Christeller JT

References (4)

Title : The digestion of galactolipids and its ubiquitous function in Nature for the uptake of the essential alpha-linolenic acid - Sahaka_2020_Food.Funct_11_6710
Author(s) : Sahaka M , Amara S , Wattanakul J , Gedi MA , Aldai N , Parsiegla G , Lecomte J , Christeller JT , Gray D , Gontero B , Villeneuve P , Carriere F
Ref : Food Funct , 11 :6710-6744 , 2020
Abstract : Galactolipids, mainly monogalactosyl diglycerides and digalactosyl diglycerides are the main lipids found in the membranes of plants, algae and photosynthetic microorganisms like microalgae and cyanobacteria. As such, they are the main lipids present at the surface of earth. They may represent up to 80% of the fatty acid stocks, including a large proportion of polyunsaturated fatty acids mainly alpha-linolenic acid (ALA). Nevertheless, the interest in these lipids for nutrition and other applications remains overlooked, probably because they are dispersed in the biomass and are not as easy to extract as vegetable oils from oleaginous fruit and oil seeds. Another reason is that galactolipids only represent a small fraction of the acylglycerolipids present in modern human diet. In herbivores such as horses, fish and folivorous insects, galactolipids may however represent the main source of dietary fatty acids due to their dietary habits and digestion physiology. The development of galactolipase assays has led to the identification and characterization of the enzymes involved in the digestion of galactolipids in the gastrointestinal tract, as well as by microorganisms. Pancreatic lipase-related protein 2 (PLRP2) has been identified as an important factor of galactolipid digestion in humans, together with pancreatic carboxyl ester hydrolase (CEH). The levels of PLRP2 are particularly high in monogastric herbivores thus highlighting the peculiar role of PLRP2 in the digestion of plant lipids. Similarly, pancreatic lipase homologs are found to be expressed in the midgut of folivorous insects, in which a high galactolipase activity can be measured. In fish, however, CEH is the main galactolipase involved. This review discusses the origins and fatty acid composition of galactolipids and the physiological contribution of galactolipid digestion in various species. This overlooked aspect of lipid digestion ensures not only the intake of ALA from its main natural source, but also the main lipid source of energy for growth of some herbivorous species.
ESTHER : Sahaka_2020_Food.Funct_11_6710
PubMedSearch : Sahaka_2020_Food.Funct_11_6710
PubMedID: 32687132
Gene_locus related to this paper: helam-a0a2w1b5z2 , cavpo-2plrp

Title : Genomic innovations, transcriptional plasticity and gene loss underlying the evolution and divergence of two highly polyphagous and invasive Helicoverpa pest species - Pearce_2017_BMC.Biol_15_63
Author(s) : Pearce SL , Clarke DF , East PD , Elfekih S , Gordon KHJ , Jermiin LS , McGaughran A , Oakeshott JG , Papanicolaou A , Perera OP , Rane RV , Richards S , Tay WT , Walsh TK , Anderson A , Anderson CJ , Asgari S , Board PG , Bretschneider A , Campbell PM , Chertemps T , Christeller JT , Coppin CW , Downes SJ , Duan G , Farnsworth CA , Good RT , Han LB , Han YC , Hatje K , Horne I , Huang YP , Hughes DST , Jacquin-Joly E , James W , Jhangiani S , Kollmar M , Kuwar SS , Li S , Liu NY , Maibeche MT , Miller JR , Montagne N , Perry T , Qu J , Song SV , Sutton GG , Vogel H , Walenz BP , Xu W , Zhang HJ , Zou Z , Batterham P , Edwards OR , Feyereisen R , Gibbs RA , Heckel DG , McGrath A , Robin C , Scherer SE , Worley KC , Wu YD
Ref : BMC Biol , 15 :63 , 2017
Abstract : BACKGROUND: Helicoverpa armigera and Helicoverpa zea are major caterpillar pests of Old and New World agriculture, respectively. Both, particularly H. armigera, are extremely polyphagous, and H. armigera has developed resistance to many insecticides. Here we use comparative genomics, transcriptomics and resequencing to elucidate the genetic basis for their properties as pests. RESULTS: We find that, prior to their divergence about 1.5 Mya, the H. armigera/H. zea lineage had accumulated up to more than 100 more members of specific detoxification and digestion gene families and more than 100 extra gustatory receptor genes, compared to other lepidopterans with narrower host ranges. The two genomes remain very similar in gene content and order, but H. armigera is more polymorphic overall, and H. zea has lost several detoxification genes, as well as about 50 gustatory receptor genes. It also lacks certain genes and alleles conferring insecticide resistance found in H. armigera. Non-synonymous sites in the expanded gene families above are rapidly diverging, both between paralogues and between orthologues in the two species. Whole genome transcriptomic analyses of H. armigera larvae show widely divergent responses to different host plants, including responses among many of the duplicated detoxification and digestion genes. CONCLUSIONS: The extreme polyphagy of the two heliothines is associated with extensive amplification and neofunctionalisation of genes involved in host finding and use, coupled with versatile transcriptional responses on different hosts. H. armigera's invasion of the Americas in recent years means that hybridisation could generate populations that are both locally adapted and insecticide resistant.
ESTHER : Pearce_2017_BMC.Biol_15_63
PubMedSearch : Pearce_2017_BMC.Biol_15_63
PubMedID: 28756777
Gene_locus related to this paper: helam-a0a2w1bn75 , helam-a0a2w1bp69 , helam-a0a2w1bvf3

Title : Galactolipase, phospholipase and triacylglycerol lipase activities in the midgut of six species of lepidopteran larvae feeding on different lipid diets - Christeller_2011_J.Insect.Physiol_57_1232
Author(s) : Christeller JT , Amara S , Carriere F
Ref : J Insect Physiol , 57 :1232 , 2011
Abstract : Galactolipase, phospholipase and triacylglycerol lipase activities were measured from the midgut of six species of lepidopteran larvae, two folivores, Epiphyas postvittana (Tortricidae) and Helicoverpa armigera (Noctuidae); two granivores, Plodia interpunctella (Pyralidae) and Ephestia kuehniella (Pyrallidae); a presumptive carnivore, Galleria mellonella (Pyralidae); and a keratinophage, Tineola bisselliella (Tineidae). Galactolipase has not been previously reported in insects. Galactolipase and phospholipase activities were high in the folivores and triacylglycerol lipase activity was low, matching the high galactolipid content of leaves. Conversely, galactolipase and phospholipase activities were low, but not absent, and triacylglycerol lipase activity high in the four other non-folivorous species, matching the high acylglycerol content of their diets. These data suggest the utility of reclassification, for evolutionary studies, of phytophagous lepidoptera into two feeding classes; folivore and granivore, the latter having similarity to the fungivore line of feeders in terms of its lipase activities and ability to retrieve essential polyunsaturated long chain fatty acids from their diets. All the digestive lipases have alkaline pH optima for activity, matching the pH of the lepidopteran midgut and their amino acid content show modifications likely to stabilize the proteins in that environment.
ESTHER : Christeller_2011_J.Insect.Physiol_57_1232
PubMedSearch : Christeller_2011_J.Insect.Physiol_57_1232
PubMedID: 21704634

Title : The effect of diet on the expression of lipase genes in the midgut of the lightbrown apple moth (Epiphyas postvittana Walker\; Tortricidae) - Christeller_2010_Insect.Mol.Biol_19_9
Author(s) : Christeller JT , Poulton J , Markwick NM , Simpson RM
Ref : Insect Molecular Biology , 19 :9 , 2010
Abstract : We have identified lipase-like genes from an Epiphyas postvittana larval midgut EST library. Of the 10 pancreatic lipase family genes, six appear to encode active lipases and four encode inactive lipases, based on the presence/absence of essential catalytic residues. The four gastric lipase family genes appear to encode active proteins. Phylogenetic analysis of 54 lepidopteran pancreatic lipase proteins resolved the clade into five groups of midgut origin and a sixth of non-midgut lipases. The inactive proteins formed two separate groups with highly conserved mutations. The lepidopteran midgut lipases formed a ninth subfamily of pancreatic lipases. Eighteen insect and human gastric lipases were analysed phylogenetically with only very weak support for any groupings. Gene expression was measured in the larval midgut following feeding on five artificial diets and on apple leaves. The artificial diets contained different levels of triacylglycerol, linoleic acid and cholesterol. Significant changes in gene expression (more than 100-fold for active pancreatic lipases) were observed. All the inactive lipases were also highly expressed. The gastric lipase genes were expressed at lower levels and suppressed in larvae feeding on leaves. Together, protein motif analysis and the gene expression data suggest that, in phytophagous lepidopteran larvae, the pancreatic lipases may function in vivo as galactolipases and phospholipases whereas the gastric lipases may function as triacylglycerol hydrolases.
ESTHER : Christeller_2010_Insect.Mol.Biol_19_9
PubMedSearch : Christeller_2010_Insect.Mol.Biol_19_9
PubMedID: 20002216