scholarly journals Leucokinins: Multifunctional Neuropeptides and Hormones in Insects and Other Invertebrates

2021 ◽  
Vol 22 (4) ◽  
pp. 1531 ◽  
Author(s):  
Dick R. Nässel ◽  
Shun-Fan Wu
Keyword(s):  
Ventral Nerve Cord ◽  
Neurosecretory Cells ◽  
Malpighian Tubules ◽  
Simple Pattern ◽  
Functional Roles ◽  
State Dependent ◽  
Different Types ◽  
Genes Encoding ◽  
Drosophila Larva ◽  
Neuronal Distribution

Leucokinins (LKs) constitute a neuropeptide family first discovered in a cockroach and later identified in numerous insects and several other invertebrates. The LK receptors are only distantly related to other known receptors. Among insects, there are many examples of species where genes encoding LKs and their receptors are absent. Furthermore, genomics has revealed that LK signaling is lacking in several of the invertebrate phyla and in vertebrates. In insects, the number and complexity of LK-expressing neurons vary, from the simple pattern in the Drosophila larva where the entire CNS has 20 neurons of 3 main types, to cockroaches with about 250 neurons of many different types. Common to all studied insects is the presence or 1–3 pairs of LK-expressing neurosecretory cells in each abdominal neuromere of the ventral nerve cord, that, at least in some insects, regulate secretion in Malpighian tubules. This review summarizes the diverse functional roles of LK signaling in insects, as well as other arthropods and mollusks. These functions include regulation of ion and water homeostasis, feeding, sleep–metabolism interactions, state-dependent memory formation, as well as modulation of gustatory sensitivity and nociception. Other functions are implied by the neuronal distribution of LK, but remain to be investigated.

scholarly journals Leucokinins: Multifunctional Neuropeptides and Hormones in Insects and Other Invertebrates

2021 ◽  
Author(s):  
Dick R. Nässel ◽  
Shun-Fan Wu
Keyword(s):  
Ventral Nerve Cord ◽  
Neurosecretory Cells ◽  
Memory Formation ◽  
Malpighian Tubules ◽  
Simple Pattern ◽  
Functional Roles ◽  
State Dependent ◽  
Different Types ◽  
Genes Encoding ◽  
Neuronal Distribution

Leucokinins (LKs) constitute a neuropeptide family first discovered in a cockroach and later identified in numerous insects and several other invertebrates. The LK receptors are only distantly related to other known receptors. Among insects, there are many examples of species where genes encoding LKs and their receptors are absent. Furthermore, genomics has revealed that LK signaling is lacking in several of the invertebrate phyla and in vertebrates. In insects, the number and complexity of LK expressing neurons vary, from the simple pattern in the larva of Drosophila where the entire CNS has 20 neurons of three main types, to cockroaches with about 250 of many different types. Common to all studied insects is the presence or 1-3 pairs of LK-expressing neurosecretory cells in each abdominal neuromere of the ventral nerve cord, that, at least in some insects, regulate secretion in Malpighian tubules. This review summarizes the diverse functional roles of LK signaling in insects, as well as other arthropods and mollusks. These functions include regulation of ion and water homeostasis, feeding, sleep-metabolism interactions, state-dependent memory formation, as well as modulation of gustatory sensitivity and nociception. Other functions are implied by the neuronal distribution of LK, but remain to be investigated.

scholarly journals Leucokinin and Associated Neuropeptides Regulate Multiple Aspects of Physiology and Behavior in Drosophila

2021 ◽  
Author(s):  
Dick R. Nässel
Keyword(s):  
Ion Homeostasis ◽  
Neurosecretory Cells ◽  
Functional Roles ◽  
State Dependent ◽  
Drosophila Larvae ◽  
And Behavior ◽  
G Protein Coupled ◽  
The Brain ◽  
Adult Drosophila

Leucokinins (LKs) constitute a family of neuropeptides identified in numerous insects and many other invertebrates. The LKs act on G-protein coupled receptors that display only distant relations to other known receptors. In adult Drosophila, 26 neurons/neurosecretory cells of three main types express LK. The four brain interneurons are of two types, and these are implicated in several important functions in the fly’s behavior and physiology, including feeding, sleep-metabolism interactions, state-dependent memory formation, as well as modulation of gustatory sensitivity and nociception. The 22 neurosecretory cells (ABLKs) of the abdominal neuromeres coexpress LK and a diuretic hormone (DH44), and together these regulate water and ion homeostasis and associated stress, as well as food intake. In Drosophila larvae, LK neurons modulate locomotion, escape responses, and aspects of ecdysis behavior. A set of lateral neurosecretory cells, ALKs, in the brain express LK in larvae, but inconsistently so in adults. These ALKs coexpress three other neuropeptides and regulate water and ion homeostasis, feeding and drinking, but the specific role of LK is not yet known. This review summarizes Drosophila data on embryonic lineages of LK neurons, functional roles of individual LK neuron types, interactions with other peptidergic systems, and orchestrating functions of LK.

scholarly journals Leucokinin and Associated Neuropeptides Regulate Multiple Aspects of Physiology and Behavior in Drosophila

2021 ◽  
Vol 22 (4) ◽  
pp. 1940
Author(s):  
Dick R. Nässel
Keyword(s):  
Ion Homeostasis ◽  
Neurosecretory Cells ◽  
Functional Roles ◽  
State Dependent ◽  
Drosophila Larvae ◽  
And Behavior ◽  
G Protein Coupled ◽  
The Brain ◽  
Adult Drosophila

Leucokinins (LKs) constitute a family of neuropeptides identified in numerous insects and many other invertebrates. LKs act on G-protein-coupled receptors that display only distant relations to other known receptors. In adult Drosophila, 26 neurons/neurosecretory cells of three main types express LK. The four brain interneurons are of two types, and these are implicated in several important functions in the fly’s behavior and physiology, including feeding, sleep–metabolism interactions, state-dependent memory formation, as well as modulation of gustatory sensitivity and nociception. The 22 neurosecretory cells (abdominal LK neurons, ABLKs) of the abdominal neuromeres co-express LK and a diuretic hormone (DH44), and together, these regulate water and ion homeostasis and associated stress as well as food intake. In Drosophila larvae, LK neurons modulate locomotion, escape responses and aspects of ecdysis behavior. A set of lateral neurosecretory cells, ALKs (anterior LK neurons), in the brain express LK in larvae, but inconsistently so in adults. These ALKs co-express three other neuropeptides and regulate water and ion homeostasis, feeding, and drinking, but the specific role of LK is not yet known. This review summarizes Drosophila data on embryonic lineages of LK neurons, functional roles of individual LK neuron types, interactions with other peptidergic systems, and orchestrating functions of LK.

scholarly journals Species functional traits and abundance as drivers of multiplex ecological networks: first empirical quantification of inter-layer edge weights

2020 ◽  
Vol 287 (1939) ◽  
pp. 20202127
Author(s):  
S. Hervías-Parejo ◽  
C. Tur ◽  
R. Heleno ◽  
M. Nogales ◽  
S. Timóteo ◽  
...  
Keyword(s):  
Species Traits ◽  
Abundant Species ◽  
Modular Organization ◽  
Vertebrate Species ◽  
Multilayer Network ◽  
Functional Roles ◽  
Different Types ◽  
Seed Dispersers ◽  
Natural Communities

Many vertebrate species act as both plant pollinators and seed-dispersers, thus interconnecting these processes, particularly on islands. Ecological multilayer networks are a powerful tool to explore interdependencies between processes; however, quantifying the links between species engaging in different types of interactions (i.e. inter-layer edges) remains a great challenge. Here, we empirically measured inter-layer edge weights by quantifying the role of individually marked birds as both pollinators and seed-dispersers of Galápagos plant species over an entire year. Although most species (80%) engaged in both functions, we show that only a small proportion of individuals actually linked the two processes, highlighting the need to further consider intra-specific variability in individuals' functional roles. Furthermore, we found a high variation among species in linking both processes, i.e. some species contribute more than others to the modular organization of the multilayer network. Small and abundant species are particularly important for the cohesion of pollinator seed-dispersal networks, demonstrating the interplay between species traits and neutral processes structuring natural communities.

Genomic analysis of Rhodococcus sp. BH4 reveals two genes encoding different types of AHL-lactonase for quorum quenching

2018 ◽  
Vol 44 ◽  
pp. S77-S78
Author(s):  
D.H. Ryu ◽  
S.W. Lee ◽  
S.J. Lee ◽  
H. Jeong ◽  
C.H. Lee ◽  
...  
Keyword(s):  
Genomic Analysis ◽  
Quorum Quenching ◽  
Different Types ◽  
Genes Encoding ◽  
Rhodococcus Sp

A proteomics analysis of adventitious root formation after leaf removal in lotus (Nelumbo nucifera Gaertn.)

2018 ◽  
Vol 73 (9-10) ◽  
pp. 375-389 ◽  
Author(s):  
Libao Cheng ◽  
Huiying Liu ◽  
Runzhi Jiang ◽  
Shuyan Li
Keyword(s):  
Quantitative Polymerase Chain Reaction ◽  
Adventitious Root Formation ◽  
Nelumbo Nucifera ◽  
Leaf Removal ◽  
Proteomics Analysis ◽  
Citrate Cycle ◽  
Different Types ◽  
Genes Encoding ◽  
Polymerase Chain ◽  
Isobaric Tags

AbstractThe formation of adventitious roots (ARs) is an important process for lotus (Nelumbo nucifera), which does not have a well-formed main root. In lotus, the removal of leaves above the waterline significantly promoted AR formation, while the removal of leaves below the waterline inhibited AR formation. Proteins were identified using isobaric tags for relative and absolute quantization technique. The number of proteins decreased with increasing sequencing coverage, and most of the identified proteins had fewer than 10 peptides. In the A1/A0 and A2/A1 stages, 661 and 154 proteins showed increased abundance, respectively, and 498 and 111 proteins showed decreased abundance, respectively. In the B1/B0 and B2/B1 stages, 498 and 436 proteins showed increased abundance, respectively, and 358 and 348 proteins showed decreased abundance, respectively. Among the proteins showing large differences in abundance, 17 were identified as being related to AR formation. Proteins involved in the glycolytic pathway and the citrate cycle showed differences in abundance between the two types of leaf removal. The transcriptional levels of nine genes encoding relevant proteins were assessed by quantitative polymerase chain reaction. The results of this study illustrate the changes in metabolism after different types of leaf removal during AR formation in lotus.

scholarly journals How the Botswana International University of Science and Technology Library Engages its Stakeholders in Connecting Information Resources, Services, and Space

2020 ◽  
Vol 4 (3/4) ◽  
Author(s):  
Ayanda Agnes Lebele
Keyword(s):  
Science And Technology ◽  
Information Resources ◽  
Library Services ◽  
Access To Information ◽  
Functional Roles ◽  
Engagement Strategies ◽  
Different Types ◽  
International University

In the quest to develop more innovative customer-focused library services, the Botswana International University of Science and Technology (BIUST) Library embarked on the development of robust initiatives that involved the engagement of various stakeholders. The emerging consultative and engaging trend is premised on the key values of facilitating access to information and demand-driven inclusive library services. The paper presents how the BIUST Library engages stakeholders in the development of multiple and flexible opportunities to access and use information. In doing so, it describes the recreation of internal library structures, space, and processes in a way that accommodates and demonstrates the categories and functional roles of different types of library stakeholders. The paper further points to how the stakeholders’ cultures and systems create a divide or imbalance in the access and usage of library services. The paper also argues for a need to define library stakeholders and develop engagement strategies that are entity and initiative specific.

Drosophila brachyenteron regulates gene activity and morphogenesis in the gut

Development ◽  
1996 ◽  
Vol 122 (12) ◽  
pp. 3707-3718 ◽  
Author(s):  
J.B. Singer ◽  
R. Harbecke ◽  
T. Kusch ◽  
R. Reuter ◽  
J.A. Lengyel
Keyword(s):  
Genetic Locus ◽  
Malpighian Tubules ◽  
Gene Activity ◽  
Phenotypic Characterization ◽  
Gut Development ◽  
Allelic Series ◽  
Genes Encoding

Chromosomal region 68D/E is required for various aspects of Drosophila gut development; within this region maps the Brachyury homolog T-related gene (Trg), DNA of which rescues the hindgut defects of deficiency 68D/E. From a screen of 13,000 mutagenized chromosomes we identified six non-complementing alleles that are lethal over deficiencies of 68D/E and show a hindgut phenotype. These mutations constitute an allelic series and are all rescued to viability by a Trg transgene. We have named the mutant alleles and the genetic locus they define brachyenteron (byn); phenotypic characterization of the strongest alleles allows determination of the role of byn in embryogenesis. byn expression is activated by tailless, but byn does not regulate itself. byn expression in the hindgut and anal pad primordia is required for the regulation of genes encoding transcription factors (even-skipped, engrailed, caudal, AbdominalB and orthopedia) and cell signaling molecules (wingless and decapentaplegic). In byn mutant embryos, the defective program of gene activity in these primordia is followed by apoptosis (initiated by reaper expression and completed by macrophage engulfment), resulting in severely reduced hindgut and anal pads. Although byn is not expressed in the midgut or the Malpighian tubules, it is required for the formation of midgut constrictions and for the elongation of the Malpighian tubules.

A Novel Approach for Analyzing Single Buffer Queueing Systems with State-Dependent Vacation and Correlated Input Process under Four Different Service Disciplines

2015 ◽  
Vol 6 (3) ◽  
pp. 19-59 ◽  
Author(s):  
Thomas Yew Sing Lee
Keyword(s):  
Performance Measures ◽  
Probability Generating Function ◽  
Performance Measure ◽  
Idle Time ◽  
Separate Analysis ◽  
Input Process ◽  
State Dependent ◽  
Special Cases ◽  
Service Disciplines ◽  
Different Types

The author presents performance analysis of a single buffer multiple-queue system. Four different types of service disciplines (i.e., non-preemptive, pre-emptive repeat different, state dependent random polling and globally gated) are analyzed. His model includes correlated input process and three different types of non-productive time (i.e., switchover, vacation and idle time). Special cases of the model includes server with mixed multiple and single vacations, stopping server with delayed vacation and stopping server with alternating vacation and idle time. For each of the four service disciplines the key performance measures such as average customer waiting time, loss probability, and throughput are computed. The results permit a detailed discussion of how these performance measures depends on the customer arrival rate, the customer service time, the switchover time, the vacation time, and the idle time. Moreover, extensive numerical results are presented and the four service disciplines are compared with respect to the performance measure. Previous studies of the single buffer multiple-queue systems tend to provide separate analysis for the two cases of zero and nonzero switchover time. The author is able to provide a unified analysis for the two cases. His results generalize and improve a number of known results on single buffer multiple-queue systems. Furthermore, this method does not require differentiation while it is needed if one uses the probability generating function approach. Lastly, the author's approach works for all single buffer multiple-queue systems in which the next queue to be served is determines solely on the basis of the occupancy states at the end of the cycle time.

scholarly journals SOX9 Stem-Cell Factor: Clinical and Functional Relevance in Cancer

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Maribel Aguilar-Medina ◽  
Mariana Avendaño-Félix ◽  
Erik Lizárraga-Verdugo ◽  
Mercedes Bermúdez ◽  
José Geovanni Romero-Quintana ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Stem Cell Factor ◽  
Current Knowledge ◽  
Functional Roles ◽  
Novel Treatments ◽  
Specific Subset ◽  
Different Types ◽  
Undifferentiated Cells ◽  
Functional Relevance

Transcriptional and epigenetic embryonic programs can be reactivated in cancer cells. As result, a specific subset of undifferentiated cells with stem-cells properties emerges and drives tumorigenesis. Recent findings have shown that ectoderm- and endoderm-derived tissues continue expressing stem-cells related transcription factors of the SOX-family of proteins such as SOX2 and SOX9 which have been implicated in the presence of cancer stem-like cells (CSCs) in tumors. Currently, there is enough evidence suggesting an oncogenic role for SOX9 in different types of human cancers. This review provides a summary of the current knowledge about the involvement of SOX9 in development and progression of cancer. Understanding the functional roles of SOX9 and clinical relevance is crucial for developing novel treatments targeting CSCs in cancer.

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