Adult Hindgut Research Articles

Determination of the larval precursor configuration of the Drosophila adult hindgut by G-TRACE analysis

The Drosophila hindgut is a classical model to study organogenesis. The adult hindgut originates from the precursor cells in the larval hindgut. However, the territory of these cells has still not been well determined. A ring of wingless (wg)-expressing cells lies at the anterior zone of both the larval and adult hindgut. The larval Wg ring was thought as a portion of precursor of the adult hindgut. By applying a cell lineage tracing tool (G-TRACE), we demonstrate that larval wg-expressing cells have no cell lineage contribution to the adult hindgut. Additionally, adult Wg ring cells do not divide and move posteriorly to replenish the hindgut tissue. Instead, we determine that the precursors of the adult pylorus and ileum are situated in the cubitus interruptus (ci)-expressing cells in the anterior zone, and deduce that the precursor stem cells of the adult rectum locate in the trunk region of the larval pylorus including hedgehog (hh)-expressing cells. Together, this research advances our understanding of cell lineage origins and the development of the Drosophila hindgut.

The homeodomain transcription factor Orthopedia is involved in development of the Drosophila hindgut

BackgroundThe Drosophila hindgut is commonly used model for studying various aspects of organogenesis like primordium establishment, further specification, patterning, and morphogenesis. During embryonic development of Drosophila, many transcriptional activators are involved in the formation of the hindgut. The transcription factor Orthopedia (Otp), a member of the 57B homeobox gene cluster, is expressed in the hindgut and nervous system of developing Drosophila embryos, but due to the lack of mutants no functional analysis has been conducted yet.ResultsWe show that two different otp transcripts, a hindgut-specific and a nervous system-specific form, are present in the Drosophila embryo. Using an Otp antibody, a detailed expression analysis during hindgut development was carried out. Otp was not only expressed in the embryonic hindgut, but also in the larval and adult hindgut. To analyse the function of otp, we generated the mutant otp allele otpGT by ends-out gene targeting. In addition, we isolated two EMS-induced otp alleles in a genetic screen for mutants of the 57B region. All three otp alleles showed embryonic lethality with a severe hindgut phenotype. Anal pads were reduced and the large intestine was completely missing. This phenotype is due to apoptosis in the hindgut primordium and the developing hindgut.ConclusionOur data suggest that Otp is another important factor for hindgut development of Drosophila. As a downstream factor of byn Otp is most likely present only in differentiated hindgut cells during all stages of development rather than in stem cells.

脐腹小蠹聚集信息素的提取鉴定和引诱效果

PDF HTML阅读 XML下载 导出引用 引用提醒 脐腹小蠹聚集信息素的提取鉴定和引诱效果 DOI: 10.5846/stxb201311032656 作者: 作者单位: 山西农业大学文理学院化学生态研究所,宁夏哈巴湖国家级自然保护区管理局高沙窝管理站,山西农业大学文理学院化学生态研究所,山西农业大学文理学院化学生态研究所,山西农业大学文理学院化学生态研究所,北京林业大学省部建森林培育与保护教育部重点实验室 作者简介: 通讯作者: 中图分类号: 基金项目: 国家"十二五"科技支撑项目(2012BAD19B0701); 山西农业大学科技创新基金项目(201227); 山西农业大学博士科研启动项目(XB2011006) Extraction and identification of aggregation pheromone components of Scolytus schevyrewi Semenov(Coleoptera: Scolytidae) and trapping test Author: Affiliation: Institute of Chemical Ecology of Art and Science College, Shanxi Agriculture University,,,,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为了确定脐腹小蠹Scolytus schevyrewi Semenov的聚集信息素成分,对脐腹小蠹成虫后肠和虫粪的挥发物进行了提取鉴定和引诱试验。经气相色谱-质谱联用仪(GC-MS)鉴定,结果表明:雌成虫后肠挥发物成分有十四烷、十五烷、十六烷、十八烷、十九烷、十二酸和十四酸,其中十四酸含量最高,达到了42.2%;雄成虫后肠挥发物成分有十一烷、十四烷、十五烷、十六烷、十八烷和十九烷,十六烷(23.3%)和十九烷(21.5%)含量最多;雌成虫虫粪挥发物成分有十一烷、十二烷、十四烷、十六烷、十八烷和十九烷,十九烷含量最高,为29.9%;雄成虫虫粪挥发物成分有庚烷、十一烷、十二烷、十四烷、十六烷、十八烷、二十二烷和二十三烷,庚烷(20.5%)相对含量最多。此外,借助触角电位仪测定了脐腹小蠹雌雄虫触角对这些单一物质刺激的反应,结果显示,触角电位相对值较大的为十二酸、十四酸和十八烷。雌雄间比较发现十二酸、十四酸和十九烷刺激后雌雄间触角电位相对值差异达到了显著水平(P < 0.05)。田间诱捕结果显示,十二酸、十四酸、十九烷对脐腹小蠹的引诱数量雌雄间差异性达到了显著水平(P < 0.05),成虫诱捕总量最多的是十八烷,诱捕量达32.1 头,其后诱捕量较多的为十二酸(24.1 头)和十四酸(22.7 头)。可以推断,十八烷、十九烷、十二酸和十四酸是脐腹小蠹聚集信息素的主要成分。 Abstract:The banded elm bark beetle (BEBB), Scolytus schevyrewi Semenov (Coleoptera: Scolytidae), is a pest of Ulmus pumila L. This pest, which was first reported in Asia, carries spores of tmhe fungal pathogen that causes Dutch elm disease. In recent years, an extensive elm forest in Yanchi County, Ningxia Province, was severely damaged by the BEBB, resulting in large-scale destruction and death of trees. At least 98% of the mortalities occurred in forestry stations, with the extent of damage similar to that produced by a raging fire. The staff of local bureaus of environmental protection and forestry bureaus implemented various measures to revive these forests; however, their efforts yielded little success. Foreign countries have installed traps to preserve their forests from further destruction due to BEBB infestation. For example, these pests were collected in Colorado, USA, using traps containing attractants for woodborers (i.e., α-pinene and ethanol) as bait, whereas those in Utah were gathered in traps baited with ethanol or the 3 components of the aggregation pheromone of the Eurasian spruce engraver, Ips typographus L. (Coleoptera: Scolytidae). Chemical communication in bark beetles using aggregation pheromones plays a key role in mate location and in harming host plants. However, the components of the aggregation pheromone of the BEBB remain unidentified. To screen the chemicals of the BEBB aggregation pheromone, the volatiles in male and female adult hindguts and feces were analyzed by gas chromatography-mass spectrometry in the laboratory and in the elm forest fields in Yanchi County. The volatiles of male adult hindguts mainly contained seven components-tetradecane, pentadecane, hexadecane, octadecane, nonadecane, dodecanoic acid, and myristic acid of which myristic acid was predominant (42.2%). The volatiles of the female adult hindgut consisted of six ingredients-undecane, tetradecane, pentadecane, hexadecane, octadecane, and nonadecane of which hexadecane (23.3%) and nonadecane (21.5%) were the predominant types. Volatiles in male feces consisted of six components-undecane, dodecane, tetradecane, hexadecane, octadecane, and nonadecane-of which nonadecane was predominant (29.9%), whereas those in female feces contained eight chemicals-heptanes, undecane, dodecane, tetradecane, hexadecane, octadecane, docosane, and tricosane of which the alkanes accounted for 20.5%. In addition, the responses of adult antennae to 10 μL of individual volatiles at a concentration of 10 μg/μL were measured using an electroantennogram (EAG) detector. Among the various substances examined, dodecanoic acid, myristic acid, and octadecane showed the strongest response. By comparing the EAG values of the substances in the antennae in females with those in males, dodecanoic acid, myristic acid, and nonadecane reached significant levels (P < 0.05) in terms of responses. Both adult males and female BEBB were collected in the field using cross-shaped traps containing chemoattractants from June 25th to July 4th in 2010. There was a significant difference (P < 0.05) between the number of male and female BEBBs captured using dodecanoic acid, myristic acid, and nonadecane. In terms of the trapping effect, octadecane was most effective, resulting in 32.1 adults trapped, followed by dodecanoic acid (24.1 adults), and myristic acid (22.7 adults). Therefore, octadecane, nonadecane, dodecanoic acid, and myristic acid are the most probable main components of the BEBB aggregation pheromone. 参考文献 相似文献 引证文献

Draft genome sequences of two Bifidobacterium sp. from the honey bee (Apis mellifera)

BackgroundWidely considered probiotic organisms, Bifidobacteria are common inhabitants of the alimentary tract of animals including insects. Bifidobacteria identified from the honey bee are found in larval guts and throughout the alimentary tract, but attain their greatest abundance in the adult hind gut. To further understand the role of Bifidobacteria in honey bees, we sequenced two strains of Bifidobacterium cultured from different alimentary tract environments and life stages.ResultsReflecting an oxygen-rich niche, both strains possessed catalase, peroxidase, superoxide-dismutase and respiratory chain enzymes indicative of oxidative metabolism. The strains show markedly different carbohydrate processing capabilities, with one possessing auxiliary and key enzymes of the Entner-Doudoroff pathway.ConclusionsAs a result of long term co-evolution, honey bee associated Bifidobacterium may harbor considerable strain diversity reflecting adaptation to a variety of different honey bee microenvironments and hive-mediated vertical transmission between generations.

The Drosophila Hindgut Lacks Constitutively Active Adult Stem Cells but Proliferates in Response to Tissue Damage

The adult Drosophila hindgut was recently reported to contain active, tissue-replenishing stem cells, like those of the midgut, but located within an anterior ring so as to comprise a single giant crypt. In contrast to this view, we observed no active stem cells and little cell turnover in adult hindgut tissue based on clonal marking and BrdU incorporation studies. Again contradicting the previous proposal, we showed that the adult hindgut is not generated by anterior stem cells during larval/pupal development. However, severe tissue damage within the hindgut elicits cell proliferation within a ring of putative quiescent stem cells at the anterior of the pylorus. Thus, the hindgut does not provide a model of tissue maintenance by constitutively active stem cells, but has great potential to illuminate mechanisms of stress-induced tissue repair.

The larval alimentary canal of the Antarctic insect, Belgica antarctica

On the Antarctica continent the wingless midge, Belgica antarctica (Diptera, Chironomidae) occurs further south than any other insect. The digestive tract of the larval stage of Belgica that inhabits this extreme environment and feeds in detritus of penguin rookeries has been described for the first time. Ingested food passes through a foregut lumen and into a stomodeal valve representing an intussusception of the foregut into the midgut. A sharp discontinuity in microvillar length occurs at an interface separating relatively long microvilli of the stomodeal midgut region, the site where peritrophic membrane originates, from the midgut epithelium lying posterior to this stomodeal region. Although shapes of cells along the length of this non-stomodeal midgut epithelium are similar, the lengths of their microvilli increase over two orders of magnitude from anterior midgut to posterior midgut. Infoldings of the basal membranes also account for a greatly expanded interface between midgut cells and the hemocoel. The epithelial cells of the hindgut seem to be specialized for exchange of water with their environment, with the anterior two-thirds of the hindgut showing highly convoluted luminal membranes and the posterior third having a highly convoluted basal surface. The lumen of the middle third of the hindgut has a dense population of resident bacteria. Regenerative cells are scattered throughout the larval midgut epithelium. These presumably represent stem cells for the adult midgut, while a ring of cells, marked by a discontinuity in nuclear size at the midgut-hindgut interface, presumably represents stem cells for the adult hindgut.

Big brain, a Drosophila homologue of mammalian aquaporin, is regulated by the DRE/DREF system

Drosophila big brain (bib) encodes for a protein similar to members of the major intrinsic protein family, which includes the water- and ion-conducting aquaporin (AQP) channels. In mammals, AQP dysregulation has been implicated in a variety of diseases, including colorectal cancer and colonic injury. However, the regulatory mechanisms of AQP expression remain to be clearly elucidated. In this study, as we found a DREF binding site (DRE) in the 5'-flanking regions of both the Drosophila bib gene and the human AQP1 gene, we assessed the role of DREF in bib gene expression. DREF in Drosophila and humans has been demonstrated to function as a key transcriptional activator for cell proliferation-related genes. Herein, we demonstrate that the DRE is required for optimal promoter activity of Drosophila bib gene, particularly in the larval imaginal discs, which are actively proliferating tissues, as well as the adult hindgut. Our results may provide insight into the mechanisms inherent to the regulation of mammalian AQP genes.

The behaviour of Drosophila adult hindgut stem cells is controlled by Wnt and Hh signalling

The intestinal tract maintains proper function by replacing aged cells with freshly produced cells that arise from a population of self-renewing intestinal stem cells (ISCs). In the mammalian intestine, ISC self renewal, amplification and differentiation take place along the crypt-villus axis, and are controlled by the Wnt and hedgehog (Hh) signalling pathways. However, little is known about the mechanisms that specify ISCs within the developing intestinal epithelium, or about the signalling centres that help maintain them in their self-renewing stem cell state. Here we show that in adult Drosophila melanogaster, ISCs of the posterior intestine (hindgut) are confined to an anterior narrow segment, which we name the hindgut proliferation zone (HPZ). Within the HPZ, self renewal of ISCs, as well as subsequent proliferation and differentiation of ISC descendants, are controlled by locally emanating Wingless (Wg, a Drosophila Wnt homologue) and Hh signals. The anteriorly restricted expression of Wg in the HPZ acts as a niche signal that maintains cells in a slow-cycling, self-renewing mode. As cells divide and move posteriorly away from the Wg source, they enter a phase of rapid proliferation. During this phase, Hh signal is required for exiting the cell cycle and the onset of differentiation. The HPZ, with its characteristic proliferation dynamics and signalling properties, is set up during the embryonic phase and becomes active in the larva, where it generates all adult hindgut cells including ISCs. The mechanism and genetic control of cell renewal in the Drosophila HPZ exhibits a large degree of similarity with what is seen in the mammalian intestine. Our analysis of the Drosophila HPZ provides an insight into the specification and control of stem cells, highlighting the way in which the spatial pattern of signals that promote self renewal, growth and differentiation is set up within a genetically tractable model system.

P-type Na+/K+-ATPase and V-type H+-ATPase expression patterns in the osmoregulatory organs of larval and adult mosquitoAedes aegypti

This study describes the expression patterns of P-type Na(+)/K(+)-ATPase and V-type H(+)-ATPase in the larval and adult forms of the mosquito Aedes aegypti and provides insight into their relative importance in ion transport function of key osmoregulatory organs. RT-PCR assays indicate that, at the level of the gene, both ATPases are expressed in all of the osmoregulatory tissues of larvae (midgut, Malpighian tubules, rectum and anal papillae) and adults (stomach, Malpighian tubules, anterior hindgut and rectum). Immunohistochemical studies determined that both ATPases are present in high levels in all the relevant organs, with the exception of the larval rectum (P-type Na(+)/K(+)-ATPase only). In larval gastric caeca, ATPase location corresponds to the secretory (basal P-type Na(+)/K(+)-ATPase, apical V-type H(+)-ATPase) and ion-transporting (V-type H(+)-ATPase on both membranes) regions as previously described. The two ATPases switch membrane location along the length of the larval midgut, indicating three possible regionalizations, whereas the adult stomach has uniform expression of basolateral P-type Na(+)/K(+)-ATPase and apical V-type H(+)-ATPase in each cell. In both larval and adult Malpighian tubules, the distal principal cells exhibit high expression levels of V-type H(+)-ATPase (apically and cytoplasmically) whereas P-type Na(+)/K(+)-ATPase is highly expressed in stellate cells found only in the distal two-thirds of each tubule. By contrast, the proximal principal cells express both P-type Na(+)/K(+)-ATPase (basal) and V-type H(+)-ATPase (apical). These results suggest a functional segregation along the length of the Malpighian tubules based on cell type and region. P-type Na(+)/K(+)-ATPase is the only pump apparent in the larval rectum whereas in the larval anal papillae and the adult hindgut (including the anterior hindgut and rectum with rectal pads), P-type Na(+)/K(+)-ATPase and V-type H(+)-ATPase localize to the basal and apical membranes, respectively. We discuss our findings in light of previous physiological and morphological studies and re-examine our current models of ion transport in these two developmental stages of mosquitoes that cope with disparate osmoregulatory challenges.

Effect of dietary fiber concentration on apparent digestibility and digesta passage in non-human primates. II. Hindgut- and foregut-fermenting folivores

Two test diets with different acid detergent fiber (ADF) concentrations (15% ADF, 30% ADF) were fed to seven adult hindgut- and seven adult foregut-fermenting primates. Apparent digestibilities (%) of dietary dry matter (DM), gross energy (GE), and fiber components (neutral detergent fiber [NDF], ADF, hemicellulose [HC], and cellulose [C]) were measured. Rates of digesta transit (TT1) and retention (RGIT) times were assessed using acetate beads, Co-ethylenediaminetetraacetic acid, and Cr-mordanted fiber as markers. Apparent digestibilities (%) of components of the 15ADF and 30ADF diets, respectively, by hindgut versus foregut fermenters were 69.3 and 61.7 versus 81.2 and 76.7 for DM, 68.5 and 61.5 versus 80.9 and 75.6 for GE, and 44.8 and 47.4 versus 77.1 and 74.7 for NDF. No significant differences in TT1 or RGIT between dietary treatments or markers were detected. The role of plant fiber in maintaining the health and normal function of the gastrointestinal tract in captive leaf-eating primates is discussed. Zoo Biol 18:537–549, 1999. © 1999 Wiley-Liss, Inc.

Sex‐specific neuronal respecification during the metamorphosis of the genital segments of the tobacco hornworm moth Manduca sexta

At metamorphosis, the terminal abdominal segments of larvae of the moth Manduca sexta transform into either male or female genitalia. At the start of this transformation, the larval muscles degenerate but their remains may persist to form the scaffolding on which the new adult muscles differentiate. The survival and subsequent orientation of larval muscle remnants is determined by the sex of the individual and is independent of motor innervation at the start of metamorphosis. Many of the larval motoneurons persist through metamorphosis and innervate the skeletal muscle of the adult. The survival of particular motoneurons is also sex-dependent and correlated with the survival of its respective muscle remnant. No new skeletal motoneurons arise postembryonically, so all of the adult skeletal muscle motoneurons are derived from preexisting larval skeletal muscle motoneurons. The fates during metamorphosis are more complex for the visceral muscle motoneurons. Those innervating the adult hindgut of both sexes are identical and are derived from the larval hindgut motoneurons. Other hindgut motoneurons in the larva switch targets during metamorphosis and come to innervate the oviduct in adult females or perish in adult males. Other regions of the reproductive tract become innervated by adult-specific cells that differentiate during metamorphosis. These cells come from distinct lineages in males and females.

Cuticular control of diffusional water permeability

The diffusional water permeability ( P d ) in various gut structures of the fleshfly, Sarcophaga bullata, was measured using tritiated water. Water P d in the larval hindgut was 3.91 × 10 −6 cm/sec, whereas in the adult hindgut it was 4.4 × 10 −4 cm/sec. The presence of cuticle in various parts of the gut apparently controls the water permeabilities of these structures. Furthermore, the water permeability of the cuticle may be correlated with the mechanism for the production of a hyperosmotic excretion in the hindgut.

Patterns of alkaline phosphatase in developing Drosophila.

Electrophoretic study of alkaline phosphatase in developing Drosophila shows that different stages are characterized by the appearance and disappearance of organ-specific enzyme bands. A new electrophoretic variant, from adult hindgut, is controlled by the second chromosome locus Aph-2.