Chemical Ecology, Biochemistry, and Molecular Biology of Insect Hydrocarbons

2021 ◽  
Vol 66 (1) ◽  
pp. 45-60
Author(s):  
Gary J. Blomquist ◽  
Matthew D. Ginzel
Keyword(s):  
Fatty Acids ◽  
Rna Interference ◽  
Molecular Biology ◽  
Water Loss ◽  
Life Histories ◽  
Complex Mixtures ◽  
Straight Chain ◽  
Branched Hydrocarbons ◽  
Insect Hydrocarbons ◽  
Hydrocarbon Biosynthesis

Insect cuticular hydrocarbons (CHCs) consist of complex mixtures of straight-chain alkanes and alkenes, and methyl-branched hydrocarbons. In addition to restricting water loss through the cuticle and preventing desiccation, they have secondarily evolved to serve a variety of functions in chemical communication and play critical roles as signals mediating the life histories of insects. In this review, we describe the physical properties of CHCs that allow for both waterproofing and signaling functions, summarize their roles as inter- and intraspecific chemical signals, and discuss the influences of diet and environment on CHC profiles. We also present advances in our understanding of hydrocarbon biosynthesis. Hydrocarbons are biosynthesized in oenocytes and transported to the cuticle by lipophorin proteins. Recent work on the synthesis of fatty acids and their ultimate reductive decarbonylation to hydrocarbons has taken advantage of powerful new tools of molecular biology, including genomics and RNA interference knockdown of specific genes, to provide new insights into the biosynthesis of hydrocarbons.

scholarly journals Dissecting the Roles of Cuticular Wax in Plant Resistance to Shoot Dehydration and Low-Temperature Stress in Arabidopsis

2021 ◽  
Vol 22 (4) ◽  
pp. 1554
Author(s):  
Tawhidur Rahman ◽  
Mingxuan Shao ◽  
Shankar Pahari ◽  
Prakash Venglat ◽  
Raju Soolanayakanahally ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Low Temperature ◽  
Cold Acclimation ◽  
Water Loss ◽  
Cuticular Wax ◽  
Dehydration Stress ◽  
Wax Deposition ◽  
Cuticular Waxes ◽  
Gas Chromatography Mass Spectroscopy

Cuticular waxes are a mixture of hydrophobic very-long-chain fatty acids and their derivatives accumulated in the plant cuticle. Most studies define the role of cuticular wax largely based on reducing nonstomatal water loss. The present study investigated the role of cuticular wax in reducing both low-temperature and dehydration stress in plants using Arabidopsis thaliana mutants and transgenic genotypes altered in the formation of cuticular wax. cer3-6, a known Arabidopsis wax-deficient mutant (with distinct reduction in aldehydes, n-alkanes, secondary n-alcohols, and ketones compared to wild type (WT)), was most sensitive to water loss, while dewax, a known wax overproducer (greater alkanes and ketones compared to WT), was more resistant to dehydration compared to WT. Furthermore, cold-acclimated cer3-6 froze at warmer temperatures, while cold-acclimated dewax displayed freezing exotherms at colder temperatures compared to WT. Gas Chromatography-Mass Spectroscopy (GC-MS) analysis identified a characteristic decrease in the accumulation of certain waxes (e.g., alkanes, alcohols) in Arabidopsis cuticles under cold acclimation, which was additionally reduced in cer3-6. Conversely, the dewax mutant showed a greater ability to accumulate waxes under cold acclimation. Fourier Transform Infrared Spectroscopy (FTIR) also supported observations in cuticular wax deposition under cold acclimation. Our data indicate cuticular alkane waxes along with alcohols and fatty acids can facilitate avoidance of both ice formation and leaf water loss under dehydration stress and are promising genetic targets of interest.

scholarly journals Recent Advances in the Development of Exogenous dsRNA for the Induction of RNA Interference in Cancer Therapy

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 701
Author(s):  
Tatiana S. Golubeva ◽  
Viktoria A. Cherenko ◽  
Konstantin E. Orishchenko
Keyword(s):  
Gene Expression ◽  
Rna Interference ◽  
Molecular Biology ◽  
Gene Silencing ◽  
Regulation Of Gene Expression ◽  
Research Area ◽  
Disease Treatment ◽  
Practical Applications ◽  
Agricultural Plants ◽  
Insect Reproduction

Selective regulation of gene expression by means of RNA interference has revolutionized molecular biology. This approach is not only used in fundamental studies on the roles of particular genes in the functioning of various organisms, but also possesses practical applications. A variety of methods are being developed based on gene silencing using dsRNA—for protecting agricultural plants from various pathogens, controlling insect reproduction, and therapeutic techniques related to the oncological disease treatment. One of the main problems in this research area is the successful delivery of exogenous dsRNA into cells, as this can be greatly affected by the localization or origin of tumor. This overview is dedicated to describing the latest advances in the development of various transport agents for the delivery of dsRNA fragments for gene silencing, with an emphasis on cancer treatment.

TetR-family transcriptional repressor Thermus thermophilus FadR controls fatty acid degradation

Microbiology ◽  
2011 ◽  
Vol 157 (6) ◽  
pp. 1589-1601 ◽  
Author(s):  
Yoshihiro Agari ◽  
Kazuko Agari ◽  
Keiko Sakamoto ◽  
Seiki Kuramitsu ◽  
Akeo Shinkai
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Target Genes ◽  
Thermus Thermophilus ◽  
Acyl Chain ◽  
Metabolic Energy ◽  
Straight Chain ◽  
Fatty Acid Degradation ◽  
Acid Degradation

In the extremely thermophilic bacterium Thermus thermophilus HB8, one of the four TetR-family transcriptional regulators, which we named T. thermophilus FadR, negatively regulated the expression of several genes, including those involved in fatty acid degradation, both in vivo and in vitro. T. thermophilus FadR repressed the expression of the target genes by binding pseudopalindromic sequences covering the predicted −10 hexamers of their promoters, and medium-to-long straight-chain (C10–18) fatty acyl-CoA molecules were effective for transcriptional derepression. An X-ray crystal structure analysis revealed that T. thermophilus FadR bound one lauroyl (C12)-CoA molecule per FadR monomer, with its acyl chain moiety in the centre of the FadR molecule, enclosed within a tunnel-like substrate-binding pocket surrounded by hydrophobic residues, and the CoA moiety interacting with basic residues on the protein surface. The growth of T. thermophilus HB8, with palmitic acid as the sole carbon source, increased the expression of FadR-regulated genes. These results indicate that in T. thermophilus HB8, medium-to-long straight-chain fatty acids can be used for metabolic energy under the control of FadR, although the major fatty acids found in this strain are iso- and anteiso-branched-chain (C15 and 17) fatty acids.

scholarly journals Separation of Saturated Straight Chain Fatty Acids. Qualitative Paper Chromatography.

1955 ◽  
Vol 9 ◽  
pp. 864-865 ◽  
Author(s):  
Olavi Perilä ◽  
Rolf Gmelin ◽  
Ivan Larsen ◽  
Ole Lamm
Keyword(s):  
Fatty Acids ◽  
Paper Chromatography ◽  
Straight Chain ◽  
Chain Fatty Acids

scholarly journals Pseudoalteromonas byunsanensis sp. nov., isolated from tidal flat sediment in Korea

2005 ◽  
Vol 55 (6) ◽  
pp. 2519-2523 ◽  
Author(s):  
Yoon-Dong Park ◽  
Keun Sik Baik ◽  
Hana Yi ◽  
Kyung Sook Bae ◽  
Jongsik Chun
Keyword(s):  
Fatty Acids ◽  
Tidal Flat ◽  
Gene Sequence ◽  
Novel Species ◽  
Rrna Gene ◽  
Strictly Aerobic ◽  
Straight Chain ◽  
Tidal Flat Sediment ◽  
Distinct Line ◽  
The 16S Rrna Gene

A Gram-negative, motile, strictly aerobic, violet-pigment-producing bacterium, designated strain FR1199T, was isolated from tidal flat sediment of Byunsan, South Korea. Phylogenetic analysis of the 16S rRNA gene sequence revealed that strain FR1199T represents a distinct line of descent within the genus Pseudoalteromonas. The phenotypic features of strain FR1199T were similar to those of Pseudoalteromonas phenolica and Pseudoalteromonas luteoviolacea, but several physiological and chemotaxonomical properties readily distinguished strain FR1199T from these species. Major fatty acids were straight-chain saturated (C16 : 0) and monounsaturated C18 : 1 ω7c fatty acids. The DNA G+C content was 39 mol%. On the basis of polyphasic evidence, it is concluded that the isolate represents a novel species within the genus Pseudoalteromonas, for which the name Pseudoalteromonas byunsanensis sp. nov. is proposed. The type strain is FR1199T (=JCM 12483T=KCTC 12274T).

scholarly journals The Peroxisomal Acyl-CoA Thioesterase Pte1p fromSaccharomyces cerevisiaeIs Required for Efficient Degradation of Short Straight Chain and Branched Chain Fatty Acids

2006 ◽  
Vol 281 (17) ◽  
pp. 11729-11735 ◽  
Author(s):  
Isamu Maeda ◽  
Syndie Delessert ◽  
Seiko Hasegawa ◽  
Yoshiaki Seto ◽  
Sophie Zuber ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Straight Chain ◽  
Branched Chain Fatty Acids ◽  
Branched Chain ◽  
Chain Fatty Acids

THE NORMAL C17 FATTY ACIDS OF MUSK-OX FAT

1957 ◽  
Vol 35 (12) ◽  
pp. 1434-1437 ◽  
Author(s):  
Mary J. Chisholm ◽  
C. Y. Hopkins
Keyword(s):  
Fatty Acids ◽  
Melting Point ◽  
Mixed Melting Point ◽  
Methyl Esters ◽  
Heptadecanoic Acid ◽  
X Ray Diffraction ◽  
Straight Chain ◽  
Trans Form ◽  
Total Fatty Acids ◽  
Musk Ox

A sample of body fat of the Canadian musk ox (Ovibosmoschatus subsp.) was converted to methyl esters and distilled. The fraction containing esters of C17 acids was crystallized fractionally at low temperature and two straight-chain C17 acids were isolated. n-Heptadecanoic acid was identified by analysis, by mixed melting point of the acid and two derivatives with authentic samples, and by its X-ray diffraction pattern. 9-Heptadecenoic acid was identified by analysis, by mixed melting point of two derivatives with authentic samples, and by oxidative cleavage. It is estimated that the fat contained 1.7% of n-heptadecanoic acid and 0.9% of cis-9-heptadecenoic acid, based on the total fatty acids. Although there was an appreciable content of trans acids in the fat, the heptadecenoic acid was found to contain little or none of the trans form.

Acid-Adapted Listeria monocytogenes Displays Enhanced Tolerance against the Lantibiotics Nisin and Lacticin 3147

1999 ◽  
Vol 62 (5) ◽  
pp. 536-540 ◽  
Author(s):  
WILLEM van SCHAIK ◽  
CORMAC G. M. GAHAN ◽  
COLIN HILL
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Listeria Monocytogenes ◽  
Bacterial Membrane ◽  
Straight Chain ◽  
Distinct Mode ◽  
Acid Adaptation ◽  
Lacticin 3147 ◽  
Acidic Conditions ◽  
Moderate Effect

Log-phase Listeria monocytogenes cells become tolerant to a variety of environmental stresses following acid adaptation at pH 5.5. We demonstrated that adapted cells also exhibit increased tolerance to nisin and, to a lesser extent, lacticin 3147. At nisin concentrations of 100 and 200 IU/ml the survival of acid-adapted cells was approximately 10-fold greater than nonadapted cells. However, acid adaptation had only a moderate effect on the tolerance of L. monocytogenes to lacticin 3147, a phenomenon that possibly reflects the distinct mode of action of this bacteriocin. Analysis of the fatty acid composition of the bacterial membrane indicated that straight-chain fatty acids C14:0 and C16:0 were significantly increased in acid-adapted cells while levels of C18:0 decreased. The results indicate that stress mechanisms that are induced in mildly acidic conditions provide protection against the antimicrobial action of bacteriocins. This increased resistance of acid-adapted L. monocytogenes could cause increased survival of this pathogen in food products in which nisin or other bacteriocins are used as preservatives.

Toxicity of Some Straight Chain Saturated Fatty Acids to House Fly Larvae1

1965 ◽  
Vol 58 (3) ◽  
pp. 400-402 ◽  
Author(s):  
M. Sayeed Quraishi ◽  
A. J. Thorsteinson
Keyword(s):  
Fatty Acids ◽  
Saturated Fatty Acids ◽  
House Fly ◽  
Straight Chain
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