Immunohistochemical investigation of locust neuroparsin-like substances in several insects, in some other invertebrates, and vertebrates

Anti-neuroparsin serum was immunohistochemically tested on brain and/or neurohemal organ from 40 insect species belonging to 13 orders, and from 8 non-insect invertebrate and 5 vertebrate representatives using the peroxidase-antiperoxidase procedure. In insects, immunostaining of only the A1 type of the protocerebral median neurosecretory cells was revealed in all species tested of Odonata, Dictyoptera, Isoptera and Orthoptera and in 2 species from the 9 other orders out of 13 orders tested. No immunostaining was detected in vertebrate and non-insect invertebrate species except in 2 annelid species out of 4 tested. The distribution of neuroparsin-like products in Coelomata appears to be restricted mainly to 4 phylogenetically close insect orders.     

Identification of a pentanucleotide telomeric sequence, (TTAGG)n, in the silkworm Bombyx mori and in other insects.

A pentanucleotide repetitive sequence, (TTAGG)n, has been isolated from a silkworm genomic library, using cross-hybridization with a (TTNGGG)5 sequence, which is conserved among most eukaryotic telomeres. Both fluorescent in situ hybridization and Bal 31 exonuclease experiments revealed major clusters of (TTAGG)n at the telomeres of all Bombyx chromosomes. To determine the evolutionary origin of this sequence, two types of telomeric sequence, (TTAGG)5 and a hexanucleotide repetitive sequence, (TTAGGG)4, which is conserved mainly among vertebrate and several invertebrate telomeres so far examined, were hybridized to DNAs from a wide variety of eukaryotic species under highly stringent hybridization conditions. The (TTAGGG)5 oligonucleotide hybridized to genomic DNAs from vertebrates and several nonvertebrate species, as has been reported so far, but not to any DNAs from insects. On the other hand, the Bombyx type of telomere sequence, (TTAGG)n, hybridized to DNAs from 8 of 11 orders of insect species tested but not to vertebrate DNAs, suggesting that this TTAGG repetitive sequence is conserved widely among insects.     

Macroinvertebrate assemblage patterns as indicators of water quality in the Xindian watershed,Taiwan

In the present study, we assessed the water quality along a stretch of the watershed with considerable economic importance at the Xindian in Taiwan, using macroinvertebrate assemblages, along with environmental variables. The research was carried out at the seven sampling sites (abbreviated as XD1–XD7) where human impacts varied in intensity from upstream tributaries to the downstream of the Xindian watershed from December 2010 to December 2011. All variables except for the hardness, pH, dissolved oxygen, conductivity, turbidity, phosphate, ammonia, and alkalinity were significantly different (P < 0.05) between the sampling sites. A total of seventy seven taxa belonging to forty five families within eight insect orders, along with three non-insect invertebrate taxa were recorded, with most representative orders being Ephemeroptera and Diptera. Mean values of the density, abundance of macroinvertebrates, Shannon index, Simpson index, and Pielou's evenness were much higher in the reference sites, XD2, XD3, and XD4 compared with impacted sites, XD5, XD6, and XD7. Most of the benthic metrics were greatest in the reference site compared to the impacted site. Only the composition measures, percentages of Chironomidae and Oligochaeta which are more tolerant to pollution were dominant in the impacted site, XD7. As the results of assessment by different benthic metrics, water quality of Xindian watershed became gradually worse from upstream to downstream. Generally, our results suggest that macroinvertebrate assemblages can be used for assessment of water quality.     

The predators of insects

Abstract. 1. Insect–insectivore trophic relations were reviewed using presence–absence data from sixty-one invertebrate-dominated food webs and fifteen food webs from Briand's (1983) original forty web collection. From counts of prey links in higher taxa (orders, classes, phyla), six phyla and thirteen classes of non-insect insectivores and fourteen orders of insect predators and prey were found. 2. Detritus-based habitats (phytotelmata, felled logs, carcasses, dungpads) harboured fewer orders of insects, that interact with other insects, than webs from grazer-based (host plants, some galls) and mixed-based systems (aquatic webs). Consumer–resource networks of higher insect taxa in these webs shared several features found in some species-level biological networks: the trend was towards few pairs of strong asymmetrical links, several weak links and many null interactions. 3. From counts of insect predator–insect prey links, hymenopterans as terrestrial predators and parasitoids interacted with the most number of higher insect taxa. Hymenopterans were also linked as prey more often than other terrestrial insects. In freshwater habitats, plecopterans were linked as predators more often than other aquatic taxa, whereas dipterans were listed as prey more often than other insects. 4. Dipterans were linked in the diets of non-insect insectivores from seven of eight common taxonomic classes. Arachnids were identified as insect predators by food web researchers in the largest number of webs, followed by passerine birds and cyprinodont fishes. From analysis of prey links at the ordinal level, predaceous insects were less polyphagous than other predators (other ectotherms and endotherms). 5. Analysis of chain lengths, as expected, showed that insect prey occupied mostly lowermost trophic levels, non-insect insectivores were found mostly at uppermost trophic levels, and predaceous insects were found mostly at intermediate trophic levels across most habitats. 6. This analysis offers evidence that insects are not just occupying intermediate trophic levels in some communities. Indeed, some taxa feed at the upper ends of long food chains, for example eupelmids in galls, staphylinids in carcasses, and perlid plecopterans in streams.     

Eleven new putative aminergic G-protein coupled receptors from Amphioxus (<Emphasis Type="Italic">Branchiostoma floridae</Emphasis>): identification,sequence analysis and phylogenetic relationship

We have identified eleven novel aminergic-like G-protein coupled receptor (GPCRs) sequences (named AmphiAmR1-11) by searching the genomic trace sequence database for the amphioxus species, Branchiostoma floridae. They share many of the structural motifs that have been used to characterize vertebrate and invertebrate aminergic GPCRs. A preliminary classification of these receptors has been carried out using both BLAST and Hidden Markov Model analyses. The amphioxus genome appears to express a number of D1-like dopamine receptor sequences, including one related to insect dopamine receptors. It also expresses a number of receptors that resemble invertebrate octopamine/tyramine receptors and others that resemble vertebrate alpha-adrenergic receptors. Amphioxus also expresses receptors that resemble vertebrate histamine receptors. Several of the novel receptor sequences have been identified in amphioxus cDNA libraries from a number of tissues.     

Molecular cloning,expression pattern and phylogenetic analysis of myosin light chain 2 gene from Antheraea pernyi: A potential marker for phylogenetic inference

Myosin light chain 2 (MLC-2) gene was isolated and characterized from Antheraea pernyi, a well-known wild silkmoth. The isolated cDNA sequence is 905 bp in length with an open reading frame of 612 bp encoding a polypeptide of 203 amino acids. Semi-quantitative RT-PCR analysis showed that the MLC-2 gene was transcribed during four developmental stages (egg, larva, pupa, and moth), and present in all tissues tested. Alignment analysis revealed that the deduced protein sequence has over 95% identity to myosin light chain 2 of lepidopteran species, and 57–88% identity to other insect species, suggesting that insect MLC-2 proteins are highly conserved throughout evolution. The protein sequence was used to construct phylogenetic trees with other known vertebrate and invertebrate MLC-2 sequences, and the obtained trees demonstrated similar topology with the classical systematics, indicating the potential value of MLC-2 gene in phylogenetic study.     

Recolonisation of four small streams in central Scotland following drought conditions in 1984

Four streams in the Loch Ard Forest in central Scotland dried out almost completely during a drought in the summer of 1984. The recovery of the invertebrate populations in the streams was studied from September 1984 until March 1985 when most of the insect larvae and nymphs were almost full-grown.The appearance of very small larvae belonging to several insect orders within a month of the streams' filling up suggests that they had survived the drought as eggs, or eggs had been laid by adults soon after the drought ended.Statistical analysis showed that with the exception of 3 taxa there was no significant difference between the numbers of animals in November 1984 samples and in samples collected in March 1985.Comparison of samples from March 1984 and March 1985 showed significant difference in population size for a few species; with 2 exceptions the 1984 samples (ie before drought) were larger. In the long term the overall effect of the drought on the invertebrate communities seems to have been limited.     

The activities of pyruvate carboxylase, phosphoenolpyruvate carboxylase and fructose diphosphatase in muscles from vertebrates and invertebrates

1. The activities of pyruvate carboxylase, phosphoenolpyruvate carboxylase and fructose diphosphatase in crude homogenates of vertebrate and invertebrate muscles are reported. 2. Pyruvate carboxylase activity was present in all insect flight muscles that were investigated: in homogenates of bumble-bee flight muscle the activity was inhibited by ADP and activated by acetyl-CoA, and it was distributed mainly in the mitochondrial fraction. This is the first demonstration of pyruvate carboxylase activity in muscle. However, the activity appears to be restricted to insect flight muscle, since it was not found in other invertebrate or vertebrate muscles. 3. Since the three enzymes were never found together in the same muscle, it is concluded that these enzymes cannot provide a pathway for the synthesis of glycogen from lactate or pyruvate in muscle. Other roles for these enzymes in muscle are suggested. In particular, pyruvate carboxylase may be present in insect flight muscle for the provision of oxaloacetate to support the large increase in activity of the tricarboxylic acid cycle which occurs when an insect takes flight.     

Benthic macro- and meso-invertebrates of a sandy riverbed in a mountain stream, central Japan

Quantitative samples of benthic invertebrates were collected from a sandy riverbed of a mountainous stream (Kozu site of Takami-gawa stream, Nara Prefecture), central Japan by core samplers in five sampling occasions through the years 2008–2009. A total of 120 taxa were identified, representing 55 families and 97 genera. Insects formed about 92% of the total recorded taxa and 88% of individuals’ abundance. A total of 111 taxa of aquatic insects, belonging to 49 families and 92 genera, were identified and represented by ten orders. Oligochaeta and Acari were dominant non-insect invertebrates. Diptera was the most diverse insect group, followed by Trichoptera and Ephemeroptera. Dominant taxa were mesoinvertebrates, younger stages of macroinvertebrates, both of which predominantly inhabit the interstitial zone of a sandy riverbed. Both taxon richness and invertebrate abundance were higher in February 2009 and lower in April and August 2008. A few major invertebrate taxa demonstrated distinct seasonal trends; i.e. Nymphomyia alba, Rheosmittia, and Corynoneura were abundant in February 2009. Newly hatched larvae of Larcasia akagiae were abundant in May 2008. This study also demonstrated the effectiveness of core samplers to collect small-sized benthic fauna that inhabit the interstitial or hyporheic zone of the sandy riverbed.     

Reduced vertebrate diversity independent of spatial scale following feral swine invasions

Biological invasions often have contrasting consequences with reports of invasions decreasing diversity at small scales and facilitating diversity at large scales. Thus, previous literature has concluded that invasions have a fundamental spatial scale‐dependent relationship with diversity. Whether the scale‐dependent effects apply to vertebrate invaders is questionable because studies consistently report that vertebrate invasions produce different outcomes than plant or invertebrate invasions. Namely, vertebrate invasions generally have a larger effect size on species richness and vertebrate invaders commonly cause extinction, whereas extinctions are rare following invertebrate or plant invasions. In an agroecosystem invaded by a non‐native ungulate (i.e., feral swine, Sus scrofa), we monitored species richness of native vertebrates in forest fragments ranging across four orders of magnitude in area. We tested three predictions of the scale‐dependence hypothesis: (a) Vertebrate species richness would positively increase with area, (b) the species richness y‐intercept would be lower when invaded, and (c) the rate of native species accumulation with area would be steeper when invaded. Indeed, native vertebrate richness increased with area and the species richness was 26% lower than should be expected when the invasive ungulate was present. However, there was no evidence that the relationship was scale dependent. Our data indicate the scale‐dependent effect of biological invasions may not apply to vertebrate invasions.     

Contrasting effects of insect and molluscan herbivores on plant diversity in a long-term field experiment

The importance of invertebrate herbivores in regulating plant communities remains unclear, due to the absence of long-term exclusion experiments. An experiment in an English grassland involving long-term exclusions of insect and mollusc herbivores, along with rabbit fencing, showed strong, but opposing, effects of the invertebrate herbivores. Plant species richness declined and biomass increased following insect exclusion, due to increased dominance by a grass species, whereas mollusc exclusion led to increased herbs abundance. The two herbivores had a compensatory interaction: molluscs had no effects in the absence of insects and large insect effects depended on the absence of molluscs. The effects of invertebrate exclusion became apparent only after 8 years, and would have been seriously underestimated in shorter studies. Our results suggest that theorists and conservation managers need to shift from their historic focus on vertebrate herbivory, to a recognition that invertebrates can be equally important drivers of plant community structure.     

Distributions of Ephemeroptera, Plecoptera, and Trichoptera of three maritime catchments differing in pH

1. Two broad-scale environmental influences affecting species of Ephemeroptera, Trichoptera and Plecoptera inhabiting riffle habitat of three study catchments in New Brunswick and Nova Scotia were stream size-temperature-related variables and acidity-related variables. 2. Species richness was most affected by acidity in tributaries of intermediate size <0.001<0.1m³s^?1). 3. Of the three insect orders investigated, mayfly species richness was affected most by acidity, and stonefly species richness affected least by this factor. 4. Zoogeographical isolation of the Nova Scotian catchments resulted in absence of some species of low general abundance, but these species had little influence on the site classification by TWINSPAN analysis. 5. Predaceous stoneflies were collected in greater numbers from circumneutral sites and predaceous caddisflies in greater numbers from the Nova Scotian sites. 6. Although the Nova Scotian catchments have probably been historically acidic, due to high concentrations of organic acids, pH currently limits the distributions of many indigenous invertebrate species. These species may be vulnerable to the more recent, additional, anthropogenic acidification of these catchments.     

四川南充市春季麦田昆虫群落结构初步调查

通过巴氏罐诱法及网捕法、目测法,对南充市4月份的麦田昆虫群落进行分层调查,结果显示地表昆虫5目14科30种,其中天敌昆虫1目2科5种;麦田中上层昆虫7目10科21种,其中天敌昆虫4目5科16种。调查表明南充市麦田昆虫种类较多,天敌昆虫种类丰富,不同种类天敌昆虫占据不同的生态位,各自发挥作用,应保护利用。     

Insight into tachykinin-related peptides,their receptors,and invertebrate tachykinins: a review

Tachykinins (TKs) constitute the largest vertebrate neuropeptide family with multifunctions in central and peripheral tissues. In several invertebrate species, two types of structurally related peptides, 'tachykinin-related peptides (TKRPs)' and 'invertebrate tachykinins (inv-TKs)' have been identified. TKRPs, isolated from the nerve and/or gut tissues, contain the common C-terminal sequence -Phe-X-Gly-Y-Arg-NH(2) (X and Y are variable) analogous to the vertebrate TK consensus -Phe-X-Gly-Leu-Met-NH(2), and exhibit vertebrate TK-like contractile activity on invertebrate gut tissues. Inv-TKs have been shown to be present exclusively in the salivary gland of several species, to share vertebrate TK consensus motif, and to possess TK-like potencies on vertebrate, not invertebrate tissues. However, the functional and evolutionary relevance of TKRPs and inv-TKs to vertebrate TKs remains to be understood. Recent studies have revealed that TKRP precursors dramatically differ from vertebrate preprotachykinins in structural organization and that TKRP receptors share structural and functional properties with vertebrate TK receptors. Moreover, the C-terminal arginine in TKRPs has been shown to play an essential role in discriminating their receptors from vertebrate TK receptors. Such recent marked progress is expected to enhance further investigation of biological roles of TKRPs. This review provides an overview of the basic findings obtained previously and a buildup of new knowledge regarding TKRPs and inv-TKs. We also compare TKRPs and inv-TKs to vertebrate TKs with regard to evolutionary relationships in structure and function among these structurally related peptides.     

麦田昆虫群落的结构与时序动态

采用目测法和网捕法 ,通过对小麦整个生长季节内昆虫群落的系统调查 ,共查得昆虫11目 2 3科 36种 ,其中捕食性昆虫有 4目 5科 12种、寄生性昆虫有 2目 3科 4种、植食性昆虫有 5目 12科 15种、粪食性等其他类昆虫有 1目 3科 5种。在捕食性天敌昆虫中 ,瓢虫的种类和数量最多 ,其次为草蛉和食蚜蝇 ;在寄生性天敌昆虫中 ,蚜茧蜂为优势种 ,其次为寄蝇 ;在植食性昆虫中 ,麦长管蚜为绝对的优势种 ,其次为赤须盲蝽、灰飞虱和麦蓟马。天敌昆虫对害虫具有明显的跟随现象 ,不能有效地控制麦长管蚜的发生与危害。依据昆虫群落的组成与结构 ,结合小麦生育期 ,采用最优分割法将麦田昆虫群落动态划分为 5个阶段 ,并指出不同阶段昆虫群落特点及相应的害虫防治策略。     

Enzymes for ecdysteroid biosynthesis: their biological functions in insects and beyond

Steroid hormones are responsible for the coordinated regulation of many aspects of biological processes in multicellular organisms. Since the last century, many studies have identified and characterized steroidogenic enzymes in vertebrates, including mammals. However, much less is known about invertebrate steroidogenic enzymes. In the last 15?years, a number of steroidogenic enzymes and their functions have been characterized in ecdysozoan animals, especially in the fruit fly Drosophila melanogaster. In this review, we summarize the latest knowledge of enzymes crucial for synthesizing ecdysteroids, the principal insect steroid hormones. We also discuss the functional conservation and diversity of ecdysteroidogenic enzymes in other insects and even non-insect species, such as nematodes, vertebrates, and lower eukaryotes.     

Invertebrate aquaporins: a review

Aquaporins (AQPs) or water channels render the lipid bilayer of cell membranes permeable to water. The numerous AQP subtypes present in any given species, the transport properties of each subtype and the variety of methods of their regulation allows different cell types to be transiently or permanently permeable to water or other solutes that AQPs are capable of transporting (e.g. urea or glycerol). AQPs have been well characterized in all vertebrate classes, other than reptilia. Here we review the current state of knowledge of invertebrate AQPs set in the context of the much more thoroughly studied vertebrate AQPs. By phylogenetic analysis of the total AQP complement of several completed insect genomes, we propose a classification system of insect AQPs including three sub-families (DRIP, BIB and PRIP) that have one representative from all the complete insect genomes. The physiological role of AQPs in invertebrates (insects, ticks and nematodes) is discussed, including their function in common invertebrate phenomena such as high-volume liquid diets, cryoprotection and anhydrobiosis.     

Evolutionary conservation and versatility of a new set of primers for amplifying the ribosomal internal transcribed spacer regions in insects and other invertebrates

The evolutionary conservation and versatility of a new set of nuclear primers for the amplification of the ribosomal internal transcribed spacer regions in insects and other invertebrates have been studied. These primers, conserved across Insecta and other invertebrates, are based on a comprehensive taxonomic survey of the current DNA sequence databases. Their versatility was demonstrated by extensive polymerase chain reaction assays in 16 species from two arachnid orders, eight insect orders, three invertebrate and vertebrate chordate orders and by direct sequencing of the amplified products. The availability of these primers to the insect research community should facilitate the use of internal transcribed spacer regions in intraspecific studies as well as phylogenetic analysis of closely related taxa.     

Isolation,identification, and synthesis of Mas-MG-MT I,a novel peptide from the larval midgut of Manduca sexta (lepidoptera: Sphingidae)

A five-residue myotropic peptide, Manduca sexta midgut myotropin I (Mas-MG-MT I), was isolated from an extract of 800 midguts of fifth instar larvae of the tobacco hornworm, Manduca sexta. It was purified by reverse phase and normal phase HPLC. Myotropic activity was screened by a heterologous Locusta migratoria oviduct bioassay. Sequence analysis, amino acid composition analysis, and comparison of candidate synthetic peptides in the amide and acid form revealed the following primary structure: Ala-Glu-Pro-Tyr-Thr-NH₂. This is the first fully identified peptide isolated directly from the midgut of an insect species. Few significant sequence homologies with known vertebrate and invertebrate peptides have been found. © 1995 Wiley-Liss, Inc.     

Ancient Cytokines,the Role of Astakines as Hematopoietic Growth Factors

Hematopoiesis is the process by which hemocytes mature and subsequently enter the circulation. Vertebrate prokineticins (PKs) are known to take part in this process, as are the invertebrate prokineticin domain proteins, astakines. In Pacifastacus leniusculus, astakine 1 is essential for the release of new hemocytes into the open circulatory system of these animals. In addition to astakine 1, we have now cloned a homologue of astakine 1 with an insert of 13 amino acids, named as astakine 2. Both crustacean astakines lack the N-terminal AVIT motif, which is present in vertebrate PKs, and hence receptor binding differs from that of vertebrate PKs. We have found astakine-like sequences in 19 different invertebrate species, and the sequences show that some motifs are conserved among invertebrate groups. Previously we showed that astakine 1 is directly involved in hematopoiesis, and now we show that astakine 1 and astakine 2 have different roles in hemocyte lineage differentiation. Astakine 1 can stimulate proliferation of hematopoietic tissue (Hpt) cells (precursor of hemocytes) as well as specifically induce differentiation of Hpt cells along the semigranular cell lineage, whereas astakine 2 plays a role in granular cell differentiation. Moreover, we discuss the impact of the putative structures of different astakines in comparison with the vertebrate prokineticins.