Biology subjects

Kaneko, G.

Publications and source records attributed to Kaneko, G..

3 recordsLinked to original sources

bioRxiv2023

DNA barcoding revealed a high percentage of mislabeling in commercial fish products: the first empirical survey in South Texas

Seafood mislabeling is a widespread problem that have produced a growing distrust of seafood industry. In this study, we examined the prevalence of mislabeling in fish samples from regional markets in the greater Houston area and close-by coastal communities. A total of 63 fish fillet samples were purchased, labeled, and stored at -20{degrees}C in individual packages until DNA extraction. DNA fragments of roughly 700 base pairs encoding cytochrome oxidase I (COI) were PCR-amplified from each DNA sample. With 99.6-100% nucleotide identity in the GenBank and BOLD databases, all samples were correctly identified at the species level. The scientific names identified by DNA barcoding were matched with legally acceptable market names using the US Food and Drug Administration (FDA) Seafood List. Out of the 63 samples examined, 13 samples (20.6%) were mislabeled. Moreover, 24 samples (38.1%) did not use the acceptable market names, indicating that the FDA policy is poorly implemented in seafood industry. The first DNA barcoding survey this area warranted the need of continuous monitoring and the dissemination of the regulation combined with taxonomic knowledge.

molecular biology↗

bioRxiv2022

Genomic loss of the HSP70cA gene in the vertebrate lineage

Metazoan 70 kDa heat shock protein (HSP70) genes have been classified into four lineages: cytosolic A (HSP70cA), cytosolic B (HSP70cB), endoplasmic reticulum (HSP70er), and mitochondria (HSP70m). Because previous studies have identified no HSP70cA genes in vertebrates, we hypothesized that this gene has lost on the evolutionary path to vertebrates. To test this hypothesis, the present study conducted a comprehensive database search followed by phylogenetic and synteny analyses. The HSP70cA gene was present in invertebrates and animals that belong to subphyla of Chordata, Cephalochordata (lancelets) and Tunicata (tunicates). However, the genomes of early vertebrates in the subphylum Craniata (lamprey, hagfish, elephant shark, and coelacanth) contained only HSP70cB genes, suggesting the loss of the HSP70cA gene in the early period of vertebrate evolution. Synteny analysis using available genomic resources indicated that the synteny around the HSP70 genes was generally conserved between tunicates, but it was largely different between tunicates and lamprey. These results suggest the presence of dynamic chromosomal rearrangement in early vertebrates, which possibly caused the loss of the HSP70cA gene in the vertebrate lineage.

evolutionary biology↗

bioRxiv2020

The complex evolution of the HSP70 gene family

The metazoan 70-kDa heat shock protein (HSP70) family contains several members localized in different subcellular compartments. The cytosolic members have been classified into inducible HSP70s and constitutive heat shock cognates (HSC70s), but their distinction and evolutionary relationship remain unclear because of occasional reports of "constitutive HSP70s" and the lack of cross-phylum comparisons. Here we provide novel insights into the evolution of these important molecular chaperones. Phylogenetic analyses of [~]100 full-length HSP70s revealed an ancient duplication that gave rise to two lineages from which all metazoan cytosolic HSP70s descend. One lineage (A) contains a relatively small number of Lophotrochozoan and Ecdysozoan genes, none of which have been shown to be constitutively expressed (i.e., either inducible or unknown). The other lineage (B) included both inducible and constitutive genes from diverse phyla. Species-specific duplications are present in both lineages, and Lineage B contains well-supported phylum-specific clades for Rotifera, Nematoda, and Chordata. Some genes in Lineage B have likely independently acquired inducibility, which may explain the sporadic distribution of "HSP70" or "HSC70" in previous analyses. Consistent with the diversification history within each group, inducible members show lower purifying selection pressure compared to constitutive members. These results illustrate the evolutionary history of the HSP70 family, encouraging us to propose a new nomenclature: "HSP70 + subcellular localization + linage + copy number in the organism + inducible or constitutive, if known." e.g., HSP70cA1i for cytosolic Lineage A, copy 1, inducible.

evolutionary biology↗