Rapid, contamination-less, and efficient environmental DNA filtration system.

Due to the sporadic distribution and trace amount of environmental DNA (eDNA) in deep-sea water, in the context of biodiversity monitoring, large volumes of filtration and multiple filtration replicates are required for eDNA metabarcoding. To address issues tied to the use of multiple filtration devices and large filtration volumes (e.g., contamination, time consumption, etc.), we have developed two systems for simple, rapid, and contamination-less filtration simultaneously that allow for the processing of multiple sample replicates from large volumes of water. First, the water from a Niskin bottle was filtered directly using a solenoid pump. Second, the pumped deep-sea water, using the siphon effect, was directly filtered by a filtration device driven by water pressure. This system can process 24 replicates simultaneously without the need for expensive equipment and active driving force. Compared with conventional filtering methods, e.g., peristaltic pumps, the proposed systems reduce filtration time, minimizing contamination, and enabling the simultaneous acquisition of multiple replicates. Overall, the systems presented here provide an effective approach for eDNA metabarcoding analysis, particularly for the filtration of large volumes of water containing small amounts of eDNA, such as deep-sea water. •The present systems reduce filtration time and contamination without water having to be transferred.•Simultaneous multiple replicates improve the efficiency and reliability of biodiversity assessments.

Preimplantation genetic testing using comprehensive genomic copy number analysis is beneficial for balanced translocation carriers.

Balanced chromosomal translocation is one of chromosomal variations. Carriers of balanced chromosomal translocations have an increased risk of spontaneous miscarriage. To avoid the risk, preimplantation genetic testing (PGT) using comprehensive genomic copy number analysis has been developed. This study aimed to verify whether and how embryos from couples in which one partner is a balanced translocation carrier have a higher ratio of chromosomal abnormalities. A total of 894 biopsied trophectoderms (TEs) were obtained from 130 couples in which one partner was a balanced translocation carrier (Robertsonian translocation, reciprocal translocation, or intrachromosomal inversion) and grouped as PGT-SR. Conversely, 3269 TEs from 697 couples who experienced recurrent implantation failure or recurrent pregnancy loss were included in the PGT-A group. The transferable blastocyst ratio was significantly lower in the PGT-SR group, even when bias related to the sample number and patient age was corrected. Subgroup analysis of the PGT-SR group revealed that the transferable blastocyst ratio was higher in the Robertsonian translocation group. Because the PGT-SR group had a higher proportion of untransferable embryos than the PGT-A group, PGT using comprehensive genomic copy number analysis was more beneficial for balanced translocation carriers than for infertility patients without chromosomal translocations. The frequencies of de novo aneuploidies were further analyzed, and the frequency in the PGT-SR group was lower than that in the PGT-A group. Therefore, we could not confirm the existence of interchromosomal effects in this study.

Evaluating the sampling effort for the metabarcoding-based detection of fish environmental DNA in the open ocean.

Clarifying the effect of the sampling protocol on the detection of environmental DNA (eDNA) is essential for appropriately designing biodiversity research. However, technical issues influencing eDNA detection in the open ocean, which consists of water masses with varying environmental conditions, have not been thoroughly investigated. This study evaluated the sampling effort for the metabarcoding-based detection of fish eDNA using replicate sampling with filters of different pore sizes (0.22 and 0.45 µm) in the subtropical and subarctic northwestern Pacific Ocean and Arctic Chukchi Sea. The asymptotic analysis predicted that the accumulation curves for detected taxa did not saturate in most cases, indicating that our sampling effort (7 or 8 replicates, corresponding to 10.5-40 L of filtration in total) was insufficient to fully assess the species diversity in the open ocean and that tens of replicates or a substantial filtration volume were required. The Jaccard dissimilarities between filtration replicates were comparable with those between the filter types at any site. In subtropical and subarctic sites, turnover dominated the dissimilarity, suggesting that the filter pore size had a negligible effect. In contrast, nestedness dominated the dissimilarity in the Chukchi Sea, implying that the 0.22 µm filter could collect a broader range of eDNA than the 0.45 µm filter. Therefore, the effect of filter selection on the collection of fish eDNA likely varies depending on the region. These findings highlight the highly stochastic nature of fish eDNA collection in the open ocean and the difficulty of standardizing the sampling protocol across various water masses.

Multidisciplinary Team Care Delays the Initiation of Renal Replacement Therapy in Diabetes: A Five-year Prospective, Single-center Study.

Objective Although recent reports have highlighted the benefits of multidisciplinary team care (MTC) for chronic kidney disease (CKD) in slowing the progress of renal insufficiency, its long-term effects have not been evaluated for patients with diabetes mellitus (DM). We compared the renal survival rate between MTC and conservative care (CC). Methods In this five-year, single-center, prospective, observational study, we examined 24 patients (mean age 65.5±12.1 years old, men/women 18/6) with DM-induced CKD stage ≥3 in an MTC clinic. The control group included 24 random patients with DM (mean age 61.0±12.8 years old, men/women 22/2) who received CC. MTC was provided by a nephrologist and medical staff, and CC was provided by a nephrologist. Results In total, 10 MTC and 20 CC patients experienced renal events [creatinine doubling, initiation of renal replacement therapy (RRT), or death due to end-stage CKD]. During the five-year observation period, there were significantly fewer renal events in the MTC group than in the CC group according to the cumulative incidence method (p=0.006). Compared to CC, MTC significantly reduced the need for urgent initiation of hemodialysis (relative risk reduction 0.79, 95% confidence interval [CI] 0.107-0.964). On a multivariate analysis, MTC (hazard ratio [HR], 0.434, 95% CI 0.200-0.939) and the slope of the estimated glomerular filtration rate during the first year (HR, 0.429 per 1 mL/min/m2/year, 95% CI 0.279-0.661) were negatively associated with renal events. Conclusion MTC for DM-induced CKD is an effective strategy for delaying RRT. Long-term MTC can demonstrate reno-protective effects.

Dispersion and settlement of two sympatric sculpins of the genus Gymnocanthus.

Larval dispersion rather than adult migration generally leads to the worldwide expansion of fishes. Species of the genus Gymnocanthus have expanded geographically while undergoing allopatric speciation. Of this genus, while Gymnocanthus tricuspis inhabits the Arctic Ocean and surrounding area, G. herzensteini and G. intermedius occur around northern Japan. Larval early life histories of G. herzensteini and G. intermedius from northern Japan and G. tricuspis from Unalaska Island were investigated to estimate their dispersal potential during larval stages. The larval and juvenile abundances of G. herzensteini and G. intermedius were highest in May in shallow sandy bottoms below 7 m in depth, and the body sizes were 9.7-34.6 mm notochord length (NL) and/or standard length (SL) in G. herzensteini and 8.4-46.7 mm NL and/or SL in G. intermedius. Two egg masses of G. tricuspis (1.92 ± 0.08 mm in diameter) and hatched larvae (6.20 ± 0.19 mm NL) were collected in March. Compared with other sculpins in previous studies, the body sizes of G. herzensteini and G. intermedius at hatch are large and at settlement are small, while both hatch and settlement sizes of G. tricuspis are much larger. Counting micro-increments between the hatch check and settlement marks in G. herzensteini and G. intermedius demonstrated that the pelagic larval durations for 2 weeks with an immature body suggests that these species cannot disperse widely during the pelagic phase, while pelagic larvae of Arctic species such as G. tricuspis with long pelagic larval durations could disperse.

Freeze Tolerance in Sculpins (Pisces; Cottoidea) Inhabiting North Pacific and Arctic Oceans: Antifreeze Activity and Gene Sequences of the Antifreeze Protein.

Many marine species inhabiting icy seawater produce antifreeze proteins (AFPs) to prevent their body fluids from freezing. The sculpin species of the superfamily Cottoidea are widely found from the Arctic to southern hemisphere, some of which are known to express AFP. Here we clarified DNA sequence encoding type I AFP for 3 species of 2 families (Cottidae and Agonidae) belonging to Cottoidea. We also examined antifreeze activity for 3 families and 32 species of Cottoidea (Cottidae, Agonidae, and Rhamphocottidae). These fishes were collected in 2013⁻2015 from the Arctic Ocean, Alaska, Japan. We could identify 8 distinct DNA sequences exhibiting a high similarity to those reported for Myoxocephalus species, suggesting that Cottidae and Agonidae share the same DNA sequence encoding type I AFP. Among the 3 families, Rhamphocottidae that experience a warm current did not show antifreeze activity. The species inhabiting the Arctic Ocean and Northern Japan that often covered with ice floe showed high activity, while those inhabiting Alaska, Southern Japan with a warm current showed low/no activity. These results suggest that Cottoidea acquires type I AFP gene before dividing into Cottidae and Agonidae, and have adapted to each location with optimal antifreeze activity level.

Origins of two hemiclonal hybrids among three Hexagrammos species (Teleostei: Hexagrammidae): genetic diversification through host switching.

Two natural, hemiclonal hybrid strains were discovered in three Hexagrammos species. The natural hybrids, all of which were females that produced haploid eggs containing only the Hexagrammos octogrammus genome (maternal ancestor; hereafter Hoc), generated F1 hybrid-type offspring by fertilization with haploid sperm of Hexagrammos agrammus or Hexagrammos otakii (paternal species; Hag and Hot, respectively). This study was performed to clarify the extent of diversification between the two hybrids and the maternal ancestor. Genealogical analysis using mtDNA revealed that all 38 Hoc/Hot hybrids formed a branch (Branch I) with 18 of the 33 Hoc/Hag hybrids. No haplotype sharing was observed with the maternal ancestor. Further, microsatellite DNA analysis suggested that the members of Branch I shared the same hemiclonal genome set. The results suggested that Hoc/Hot hybrids originated by anomalous hybridization, or "host switching," between Hoc/Hag and Hot, and not from interspecific hybridization between Hoc and Hot. The remaining 9 of 11 Hoc/Hag haplotypes and all of the 27 Hoc haplotypes were mixed within the genealogical tree, as if they had originated from multiple mutations. However, Hoc/Hag could also mate with Hoc. Although offspring from this host switch (Backcross-Hoc) have the same genome as normal Hoc, a part of their genome retains genetic factors capable of producing hemiclones. Consequently, when a descendant of a BC-Hoc hybrid mates with Hag males, a new hemiclone lineage will arise. Multiple haplotype revival through host switching from a single mutation in hybrids is another possible hypothesis for the observed mixing of Hoc/Hag haplotypes within the mtDNA genealogical tree.