Project description:The accessory nidamental gland (ANG) is part of the reproduction organ in the majority of female cephalopods, including the bigfin reef squid Sepioteuthis lessoniana, an economically important fishery product. Microbes in Alphaproteobacteria, Gammaproteobacteria, and Verrucomicrobia have been suggested to play a role in the maturation of the S. lessoniana ANG and are responsible for its color. However, the bacterial composition and dynamics of the different maturation stages of the ANG remain unclear. In the present study, we surveyed ANG-associated bacterial dynamics in wild-caught S. lessoniana at various developmental stages in different populations over 3 years. The results obtained showed that the ANG bacterial community shifted gradually and decreased in diversity throughout maturation. Verrucomicrobia occupied the ANG during the early stages in large numbers, and was replaced by Bacteroidia, Alphaproteobacteria, and Gammaproteobacteria in the later stages. Flavobacteriales and Alphaproteobacteria both appeared to contribute to pigmentation, while Bacteroidia, Alphaproteobacteria, and Gammaproteobacteria may be involved in enriching the heme biosynthesis pathway in the ANG with the maturation of S. lessoniana. The present results provide an open question of whether S. lessoniana actively selects the bacterial community in the ANG to adjust to its surrounding environment.
Project description:In the current study, the squid, Sepioteuthis lessoniana ink was used as a raw material. It summarizes physicochemical, elemental, and spectral properties (UV/Visible spectroscopy and FT-IR) of crude ink, whereas the biochemical analysis was performed with crude ink (CI) as well as melanin-free ink (MFI). The percentage yield was analyzed using various solvent extracts of CI and MFI. GC-MS was performed for the chemical constituents of the methanolic extract of ink. Furthermore, the methanolic extract was subjected to various biological applications. The physicochemical analysis defines the presence of moisture, ash, extractive value, solubility, and thermal stability of CI. The biochemical analysis reveals protein, lipid, and carbohydrate of 2.5, 2.2, and 2.37 mg/ml for CI and 2.8, 3.7, and 4.51 mg/ml for MFI respectively. The extract showed the highest zone of inhibition at 100 μg/ml. The antioxidant activity reveals the highest percentage of radical-scavenging activity in nitric oxide (NO) (89%), and total antioxidant capacity (TAC) assay showed the highest inhibition activity of 0.41 nm at 100 µg/ml. The cytotoxic ability of methanolic extract against MDA-MB-231 breast cancer cell line revealed an IC50 value of 10.13 μg/ml. Toxicity assay showed increased mortality of Artemia nauplii at higher concentrations (1000 ppm/40%) of extract. These findings indicate that S. lessoniana ink is a novel prospective product that needs to be characterized in order to increase its pharmacological activity.Supplementary informationThe online version contains supplementary material available at 10.1007/s13205-023-03830-6.
Project description:The oval squid Sepioteuthis lessoniana is one of the most economically important squid species in Japan; however, its population structure is poorly understood due to the lack of hypervariable markers. Such information is critical for managing sustainable fisheries, as well as for ensuring the existence of wild S. lessoniana stocks. Eleven candidate microsatellite loci were isolated from a small insert genomic DNA library. Polymorphisms in these 11 loci were screened in 24 wild individuals. The number of alleles per locus was found to range from 5 to 19 alleles, and the observed heterozygosity ranged from 0.292 to 0.958. No evidence for linkage disequilibrium was detected among all the loci. The genotypic proportions conformed to Hardy-Weinberg equilibrium, except at one locus. In conclusion, these polymorphic microsatellite loci may be used to develop a genetic framework to manage S. lessoniana in the future.