Latitudinal cline in the foraging dichotomy of loggerhead sea turtles reveals the importance of East China Sea for priority conservation

Special Issue: Biological traits, geographic distributions and species conservation in aquatic ecosystems[Aim]Quantifying the importance of habitat areas for conservation of highly migratory marine species with complex life histories can be challenging. For example loggerhead turtles (Caretta caretta) nesting in Japan forage both oceanically and neritically after their reproductive period. Here, we aimed to quantify the proportions of turtles using these two contrasting habitats (foraging dichotomy) to suggest priority conservation areas. [Location]North Pacific Ocean. [Methods]We examined the occurrence of foraging dichotomy at three nesting sites (Ishigaki, Okinoerabu Islands and Ichinomiya) based on stable isotope analysis of the egg yolks for 82 turtles and satellite tracking of post-nesting migration for 12 turtles. Moreover, we used the data of three other sites from previous studies (Yakushima Island, Minabe and Omaezaki). [Results]Two neritic foraging grounds (East China Sea and the coastal area of the Japanese archipelago), and an oceanic ground (North Pacific Ocean) were identified. We found a latitudinal cline with respect to the occurrence of foraging dichotomy; >84% of the females nesting at southern sites (Ishigaki and Okinoerabu Islands), 73% at middle sites (Yakushima Island and Minabe) and <46% at northern sites (Omaezaki and Ichinomiya) were neritic foragers; the proportion of oceanic foragers increased at northern sites. Based on the annual number of nests in the entire nesting region of Japan, satellite tracking and the latitudinal cline of foraging dichotomy, we estimated that 70% and 9% of annual nesting females in Japan utilize the neritic foraging habitat in the East China Sea and the coastal area of the Japanese archipelago, respectively, and that and 22% utilize the oceanic habitat of the North Pacific Ocean. [Main conclusions]The East China Sea represents a critical foraging habitat for the North Pacific populations of endangered loggerhead sea turtles. Our findings emphasize the need for international management to ensure their protection

Similarities and differences in metabolites of tongue cancer cells among two- and three-dimensional cultures and xenografts.

Metabolic programming of cancer cells is an essential step in transformation and tumor growth. We established two-dimensional (2D) monolayer and three-dimensional (3D) cultures, the latter called a "tissueoid cell culture system", using four types of tongue cancer cell lines. We also undertook a comprehensive metabolome analysis of three groups that included xenografts created by transplanting the cell lines into nude mice. In addition, we undertook a functional analysis of the mitochondria, which plays a key role in cancer metabolism. Principal component analysis revealed the plots of the four cell lines to be much narrower in 2D culture than in 3D culture and xenograft groups. Moreover, compared to xenografts, the 2D culture had significantly lower levels of most metabolites. These results suggest that the unique characteristics of each cell disappeared in 2D culture, and a type of metabolism unique to monolayer culture took over. Conversely, ATP production, biomass synthesis, and maintenance of redox balance were shown in 3D culture using sufficient nutrients, which closely resembled the metabolic activity in the xenografts. However, there were several differences between the metabolic activity in the 3D culture and xenografts. In vivo, the cancer tissue had blood flow with stromal cells present around the cancer cells. In the xenografts, we detected metabolized and degraded products in the liver and other organs of the host mice. Furthermore, the 3D system did not show impairment of mitochondrial function in the cancer cells, suggesting that cancer cells produce energy simultaneously through mitochondria, as well as aerobic glycolysis

Pyloric, pseudopyloric, and spasmolytic polypeptide-expressing metaplasias in autoimmune gastritis: a case series of 22 Japanese patients.

There are two types of pyloric gland-like metaplasia in the corpus of stomach: pyloric and pseudopyloric metaplasias. They show the same morphology as the original pyloric glands in H&E staining. Pseudopyloric metaplasia is positive for pepsinogen (PG) I immunohistochemically, whereas pyloric metaplasia is negative. Recently, spasmolytic polypeptide-expressing metaplasia (SPEM) is proposed for pyloric gland-like metaplasia mainly in animal experiments. SPEM expresses trefoil factor family 2 (TFF2) and is often considered synonymous with pseudopyloric metaplasia. We reviewed consecutive 22 Japanese patients with autoimmune gastritis (AIG) to investigate TFF2 expression in pyloric and pseudopyloric metaplasias by counting all pyloric gland-like glands in biopsy specimens taken from greater curvature of the middle corpus according to the Updated Sydney System. Pyloric metaplasia was seen in all the 22 cases, and pseudopyloric metaplasia was found in 15 cases. Of 1567 pyloric gland-like glands in all the cases, 1381 (88.1%) glands were pyloric metaplasia glands, and the remaining 186 (11.9%) glands were pseudopyloric metaplasia glands. TFF2 expression was observed in pyloric or pseudopyloric metaplasia glands in 20 cases. TFF2 expression was recognized in 409 of 1381 (26.9%) pyloric metaplasia glands and 27 of 186 (14.5%) pseudopyloric metaplasia glands (P<0.01, chi-square test). In conclusion, SPEM was not always the same as pseudopyloric metaplasia in human AIG, and the majority of metaplasia in AIG was not pseudopyloric but pyloric metaplasia

Using tsunami deposits to determine the maximum depth of benthic burrowing.

The maximum depth of sediment biomixing is directly related to the vertical extent of post-depositional environmental alteration in the sediment; consequently, it is important to determine the maximum burrowing depth. This study examined the maximum depth of bioturbation in a natural marine environment in Funakoshi Bay, northeastern Japan, using observations of bioturbation structures developed in an event layer (tsunami deposits of the 2011 Tohoku-Oki earthquake) and measurements of the radioactive cesium concentrations in this layer. The observations revealed that the depth of bioturbation (i.e., the thickness of the biomixing layer) ranged between 11 and 22 cm, and varied among the sampling sites. In contrast, the radioactive cesium concentrations showed that the processing of radioactive cesium in coastal environments may include other pathways in addition to bioturbation. The data also revealed the nature of the bioturbation by the heart urchin Echinocardium cordatum (Echinoidea: Loveniidae), which is one of the important ecosystem engineers in seafloor environments. The maximum burrowing depth of E. cordatum in Funakoshi Bay was 22 cm from the seafloor surface

Schematic representation of changes in sedimentary features in an area affected by the 2011 tsunami from before the tsunami to several years after the event.

<p>(A) The seafloor situation before the 2011 tsunami. The substrate was bioturbated. (B) Situation during the tsunami. The seafloor was eroded by the strong tsunami current. (C) Just after the 2011 tsunami. The seafloor is covered with tsunami deposits. The radiocesium (¹³⁴Cs and ¹³⁷Cs) released from the Fukushima Nuclear Accident was deposited on the seafloor surface. (D) Expected seafloor situation in the years following the 2011 tsunami. Bioturbated layer lacks physical sedimentary structures and carries the radiocesium due to vertical biomixing of the sediments following recolonization by benthic fauna. Layer 1: tsunami deposits, bioturbated after recolonization by benthic fauna after the event. Layer 2: unbioturbated tsunami deposits, showing well-defined physical sedimentary structures such as parallel laminations. Layer 3: pre-tsunami deposits.</p

Close-up view of the burrows produced by <i>Echinocardium cordatum</i>.

<p>(A) CT image of the upper part of core F-2. (B) Sketch of (A). The transverse width of the <i>E</i>. <i>cordatum</i> burrows is ~3 cm.</p

Map of the study area showing the locations of sampling sites.

<p>Map of the study area showing the locations of sampling sites.</p

Grain-size distributions, concentrations of ¹³⁷Cs, CT images, photographs, and columnar sections for the cores.

<p>Layer 1, the upper part of the cores, was bioturbated. Layer 2, the sediments between the base of Layer 1 and the erosional surface (the coarse-grained bed), shows well-defined physical sedimentary structures such as parallel laminations. Layer 3, the sediments beneath the erosional surface, show neither physical sedimentary structures nor obvious bioturbation structures. nd: not detected. m: mud. s: sand. g: gravel.</p

Temporal change in test width of <i>Echinocardium cordatum</i> in Funakoshi Bay before and after the 2011 tsunami.

<p>The <i>E</i>. <i>cordatum</i> population disappeared in 2011 and began to recolonize from early 2012. The test width had reached the same size as before the tsunami by September 2014, when the sediment cores were collected.</p