Occurrence of the cis‐4,7,10, trans‐13‐22:4 Fatty Acid in the Family Pectinidae (Mollusca: Bivalvia)

Abstract

The present study aimed to elucidate the effective phylogenetic specificity of distribution of a cis-4,7,10, trans-13-22:4 (22:4(n-9)Delta13trans) among pectinids. For this purpose, we extended the analysis of membrane glycerophospholipids FA composition to 13 species of scallops, covering 11 genera and 7 tribes representatives of the three subfamilies Chlamydinae, Palliolinae and Pectininae and the subgroup Aequipecten. In species belonging to the subfamily Pectininae and the Aequipecten subgroup, 22:4(n-9)Delta13trans was found in substantial amounts, but it was absent in other species belonging to the subfamilies Chlamydinae and Palliolinae. Homologous non-methylene-interrupted (NMI) FA, also hypothesized to differ along phylogenetic lines in bivalves, were totally absent or present only in trace amounts in representatives of the Aequipecten subgroup but ranged from 0.3 to 4.5% of the total FA in Pectinidae, Chlamydinae, and Palliolinae subfamilies. The species-specific occurrence of NMI and 22:4(n-9)Delta13trans FA in membrane lipids of pectinids agrees with the most recent phylogenies based on shell morphology and molecular characteristics. We examined the potential timing of the appearance of 22:4(n-9)Delta13trans in pectinids on a geologic time scale.

Specific regulations of gill membrane fatty acids in response to environmental variability reveal fitness differences between two suspension-feeding bivalves (Nodipecten subnodosus and Spondylus crassisquama)

“…As for plasmalogens (DMA), these differences of regulations of NMI FA between species suggest different strategies or capacities to cope with environmental conditions. The same conclusion can be made for 20:1n-11 and 22:4n-9trans that were associated to NMI FA to confer similar functions as NMI to tissues ( Kraffe et al , 2010 ; Le Grand et al , 2011 ). Indeed, although 20:1n-11 markedly increased in individuals of S. crassisquama in August as for NMI, this was much less pronounced for N. subnodosus , and 22:4n-9trans was at lower proportions.…”

“…These modifications could contribute to the structural and functional regulations of membranes as NMI FAs were suggested to confer a resistance to tissues during microbial attack ( Paradis and Ackman, 1977 ) and during temperature changes ( Pirini et al , 2007 ) and also provide protection against oxidation ( Kraffe et al , 2004 ; Delaporte et al , 2005 ; Barnathan, 2009 ; Le Grand et al , 2013 ). The 20:1n-11 and 22:4n-9 trans were associated to NMI FA to confer resistance and similar functions as NMI to tissues ( Kraffe et al , 2010 ; Le Grand et al , 2011 ). Because NMI, 22:4n-9 trans and 20:1n-11 FA were absent from the potential food sources such as particulate organic matter and sedimentary organic matter ( Mathieu-Resuge et al , 2019a ), their presence in the bivalves tissues is most likely explained by de novo synthesis.…”

Diet and performance in the scallop,Argopecten purpuratus: force production during escape responses and mitochondrial oxidative capacities

“…FAME were analysed in a Varian CP 8400 gas chromatograph equipped with an on-column injector and a flame ionisation detector. FA were identified by comparing their retention times using both polar (CPWAX 52 CB -30 m × 0.25 mm, 0.25 μm film thickness) and non-polar (CP-Sil 8 CB -30 m × 0.25 mm, 0.25 μm film thickness) capillary columns by means of a standard mixture containing 37 FAME (SUPELCO/Sigma-Aldrich, St-Quentin Fallavier, France), and other known standard mixtures from pectinids (Kraffe et al 2010). …”