova Maria , Koltunow Anna M.G.
Published: September 2008

A Polycomb-Group (PcG) complex, FERTILIZATION INDEPENDENT SEED (FIS), represses endosperm development in Arabidopsis thaliana until fertilization occurs. The Hieracium genus contains apomictic species that form viable seeds asexually. To investigate FIS function during apomictic seed formation, FERTILIZATION INDEPENDENT ENDOSPERM (FIE), encoding a WD-repeat member of the FIS complex, was isolated and downregulated in sexual and apomictic Hieracium species. General downregulation led to defects in leaf and seed development, consistent with a role in developmental transitions and cell fate. PcG-like activity of Hieracium FIE was also supported by its interaction in vitro with the Arabidopsis CURLY LEAF PcG protein. By contrast, specific downregulation of FIE in developing seeds of sexual Hieracium did not result in autonomous endosperm proliferation but led to seed abortion after cross-pollination. Furthermore, in apomictic Hieracium, specific FIE downregulation inhibited autonomous embryo and endosperm initiation, and most autonomous seeds displayed defective embryo and endosperm growth. Therefore, FIE is required for both apomictic and fertilization-induced seed initiation in Hieracium. Since Hieracium FIE failed to interact with FIS class proteins in vitro, its partner proteins might differ from those in the FIS complex of Arabidopsis. These differences in protein interaction were attributed to structural modifications predicted from comparisons of Arabidopsis and Hieracium FIE molecular models.
Computational models explain the oligosaccharide specificity of cyanovirin‐N
Authors: Fujimoto Yukiji K. , TerBush Ryan N. , Patsalo Vadim , Green David F.
Published: September 2008

The prokaryotic lectin cyanovirin‐N (CV‐N) is a potent inhibitor of HIV envelope‐mediated cell entry, and thus is a leading candidate among a new class of potential anti‐HIV microbicides. The activity of CV‐N is a result of interactions with the D1 arm of high‐mannose oligosaccharides on the viral glycoprotein gp120. Here, we present computationally refined models of CV‐N recognition of the di‐ and trisaccharides that represent the terminal three sugars of the D1 arm by each CV‐N binding site. These models complement existing structural data, both from NMR spectroscopy and X‐ray crystallography. When used with a molecular dynamics/continuum electrostatic (MD/PBSA) approach to compute binding free energies, these models explain the relative affinity of each site for the two saccharides. This work presents the first validation of the application of continuum electrostatic models to carbohydrate–protein association. Taken as a whole, the results both provide models of CV‐N sugar recognition and demonstrate the utility of these computational methods for the study of carbohydrate‐binding proteins.
Structural requirements for calmodulin binding to membrane‐associated guanylate kinase homologs
Authors: Paarmann Ingo , Lye Ming F. , Lavie Arnon , Konrad Manfred
Published: September 2008

Effector molecules such as calmodulin modulate the interactions of membrane‐associated guanylate kinase homologs (MAGUKs) and other scaffolding proteins of the membrane cytoskeleton by binding to the Src homology 3 (SH3) domain, the guanylate kinase (GK) domain, or the connecting HOOK region of MAGUKs. Using surface plasmon resonance, we studied the interaction of members of all four MAGUK subfamilies—synapse‐associated protein 97 (SAP97), calcium/calmodulin‐dependent serine protein kinase (CASK), membrane palmitoylated protein 2 (MPP2), and zona occludens (ZO) 1—and calmodulin to determine interaction affinities and localize the binding site. The SH3‐GK domains of the proteins and derivatives thereof were expressed in E. coli and purified. In all four proteins, high‐affinity calmodulin binding was identified. CASK was shown to contain a Ca2+‐dependent calmodulin binding site within the HOOK region, overlapping with a protein 4.1 binding site. In ZO1, a Ca2+‐dependent calmodulin binding site was detected within the GK domain. The equilibrium dissociation constants for MAGUK–calmodulin interaction were found to range from 50 nM to 180 nM. Sequence analyses suggest that binding sites for calmodulin have evolved independently in at least three subfamilies. For ZO1, pulldown of GST‐calmodulin was shown to occur in a calcium‐dependent manner; moreover, molecular modeling and sequence analyses predict conserved basic residues to be exposed on one side of a helix. Thus, calmodulin binding appears to be a common feature of MAGUKs, and Ca2+‐activated calmodulin may serve as a general regulator to affect the interactions of MAGUKs and various components of the cytoskeleton.
Winter range compression of migrants in Central America
Authors: Mills Alexander M.
Published: September 2008

Where there is seasonal disparity among opportunities, the season with those in shortest supply is most likely to limit populations. Among migrant birds that travel between different breeding and winter ranges, any of breeding, migratory or winter conditions could exclusively constitute such population‐limiting factors. In both the New and Old Worlds, landmass is disproportionately concentrated in temperate latitudes. In the Americas, most passerine bird species that breed in the USA and Canada spend the winter further south, commonly in parts of the tropics where landmass is significantly less. Using a sample of 89 migratory species (eight passerine families) that breed in eastern North America, I considered patterns of geographic breeding range size, winter range size and winter distribution. Winter range size is usually smaller than breeding range size (84 of 89 species), often substantially so (minimum 8%, mean 52%). Wintering latitude explains significant variation in both breeding range size and winter range size, as well as in winter range size relative to breeding range size. In particular, all three measures vary latitudinally in patterns similar to latitudinal variation in landmass. These patterns collectively suggest that the reduction in landmass in the latitudes of Central America and the Caribbean is a limiting factor for migrant bird populations, adding to other research concluding that winter conditions sometimes prevail over breeding conditions in the limitation of populations. Hectare for hectare, habitat destruction in the tropics is likely to have the greater impact on the welfare of passerine populations breeding in North America.
Increasing prevalence of avian poxvirus in Darwin's finches and its effect on male pairing success
Authors: Kleindorfer Sonia , Dudaniec Rachael Y.
Published: September 2008

Island populations harbour a comparatively species‐poor pathogen community, often resulting in naïve host species that experience compromised immunity when faced with novel diseases. Over 95% of the Galápagos avifauna have survived 400 years of human settlement, yet currently face threats due to introduced diseases such as avian poxvirus. On Hawaii, declining populations of birds and even some extinctions have been attributed to avian poxvirus, and hence, identifying the prevalence and fitness costs of avian poxvirus on the Galápagos is a conservation priority. Surveys of avian poxvirus in Darwin's finches on Santa Cruz Island between 2000 and 2004 found a 33% annual increase in the prevalence of pox lesions in ground finches. Comparisons of pox prevalence on three islands (Santa Cruz, Floreana, and Isabela) were made in 2004, which indicated significant variation in pox prevalence across islands (Isabela>Santa Cruz>Floreana). Darwin's finch species were found to be differentially affected by poxvirus, with a higher prevalence in ground finches than in tree finches. There was a significant effect of habitat, even within species, with higher prevalence in the lowlands than highlands. Pox prevalence was not correlated with sex or body condition. However, male small ground finchesGeospiza fuliginosawith evidence of pox were less likely to have a mate (16.6% paired) compared with males without pox (77% paired), indicating fitness costs associated with poxvirus infection.
Whip it good! Geographic consistency in male songs and variability in female songs of the duetting eastern whipbird Psophodes olivaceus
Authors: J. Mennill Daniel , C. Rogers Amy
Published: September 2008

Geographic variation in male bird songs has been studied extensively, but there have been few investigations of geographic variation in female songs or sex differences in patterns of geographic variation. We compared patterns of variation in male and female songs of eastern whipbirds Psophodes olivaceus by analyzing recordings from 16 populations across the species’ geographic range in eastern Australia. We found remarkably different patterns of geographic variation between the sexes. Female eastern whipbird songs are easily categorized into discrete song types. Song types are shared between nearby females, but female songs show pronounced differences at a continental scale. In contrast, male eastern whipbird songs show high consistency throughout the species’ geographic range. All recorded males share the ability to transpose the frequency of the introductory whistle and most recorded males share the ability to vary the direction of the slope of the terminal whip crack. For eight of nine measured variables, female songs show significantly higher levels of variation than male songs. We discuss whether sex differences in dispersal, song learning strategies, and song function may explain these sex differences in patterns of song variation. We suggest that eastern whipbirds have experienced a decoupling of male and female song learning strategies and that the songs of each sex have responded to different selective pressures in the context of countersinging interactions. We speculate that consistency in male songs throughout the geographic range of eastern whipbirds may arise through female preference for males that perform large bandwidth whip cracks.
Using stable isotope analysis to determine the winter moult extent in migratory birds: the complex moult of Savi's warblers Locustella luscinioides
Authors: Neto Júlio M. , Newton Jason , Gosler Andrew G. , Perrins Christopher M.
Published: September 2008

Patterns of feather wear in birds captured in spring have traditionally been analysed to describe the extent of winter moult in long‐distance migrants. However, the interpretation of feather wear may be rendered extremely difficult due to long moult periods, by the progress of the season, and by the existence of complex moult patterns. Here, stable isotope analysis is used to determine the origin of the wing feather generations present in Savi's warblers Locustella luscinioides captured in Portugal. Carbon, nitrogen and hydrogen isotope ratios of feathers of known European origin differed significantly from those known to have grown in Africa. A discriminant analysis, in which 91.1% of the cross validated samples were correctly classified, was used to determine the origin of tail and wing feathers collected from birds caught when they returned to the breeding quarters. The interpretation of feather‐wear generally agreed with the stable isotope analysis, but some inconsistencies were identified. The extent of winter moult in Savi's warblers is described and its moult strategy discussed.
Brightness variability in the white badge of the eagle owlBubo bubo
Authors: Penteriani Vincenzo , Alonso‐Alvarez Carlos , Del Mar Delgado María , Sergio Fabrizio , Ferrer Miguel
Published: September 2008

The application of modern spectrometry to the study of avian colour variability has revealed ignored patterns of colour variation such as male‐biased sexual dichromatism and seasonal variability in the plumage. However, the variation in the achromatic property of such traits, that is in the total light reflectance of the spectrum (i.e., brightness), has commonly been overlooked. The evolution of signals based on brightness should be favoured in those species that are active when light is scarce, i.e. at dawn and dusk. The eagle owlBubo bubois monogamous and apparently monomorphic in plumage‐coloration. In this species, sexual and territorial call behaviour is mainly performed at dawn and dusk, during which a white patch on the throat is repeatedly exposed at each call. We measured the total light reflectance of the feathers of this badge in 39 eagle owl specimens from museum collections. We found seasonal variability and sexual dichromatism in the brightness of the plumage badge. The total reflectance of this trait peaked during the territorial‐mating period. Moreover, females showed higher values of brightness than males, in agreement with the reversed body size dimorphism present in this and many other raptor species. Finally, female but not male body size was positively correlated with white badge reflectance.
No sexual differences in embryonic period in jackdawsCorvus monedulaand black‐headed gullsLarus ridibundus
Authors: Martijn Salomons H. , Müller Wendt , Dijkstra Cor , M. Eising Corine , Verhulst Simon
Published: September 2008

Offspring survival probability usually decreases with hatching order, especially in species with brood reduction. Brood reduction in combination with a sex difference in embryonic period (the time between laying and hatching of an egg) can potentially have a profound effect on sex allocation, with higher investment in chicks of the early hatching sex because they are more likely to survive to fledge. Two recent studies reported sex differences in the embryonic period, but compared embryonic period between, rather than within, clutches, which does not control for possible environmental effects on both clutch sex ratio and embryonic period. We compared the embryonic period of sons and daughters within clutches in jackdawsCorvus monedulaand black‐headed gullsLarus ridibundus, two species with frequent brood reduction, and found no sexual difference in embryonic period. This suggests that sex allocation is not affected by sex differences in embryonic period in these species, but more studies are required to verify whether this is a general pattern.
Enhancement of apoptotic damage of squamous cell carcinoma cells by inhibition of the mitochondrial DNA repairing system
Authors: Ueta Eisaku , Sasabe Eri , Yang Zhu , Osaki Tokio , Yamamoto Tetsuya
Published: September 2008

Mitochondrial DNA (mtDNA) repair systems are thought to be associated with the susceptibility of cancer cells to anticancer agents. The present study investigated the relationship between the susceptibility to γ‐rays and the mtDNA repair ability of oral squamous cell carcinoma (OSC) cell lines. The levels of 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG) and mtDNA common deletion in both nuclear and mitochondrial DNA of OSC‐2, OSC‐3 and OSC‐6 cells (radio‐sensitive cell lines) after γ‐ray‐irradiation were higher than those of OSC‐1, OSC‐4 and OSC‐5 cells (radio‐resistant cell lines). Compared with OSC‐2, OSC‐3 and OSC‐6 cells, OSC‐1, OSC‐4 and OSC‐5 cells had higher levels of activity of phosphoinositide‐3 kinase (PI‐3K)/Akt and more strongly expressed 8‐hydroxyguanine DNA glycosylase (OGG1), DNA polymerase γ (POLG) and mitochondrial transcription factor A (Tfam). Down‐regulation of these mtDNA‐repair‐associated molecules by the RNA interference technique enhanced the susceptibility of OSC‐2 and OSC‐5 cells to γ‐rays, and the expression of Tfam and POLG was down‐regulated by inhibitors of PI‐3K/Akt signaling. These results indicate that the inhibition of mtDNA repair capacity by PI‐3K/Akt signal inhibitors and OGG1 down‐regulator in cancer cells may be a useful strategy for cancer treatment when combined with ionizing irradiation and chemotherapeutic drugs. (Cancer Sci 2008; 99: 2230–2237)
Hepatoma‐derived growth factor involved in the carcinogenesis of gastric epithelial cells through promotion of cell proliferation by Erk1/2 activation
Authors: Mao Jianshan , Xu Zefeng , Fang Yongming , Wang Haijun , Xu Jinghong , Ye Jinjia , Zheng Shu , Zhu Yongliang
Published: September 2008

Hepatoma‐derived growth factor (HDGF) is related to tumorigenesis and the development of cancer; it is an independent factor associated with the prognosis of liver cancer, non‐small cell lung cancer and pancreatic cancer. However, the molecular mechanism by which HDGF participates in gastric carcinogenesis and development as well as its functional regulation during the development of gastric precancerous lesions needs to be further analyzed. In the present study, we analyzed the effect of HDGF transfection on the proliferation and on the changes of mitogen‐activated protein kinase (MAPK), Akt, and nuclear factor‐κB (NF‐κB) pathways in gastric cancer AGS cells. HDGF transfection significantly activated Erk1/2 in AGS cells and promoted anchorage‐independent growth. Further studies showed that HDGF expression gradually increased in the gastric carcinogenesis process and HDGF showed a high expression in poorly differentiated adenocarcinoma prone to lymphoid metastasis; these findings suggest that HDGF is involved in the gastric carcinogenesis process and promotes proliferation and metastasis via Erk1/2 activation. (Cancer Sci 2008; 99: 2120–2127)
DCUN1D3, a novel UVC‐responsive gene that is involved in cell cycle progression and cell growth
Authors: Ma Teng , Shi Taiping , Huang Jing , Wu Lina , Hu Fanlei , He PengFei , Deng WeiWei , Gao Peng , Zhang Yingmei , Song Quansheng , Ma Dalong , Qiu Xiaoyan
Published: September 2008

DCUN1D3 (DCN1, defective in cullin neddylation 1, domain containing 3) was found during the process of high throughput screening of novel human genes associated with serum response element (SRE) pathway activation. The DCUN1D3 gene is highly conserved among vertebrates. Human DCUN1D3 complementary DNA (cDNA) encodes 304 amino acids with an apparent molecular mass of 34 kDa. However, there has been no report about the function of DCUN1D3. This study detected that DCUN1D3 was broadly expressed in several tumor tissues and cultured cell lines; however, UVC irradiation of different doses significantly increased DCUN1D3 expression level in these cancer cell lines. Over‐expression of the DCUN1D3 inhibits cell growth in HeLa. When the DCUN1D3 gene was silenced by siRNA in UVC‐treated HeLa, the cell cycle in S phase was remarkably blocked; furthermore, the UVC‐induced cell death was inhibited. In addition, DCUN1D3 localized mainly in the cytoplasm and perinuclear, but after UVC treatment, the DCUN1D3 gradually entered the nucleus. All the results above indicate that DCUN1D3 is a novel UVC‐response gene involved in cell cycle regulation and cell survival. (Cancer Sci 2008; 99: 2128–2135)
Autophagy and autophagic cell death are next targets for elimination of the resistance to tyrosine kinase inhibitors
Authors: Mishima Yuko , Terui Yasuhito , Mishima Yuji , Taniyama Akiko , Kuniyoshi Ryoko , Takizawa Toshihiro , Kimura Shinya , Ozawa Keiya , Hatake Kiyohiko
Published: September 2008

Autophagy, a cellular degradation system has been demonstrated in some hematopoietic malignant cell lines, but there is much still remaining to be known about its role and the mechanisms. We observed the excessive autophagy in chronic myelogenous leukemia (CML) cell line, K562, associated with treatment of 12‐O‐tetradecanoyl‐phorbol‐13‐acetate (TPA), which can induce K562 cells to differentiate into megakaryocytic lineage. Confocal microscopic analysis demonstrated that autophagic cells did not express a megakaryocyte marker, the CD41 molecule, indicating that the autophagy was independent of megakaryocytic differentiation. After remarkable autophagic degradation, the cells finally underwent autophagic cell death (APCD). On the other hand, a block of TPA‐induced autophagy by chloroquine rapidly promoted cell death that was not APCD. This result suggested that autophagy regulated two mechanisms in K562 cells: both the cell survival system and APCD. To confirm that autophagy regulates the cell survival system in K562 cells, imatinib was used to induce cell death in K562 cells. Autophagy has not been considered during imatinib treatment; nonetheless, co‐treatment with imatinib and chloroquine markedly enhanced imatinib‐induced cell death, compared to K562 cells treated only with imatinib. Furthermore, imatinib‐resistant cell lines, BaF3/T315I and BaF3/E255K, also underwent cell death by co‐treatment with imatinib and chloroquine. From these data, we concluded that autophagy is deeply related to the cell survival system and that inhibition of autophagy accelerates TPA‐ or imatinib‐induced cell death. The block of autophagy could be a new strategy in the treatment of CML. (Cancer Sci 2008; 99: 2200–2208)
Antitumor and antimetastatic actions of anthrone‐C‐glucoside, cassialoin isolated from Cassia garrettiana heartwood in colon 26‐bearing mice
Authors: Kimura Yoshiyuki , Sumiyoshi Maho , Taniguchi Masahiko , Baba Kimiye
Published: September 2008

We examined the antitumor and antimetastatic actions of 10‐hydroxy‐anthrone‐C‐glucoside cassialoin isolated from Cassia garrettiana heartwood in colon 26‐bearing mice. Cassialoin (5 and 10 mg/kg) inhibited tumor growth and metastasis to the abdomen and the expression of CD31 (angiogenesis marker) in the tumors, and it increased the numbers of the γ‐interferon (IFN‐γ)‐positive, CD8+ T and natural killer cells in the small intestine or spleen of colon 26‐bearing mice. Furthermore, cassialoin inhibited tumor‐induced angiogenesis in colon 26‐packed chamber‐bearing mice. We examined the metabolic activities in the blood, stomach and small intestine after p.o. administration of cassialoin to mice. These results suggest that cassialoin might be converted to chrysophanol through chrysophanol‐9‐anthrone and metabolized to aloe‐emodin from chrysophanol. Chrysophanol‐9‐anthrone inhibited vascular endothelial growth factor (VEGF) and matrix metallopeptidase‐9 expression in colon 26 cells at 5 and 10 µM, and it inhibited VEGF‐induced angiogenesis and migration in human umbilical vein endothelial cells (HUVEC) at 0.5–10 µM. Furthermore, chrysophanol‐9‐anthrone inhibited VEGF receptor (VEGFR)‐2 expression and VEGF‐induced VEGFR‐2 phosphorylation. Aloe‐emodin also inhibited the VEGF‐induced angiogenesis by HUVEC at 1–100 µM. Cassialoin, chrysophanol‐9‐anthrone and aloe‐emodin enhanced concanavalin A‐induced IFN‐γ production in splenocytes of colon 26‐bearing mice at a low concentration of 0.1 µM. From these results, it is suggested that the antitumor and antimetastatic actions of p.o. administered cassialoin may be partly due to cassialoin and its metabolites such as chrysophanol‐9‐anthrone and aloe‐emodin through their anti‐angiogenic activities and/or the modulation of the immune systems in the spleen and small intestine in tumor‐bearing mice. (Cancer Sci 2008; 99: 2336–2348)
Somatostatin receptor‐1 induces cell cycle arrest and inhibits tumor growth in pancreatic cancer
Authors: Li Min , Wang Xiaochi , Li Wei , Li Fei , Yang Hui , Wang Hao , Brunicardi F. Charles , Chen Changyi , Yao Qizhi , Fisher William E.
Published: September 2008

Functional somatostatin receptors (SSTR) are lost in human pancreatic cancer. Transfection of SSTR‐1 inhibited pancreatic cancer cell proliferation in vitro. We hypothesize that stable transfection of SSTR‐1 may inhibit pancreatic cancer growth in vivo possibly through cell cycle arrest. In this study, we examined the expression of SSTR‐1 mRNA in human pancreatic cancer tissue specimens, and investigated the effect of SSTR‐1 overexpression on cell proliferation, cell cycle, and tumor growth in a subcutaneous nude mouse model. We found that SSTR‐1 mRNA was downregulated in the majority of pancreatic cancer tissue specimens. Transfection of SSTR‐1 caused cell cycle arrest at the G0/G1 growth phase, with a corresponding decline of cells in the S (mitotic) phase. The overexpression of SSTR‐1 significantly inhibited subcutaneous tumor size by 71% and 43% (n = 5, P < 0.05, Student's t‐test), and inhibited tumor weight by 69% and 47% (n = 5, P < 0.05, Student's t‐test), in Panc‐SSTR‐1 and MIA‐SSTR‐1 groups, respectively, indicating the potent inhibitory effect of SSTR‐1 on pancreatic cancer growth. Our data demonstrate that overexpression of SSTR‐1 significantly inhibits pancreatic cancer growth possibly through cell cycle arrest. This study suggests that gene therapy with SSTR‐1 may be a potential adjuvant treatment for pancreatic cancer. (Cancer Sci 2008; 99: 2218–2223)
TS‐1 enhances the effect of radiotherapy by suppressing radiation‐induced hypoxia‐inducible factor‐1 activation and inducing endothelial cell apoptosis
Authors: Zeng Lihua , Ou Guangfei , Itasaka Satoshi , Harada Hiroshi , Xie Xuejun , Shibuya Keiko , Kizaka‐Kondoh Shinae , Morinibu Akiyo , Shinomiya Kazumi , Hiraoka Masahiro
Published: September 2008

The therapeutic effect of concurrent chemoradiotherapy with TS‐1 has been confirmed in various solid tumors; however, the detailed mechanism of action has not yet been fully elucidated. In the present study, we identified hypoxia‐inducible factor‐1 (HIF‐1) as one of the targets of TS‐1 in chemoradiotherapy. In growth delay assays using a tumor xenograft of non‐small‐cell lung carcinoma, H441, TS‐1 treatment enhanced the therapeutic effect of single γ‐ray radiotherapy (14 Gy) and significantly delayed tumor growth by 1.58‐fold compared to radiotherapy alone (P < 0.01). An optical in vivo imaging experiment using a HIF‐1‐dependent 5HRE‐luc reporter gene revealed that TS‐1 treatment suppressed radiation‐induced activation of HIF‐1 in the tumor xenografts. The suppression led to apoptosis of endothelial cells resulting in both a significant decrease in microvessel density (P < 0.05; vs radiation therapy alone) and a significant increase in apoptosis of tumor cells (P < 0.01; vs radiation therapy alone) in tumor xenografts. All of these results indicate that TS‐1 enhances radiation‐induced apoptosis of endothelial cells by suppressing HIF‐1 activity, resulting in an increase in radiosensitivity of the tumor cells. Our findings strengthen the importance of both HIF‐1 and its downstream gene, such as vascular endothelial cell growth factor, as therapeutic targets to enhance the effect of radiotherapy. (Cancer Sci 2008; 99: 2327–2335)
Frequent aberrant methylation of the promoter region of sterile α motif domain 14 in pulmonary adenocarcinoma
Authors: Sun Weihong , Iijima Tatsuo , Kano Junko , Kobayashi Hiromi , Li Dongping , Morishita Yukio , Okubo Chigusa , Anami Yoichi , Noguchi Masayuki
Published: September 2008

Aberrant methylation of promoter CpG islands is known to be a major inactivation mechanism of tumor‐suppressor and tumor‐related genes. In order to identify novel hypermethylated genes in early stage lung adenocarcinoma, we carried out methylated CpG island amplification, modified suppression subtractive hybridization, and methylation‐specific polymerase chain reaction to identify aberrant methylation of CpG islands in the A/J mouse lung adenoma model, which histologically mimics the early stage of human pulmonary adenocarcinoma. Through methylated CpG island amplification, suppression subtractive hybridization, and differential screening, we detected five genes, three of which have human homologs. Two of them showed downregulation of their expression in human lung adenocarcinoma. Of these two genes, we selected sterile α motif domain 14 (SAMD14) and further analyzed its methylation status and expression level by methylation‐specific polymerase chain reaction and quantitative real‐time polymerase chain reaction. Most of the lung adenocarcinoma cell lines showed suppressed expression of SAMD14 together with hypermethylation at the promoter region, although an immortalized bronchial epithelium cell line (PL16B) did not show hypermethylation and did express SAMD14. The expression of SAMD14 in A549 was rescued by treatment with the demethylation agent 5‐aza‐2′‐deoxycytidine. These data indicate that hypermethylation of the SAMD14 gene promoter region is associated with silencing of its expression. Hypermethylation at the CpG site of the SAMD14 promoter region was detected frequently in early invasive adenocarcinoma (8/24, 33.3%) but not in in situ adenocarcinoma (0/7, 0%) or normal lung tissue (0/31, 0%). Hypermethylation of the SAMD14 gene is a specific event in pulmonary adenocarcinogenesis and malignant progression. (Cancer Sci 2008; 99: 2177–2184)
Constitutive heterologous expression of avrXa27 in rice containing the R gene Xa27 confers enhanced resistance to compatible Xanthomonas oryzae strains
Authors: TIAN DONGSHENG , YIN ZHONGCHAO
Published: September 2008

The vascular pathogen Xanthomonas oryzae pv. oryzae (Xoo) and nonvascular pathogen Xanthomonas oryzae pv. oryzicola (Xoc) cause bacterial blight (BB) and bacterial leaf streak (BLS) diseases of rice, respectively. We have previously identified the avirulence gene avrXa27 from Xoo PXO99A, which specifically induces the expression of the rice resistance gene Xa27, ultimately leading to resistance against BB disease in rice. In this study, we have generated a transgenic rice line (L24) that expresses avrXa27 constitutively under the control of the PR1 promoter, and have examined its role in the host–pathogen interaction. L24 is not more susceptible to BB, indicating that avrXa27 does not contribute to virulence. AvrXa27 retains avirulence activity in L24 and, after crossing with a line containing Xa27, progeny display phenotypic changes including inhibition of tillering, delay in flowering, stiff leaves, early leaf senescence and activation of pathogenesis‐related (PR) genes. On challenge with a variety of compatible strains of Xoo and Xoc strain L8, lines with both avrXa27 and Xa27 also show enhanced resistance to bacterial infection. The induction of Xa27 and subsequent inhibition of Xoc growth in Xa27 plants are observed on inoculation with Xoc L8 harbouring avrXa27. Our results indicate that the heterologous expression of avrXa27 in rice containing Xa27 triggers R gene‐specific resistance and, at the same time, confers enhanced resistance to compatible strains of Xoo and Xoc. The expression of AvrXa27 and related proteins in plants has the potential to generate broad resistance in plants.
The effects of polymorphisms in the DGAT1, leptin and growth hormone receptor gene loci on body energy, blood metabolic and reproductive traits of Holstein cows
Authors: Oikonomou G. , Angelopoulou K. , Arsenos G. , Zygoyiannis D. , Banos G.
Published: September 2008

The objective of this study was to examine the impact of polymorphisms in the acyl‐CoA:diacylglycerol acyltransferase (DGAT1), leptin and growth hormone receptor genes on body energy (body condition score, total body energy content and cumulative effective energy balance) and blood metabolic traits (levels of β‐hydroxybutyrate, glucose and non‐esterified fatty acids), measured once before the first calving and then repeatedly throughout first lactation in 497 Holstein cows. The influence of the same polymorphisms on cow reproductive performance and health during the first and second lactations was also assessed. Several reproductive traits were considered including interval, conception and insemination traits, as well as incidence of metritis and reproductive problems. Genotyping was performed using PCR‐RFLP (DGAT1, leptin) or allele‐specific PCR (growth hormone receptor). For each locus, the effect of allele substitution on body energy and blood metabolic traits was estimated using random regression models. The same effect on reproductive traits was assessed with single‐trait mixed linear models. Significant (P < 0.05) effects on specific reproductive traits were observed. DGAT1 and growth hormone receptor alleles responsible for significant increases in milk production were found to have an adverse effect on reproduction, while the leptin allele responsible for significant increase in milk production was linked to marginally increased metritis frequency. Furthermore, the three studied loci were also found to significantly (P < 0.05) affect certain body energy and blood metabolic traits. Several associations are published for the first time, but these should be confirmed by other investigators before the polymorphisms are used in gene‐assisted selection.
Relationship between body size and homing ability in the genus Osmia (Hymenoptera; Megachilidae)
Authors: GUÉDOT CHRISTELLE , BOSCH JORDI , KEMP WILLIAM P.
Published: September 2008

Abstract 1. The maximum homing ability of female bees, that is, their capacity to return to the nest after being displaced a certain distance, is considered to be an estimate of their maximum foraging distance.

2. The present study provides data on homing ability and body weight for Osmia lignaria and combines them with data for five other congenerics, O. rufa, O. cornuta, O. pedicornis, O. cornifrons, and O. emarginata for analysis. These species are important pollinators of spring‐flowering plants, and some have been developed as commercial crop pollinators.

3. It is shown that homing ability is positively and linearly related to body weight (r2 = 0.81; P = 0.01).

4. These results should be of use in selecting Osmia species as potential crop pollinators and establishing adequate buffer distances around genetically modified crops.
Wounding‐mediated gene expression and accelerated viviparous reproduction of the pea aphid Acyrthosiphon pisum
Authors: Altincicek B. , Gross J. , Vilcinskas A.
Published: September 2008

Most insects mount a potent antimicrobial defence upon contact with microbes or microbe‐associated pattern molecules. Using a combined set of methods for analysis of insect innate immunity, we report here that piercing of the pea aphid Acyrthosiphon pisum with a bacteria‐contaminated needle elicits lysozyme‐like activity in the haemolymph but no detectable activities against live bacteria. Confirming these results, we found no homologues of known antimicrobial peptides in our cDNA library generated by using the suppression subtractive hybridization method or in over 90 000 public expressed sequence tag (EST) sequences, but lysozyme genes have recently been described in A. pisum. Interestingly, we discovered that production of viviparous offspring was significantly accelerated upon wounding. Therefore, we postulate that aphids may increase terminal reproductive investment and limit antibacterial defence in response to a threat to their survival.
Exploring the Afromontane centre of endemism: Kniphofia Moench (Asphodelaceae) as a floristic indicator
Authors: Ramdhani Syd , Barker Nigel P. , Baijnath Himansu
Published: September 2008

Aim  The genus Kniphofia contains 71 species with an African–Malagasy distribution, including one species from Yemen. The genus has a general Afromontane distribution. Here we explore whether Kniphofia is a floristic indicator of the Afromontane centre of endemism and diversity. The South Africa Centre of diversity and endemism was explored in greater detail to understand biogeographical patterns.

Location  Africa, Afromontane Region, southern Africa, Madagascar and Yemen.

Methods  Diversity and endemism for the genus were examined at the continental scale using a chorological approach. Biogeographical patterns and endemism in the South Africa Centre were examined in greater detail using chorology, phenetics, parsimony analysis of endemicity (PAE) and mapping of range‐restricted taxa.

Results  Six centres of diversity were recovered, five of which are also centres of endemism. Eight subcentres of diversity are proposed, of which only two are considered subcentres of endemism. The South Africa Centre is the most species‐rich region and the largest centre of endemism for Kniphofia. The phenetic analysis of the South Africa Centre at the full degree square scale recovered three biogeographical areas that correspond with the subcentres obtained from the chorological analysis. The PAE (at the full degree square scale) and the mapping of range‐restricted taxa recovered two and six areas of endemism (AOEs), respectively. These latter two approaches produced results of limited value, possibly as a result of inadequate collecting of Kniphofia species. Only two AOEs were identified by PAE and these are embedded within two of the six AOEs recovered by the mapping of range‐restricted taxa. All the above AOEs are within the three subcentres found by chorological and phenetic analysis (at the full degree square scale) for the South Africa Centre.

Main conclusions  The centres for Kniphofia broadly correspond to the Afromontane regional mountain systems, but with some notable differences. We regard Kniphofia as a floristic indicator of the Afromontane Region sensu lato. In southern Africa, the phenetic approach at the full‐degree scale retrieved areas that correlate well with those obtained by the chorological approach.
Panmixia: an example from Dawson's burrowing bee (Amegilla dawsoni) (Hymenoptera: Anthophorini)
Authors: BEVERIDGE MAXINE , SIMMONS LEIGH W.
Published: September 2008

Dawson's burrowing bee is a large, fast‐flying solitary nesting bee endemic to the arid zone of Western Australia. In this study the population structure of the species was examined with molecular markers. Using eight microsatellite loci, we genotyped 531 adult female bees collected from 13 populations of Dawson's burrowing bee, Amegilla dawsoni, across the species range. The mean number of alleles per locus ranged from 4 to 38 and expected heterozygosity was uniformly high with a mean of 0.602. Pairwise comparisons of FST among all 13 populations ranged from 0.0071 to 0.0122 with only one significant estimate and an overall FST of 0.001. The entire sample collection was in Hardy–Weinberg equilibrium and there was no evidence of inbreeding with a mean FIS of 0.010. The mating and nesting behaviour of this bee suggests that gene flow would be limited by monandry and the fact that almost 90% of females mate immediately on emergence. Nevertheless there is obviously sufficient gene flow to maintain panmixia, and we suggest that this results from infrequent and unreliable rainfall in the species range, which causes the bees to congregate at limited food resources, allowing a small number of unmated females from one emergence site to come into contact with males from another population. In addition, when drought eliminates food resources near an emergence site, the whole population may move elsewhere, increasing gene flow across the species range.
Genetic variation in MHC class II expression and interactions with MHC sequence polymorphism in three‐spined sticklebacks
Authors: WEGNER K. M. , KALBE M. , RAUCH G. , KURTZ J. , SCHASCHL H. , REUSCH T. B. H.
Published: September 2008

Genes of the major histocompatibility complex (MHC) have been studied for several decades because of their pronounced allelic polymorphism. Structural allelic polymorphism is, however, not the only source of variability subjected to natural selection. Genetic variation may also exist in gene expression patterns. Here, we show that in a natural population of three‐spined sticklebacks (Gasterosteus aculeatus) the expression of MHC class IIB genes was positively correlated with parasite load, which indicates increased immune activation of the MHC when infections are frequent. To experimentally study MHC expression, we used laboratory‐bred sticklebacks that were exposed to three naturally occurring species of parasite. We found strong differences in MHC class IIB expression patterns among fish families, which were consistent over two generations, thus demonstrating a genetic component. The average number of MHC class IIB sequence variants within families was negatively correlated to the MHC expression level suggesting compensatory up‐regulation in fish with a low (i.e. suboptimal) MHC sequence variability. The observed differences among families and the negative correlation with individual sequence diversity imply that MHC expression is evolutionary relevant for the onset and control of the immune response in natural populations.
Pleistocene evolutionary history of the Clouded Apollo (Parnassius mnemosyne): genetic signatures of climate cycles and a ‘time‐dependent’ mitochondrial substitution rate
Authors: GRATTON P. , KONOPIŃSKI M. K. , SBORDONI V.
Published: September 2008

Genetic data are currently providing a large amount of new information on past distribution of species and are contributing to a new vision of Pleistocene ice ages. Nonetheless, an increasing number of studies on the ‘time dependency’ of mutation rates suggest that date assessments for evolutionary events of the Pleistocene might be overestimated. We analysed mitochondrial (mt) DNA (COI) sequence variation in 225 Parnassius mnemosyne individuals sampled across central and eastern Europe in order to assess (i) the existence of genetic signatures of Pleistocene climate shifts; and (ii) the timescale of demographic and evolutionary events. Our analyses reveal a phylogeographical pattern markedly influenced by the Pleistocene/Holocene climate shifts. Eastern Alpine and Balkan populations display comparatively high mtDNA diversity, suggesting multiple glacial refugia. On the other hand, three widely distributed and spatially segregated lineages occupy most of northern and eastern Europe, indicating postglacial recolonization from different refugial areas. We show that a conventional ‘phylogenetic’ substitution rate cannot account for the present distribution of genetic variation in this species, and we combine phylogeographical pattern and palaeoecological information in order to determine a suitable intraspecific rate through a Bayesian coalescent approach. We argue that our calibrated ‘time‐dependent’ rate (0.096 substitutions/million years), offers the most convincing time frame for the evolutionary events inferred from sequence data. When scaled by the new rate, estimates of divergence between Balkan and Alpine lineages point to c. 19 000 years before present (last glacial maximum), and parameters of demographic expansion for northern lineages are consistent with postglacial warming (5–11 000 years before present).
Tryptophan catabolism in females with irritable bowel syndrome: relationship to interferon‐gamma, severity of symptoms and psychiatric co‐morbidity
Authors: Fitzgerald P. , Cassidy Eugene M. , Clarke G. , Scully P. , Barry S. , Quigley Eamonn M. M. , Shanahan F. , Cryan J. , Dinan Timothy G.
Published: September 2008

Abstract Irritable bowel syndrome (IBS) has been linked with abnormal serotonin functioning and immune activation. Tryptophan forms the substrate for serotonin biosynthesis, but it can alternatively be catabolized to kynurenine (Kyn) by the enzyme indoleamine 2,3‐dioxygenase (IDO), the main inducer of which is interferon‐gamma. The primary aim of this study was to test the hypothesis that IBS is associated with increased tryptophan (Trp) catabolism along the Kyn pathway due to increased IFN‐γ levels. Plasma Kyn, Trp and IFN‐γ levels were measured in 41 female IBS subjects and 33 controls. Indoleamine 2,3‐dioxygenase activity was assessed using the Kyn to Trp ratio. Psychiatric co‐morbidity was assessed using the Patient Health Questionnaire, and severity of IBS assessed using self‐report ordinal scales. Irritable bowel syndrome subjects had increased Kyn concentrations compared with controls (P = 0.039) and there was a trend for Kyn:Trp to be increased in the IBS group (P = 0.09). There was a positive correlation between IBS severity and Kyn:Trp (r = 0.57,P < 0.001). Those with severe IBS symptoms had increased Kyn:Trp (P < 0.005) compared to those with less severe symptoms and controls, and were over twice as likely to have depression or anxiety compared to those with less severe IBS (RR = 2.2, 95% CI 1.2–3.9). No difference in IFN‐γ levels was observed between groups; however, IFN‐γ was positively correlated with Kyn:Trp in IBS (r = 0.58,P = 0.005) but not controls (r = 0.12,P = 0.5). Females with IBS have abnormal Trp catabolism. The Kyn:Trp is related to symptom severity, and those with severe IBS symptoms have increased shunting of Trp along the Kyn pathway which contributes to the abnormal serotonergic functioning in this syndrome.
Protein‐energy malnutrition decreases immune response to Leishmania chagasi vaccine in BALB/c mice
Authors: MALAFAIA G. , SERAFIM T. D. , SILVA M. E. , PEDROSA M. L. , REZENDE S. A.
Published: September 2008

Protein‐energy malnutrition and visceral leishmaniasis are important problems of public health affecting millions of people worldwide. Vaccine efficacy depends on the ability of individuals to mount an appropriate immune response and may be inadequate in malnourished persons. In this study, we used a mouse model to verify the effect of combined protein, iron and zinc deficiency in the response to Leishmania chagasi antigen vaccine. BALB/c mice were fed with a low‐protein (3% casein), iron‐ and zinc‐deficient diet or control diet (14% casein and sufficient in zinc and iron). After malnutrition establishment, mice were vaccinated subcutaneously with L. chagasi Ag plus saponin. After vaccination, mice were nutritionally repleted and then all mice were challenged with L. chagasi promastigotes. Four weeks later, liver and spleen parasite load was evaluated. Our data show that vaccine caused a significant reduction in parasite load in spleen and liver from mice fed with control diet. However, splenic parasitism was increased in mice fed with deficient diet and this diet caused a reduction in splenocyte IFN‐γ production in response to the vaccine in repleted mice. These data suggest that malnutrition may alter immune response to L. chagasi vaccine in BALB/c model of infection, even after nutritional repletion.
Successful allogeneic unrelated bone marrow transplantation using reduced‐intensity conditioning for the treatment of X‐linked adrenoleukodystrophy in a one‐yr‐old boy
Authors: Okamura Kazumi , Watanabe Tsutomu , Onishi Toshihiro , Watanabe Hiroyoshi , Fujii Emiko , Mori Kenji , Matsuda Junko
Published: September 2008

Abstract:  The childhood cerebral form of X‐linked ALD is a demyelinating disorder of the central nervous system, which rapidly leads to total disability and death. Allogeneic stem cell transplantation benefits patients who show early evidence of the demyelination. We report here a one‐yr‐old boy with ALD who received HLA‐matched unrelated BMT in an early stage of the disease after careful planning and observation since his birth. BMT was performed when MRI began to show slight signal intensity changes in the white matter of the brain. Pretransplant conditioning consisted of fludarabine, l‐PAM and TBI (2 Gy). GVHD prophylaxis consisted of cyclosporine A and short‐course methotrexate. The patient showed an uneventful BMT course with fast and stable engraftment. Following BMT, the plasma levels of VLCFA decreased gradually and MRI changes improved. The patient did not have any evidence of further neurological deterioration 22 months following the transplant. Although this is still a short follow‐up, it has been shown that BMT should be considered when a child has a biochemical diagnosis and MRI findings of ALD without any neurological signs. RIST should be considered as a pretransplant conditioning for ALD.