menu.header.image.unacom.logo
 

National Committee on Marine Sciences (NCMS)

Permanent URI for this communityhttps://repository.unesco.gov.ph/handle/123456789/6

Browse

Filters

20222

Settings

AGROVOC Keyword: search.filters.agrovoc.DNA sequencesHas files: Yes

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Restriction site-associated DNA sequencing reveals local adaptation despite high levels of gene flow in Sardinella lemuru (Bleeker, 1853) along the northern coast of Mindanao, Philippines
    Labrador, Kevin; Palermo, Joseph Dominic; Agmata, Altair; Ravago-Gotanco, Rachel; Pante, Ma. Josefa (Frontiers Media SA, 2022-02-24)
    Stock identification and delineation are important in the management and conservation of marine resources. These were highlighted as priority research areas for Bali sardinella (Sardinella lemuru) which is among the most commercially important fishery resources in the Philippines. Previous studies have already assessed the stocks of S. lemuru between Northern Mindanao Region (NMR) and Northern Zamboanga Peninsula (NZP), yielding conflicting results. Phenotypic variation suggests distinct stocks between the two regions, while mitochondrial DNA did not detect evidence of genetic differentiation for this high gene flow species. This paper tested the hypothesis of regional structuring using genome-wide single nucleotide polymorphisms (SNPs) acquired through restriction site-associated DNA sequencing (RADseq). We examined patterns of population genomic structure using a full panel of 3,573 loci, which was then partitioned into a neutral panel of 3,348 loci and an outlier panel of 31 loci. Similar inferences were obtained from the full and neutral panels, which were contrary to the inferences from the outlier panel. While the full and neutral panels suggested a panmictic population (global FST ∼ 0, p > 0.05), the outlier panel revealed genetic differentiation between the two regions (global FST = 0.161, p = 0.001; FCT = 0.263, p < 0.05). This indicated that while gene flow is apparent, selective forces due to environmental heterogeneity between the two regions play a role in maintaining adaptive variation. Annotation of the outlier loci returned five genes that were mostly involved in organismal development. Meanwhile, three unannotated loci had allele frequencies that correlated with sea surface temperature. Overall, our results provided support for local adaptation despite high levels of gene flow in S. lemuru. Management therefore should not only focus on demographic parameters (e.g., stock size and catch volume), but also consider the preservation of adaptive variation.
    We would like to acknowledge the assistance provided by Ma. Rio Naguit, Asuncion De Guzman, Jerry Garcia, Jhunrey Follante, Joshep Mercene, and John Christopher Azcarraga in sample collection and initial processing. We also acknowledge the research staff of the Marine Molecular Ecology and Evolution Laboratory (MMEEL), as well as the Marine Genomics and Molecular Genetics Laboratory (MGMGL) and its head, Arturo Lluisma, for providing valuable input in the conduct of the experiment and analysis of the data. Finally, we extend our gratitude to Demian Willette, Laura David, and Jonas Quilang for their valuable feedback on the manuscript.
  • Thumbnail Image
    Global mass spectrometric analysis reveals chemical diversity of secondary metabolites and 44-Methylgambierone production in Philippine Gambierdiscus strains
    Malto, Zabrina Bernice L.; Benico, Garry A.; Batucan, Jeremiah D.; Dela Cruz, James; Romero, Marc Lawrence J.; Azanza, Rhodora V.; Salvador-Reyes, Lilibeth A. (Frontiers Media SA, 2022-02-04)
    Surveillance and characterization of emerging marine toxins and toxigenic dinoflagellates are warranted to evaluate their associated health risks. Here, we report the occurrence of the ciguatera poisoning-causative dinoflagellate Gambierdiscus balechii in the Philippines. Toxin production and chemical diversity of secondary metabolites in G. balechii GtoxSAM092414, G. balechii Gtox112513, and the recently reported Gambierdiscus carpenteri Gam1BOL080513 were assessed using targeted and untargeted UPLC-MS/MS analysis and radioligand receptor-binding assay (RBA). 44-methylgambierone was produced by all three strains, albeitwith different levels based on RBA and UPLC-HRMS/MS analysis. The fatty acid composition was similar in all strains, while subtle differences in monosaccharide content were observed, related to the collection site rather than the species. Molecular networking using the GNPS database identified 45 clusters belonging to at least ten compound classes, with terpene glycosides, carbohydrate conjugates, polyketides, and macrolides as major convergence points. Species-specific peptides and polyhydroxylated compounds were identified in G. balechii GtoxSAM092414 and G. carpenteri Gam1BOL080513, respectively. These provide a glimpse of the uncharacterized biosynthetic potential of benthic dinoflagellates and highlight the intricate and prolific machinery for secondary metabolites production in these organisms.
    We would like to thank H. Junio and the Secondary Metabolites Profiling Laboratory of the Institute of Chemistry, University of the Philippines Diliman and K. B. Davis for assistance in the conduct of this study.