Genome-wide SNP genotyping reveals hidden population structure of an acroporid species at a subtropical coral island: Implications for coral restoration

1. It is essential to consider genetic composition for both conventional coral restoration management and for initiating new interventions to counter the significant global decline in living corals. Population genetic structure at a fine spatial scale should be carefully evaluated before implementing strategies to achieve self-sustaining ecosystems via coral restoration.
2. This study investigated the population genetic structure of two acroporid species at Kume Island, Okinawa, Japan. There were 140 colonies of Acropora digitifera collected from seven study sites, and 81 colonies of Acropora tenuis from six sites. In total, 384 single nucleotide polymorphism (SNP) loci for A. digitifera and 470 SNPs for A. tenuis were obtained using a comparatively economical technique, Multiplexed ISSR Genotyping by sequencing.
3. Observed heterozygosity was significantly lower than expected heterozygosity at all SNP sites in both acroporid species, suggesting deficient genetic diversity possibly caused by past massive coral bleaching. Even though both species are broadcast spawners, the population structure was different in the two species. No detectable structure was evident in A. digitifera, but two distinct clades were found in A. tenuis. The genetic homogeneity of A. digitifera at Kume Island suggests that this species could be used as a focal species for active restoration in terms of genetic differentiation at this island. By contrast, A. tenuis unexpectedly included two distinct clades with little or no admixture within a small study area, possibly representing two reproductively isolated cryptic species. Thus, when using A. tenuis, it would be prudent to avoid disturbing the genetic composition of wild populations until this question is answered.

     

A plastidic glucose-6-phosphate dehydrogenase is responsible for hypersensitive response cell death and reactive oxygen species production

Glucose-6-phosphate dehydrogenase (G6PDH) has been implicated in the supply of reduced nicotine amide cofactors for resistance to biotic and abiotic stresses. Here, we show participation of the plastidic P2 isoform of G6PDH in plant immunity. A cytosolic isoform (NbG6PDH-Cyto) and two plastidic isoforms (NbG6PDH-P1 and NbG6PDH-P2) cloned from Nicotiana benthamiana were localized in cytosol and chloroplasts, respectively. Hypersensitive response (HR) cell death and NADPH oxidase (RBOH; respiratory burst oxidase homolog)-dependent reactive oxygen species (ROS) production after recognition of INF1 elicitin, secreted by oomycete Phytophthora infestans, decreased in NbG6PDH-P2-silenced plants, but not in NbG6PDH-Cyto- and NbG6PDH-P1-silenced plants. Silencing of the cytosolic NAD kinase NbNADK1, which phosphorylates NADH to form NADPH, compromised HR cell death and ROS production, and concomitant silencing with NbG6PDH-P2 reduced HR cell death and ROS to levels near those in NbG6PDH-P2-silenced plants. Similarly, silencing NbG6PDH-P2 and NbNADK1 resulted in high susceptibility to P. infestans. These results suggest that NADPH produced by the P2 isoform of G6PDH in chloroplasts is responsible for HR cell death and ROS production mediated by RBOH and that NbNADK1 is involved in this pathway.     

Evaluation of serum and urine 1,5-anhydro-D-glucitol and myo-inositol concentrations in healthy dogs

1,5-anhydro-D-glucitol (1,5AG) is a pyranoid polyol compound found in human circulating blood. Myo-inositol (MI) is a stereoisomer of inositol and serves as a precursor of inositol phospholipids. 1,5AG and MI are filtered by the glomerulus and almost completely reabsorbed through the renal tubules. However, under hyperglycemic conditions, reabsorption through the renal tubules is competitively inhibited because the structures of 1,5AG and MI resemble that of glucose. In this study, we investigated the kinetics of serum and urine 1,5AG and MI levels in healthy dogs. We demonstrated that 1,5AG and MI exist in canine serum and urine by gas chromatography-mass spectrometry. Under continuous hyperglycemic conditions, the serum 1,5AG concentration in healthy dogs decreased while the serum MI concentration remained unchanged. Urinary excretion of 1,5AG and MI increased significantly after blood glucose concentrations reached 200 to 220 mg/dl. A significant negative correlation was observed between serum 1,5AG and glucose concentrations during hyperglycemia. However, no significant correlation was observed between serum MI and glucose concentrations. In this study, we demonstrated that serum and urine 1,5AG and MI levels were changed by blood glucose concentrations. The serum 1,5AG concentration was decreased by continuous hyperglycemia. However, the serum MI concentration does not reflect hyperglycemia.     

Patient-side assay of lipase activity correlating with pancreatic lipase immunoreactivity in the dog

Pancreatitis is a common exocrine pancreatic disease in dogs, and the pancreatic lipase immunoreactivity (PLI) test is used for diagnosis. Enzyme catalytic assay is thought to have low specificity, but a lipase activity assay with increased specificity has been developed in human clinical chemistry. We measured serum lipase activity of 65 client-owned dogs using the newly developed FUJI DRI-CHEM slide and compared the results with their PLI concentrations. The results showed a good correlation (r = 0.91), and the normal and pancreatitis dogs identified based on the PLI values were correctly separated based on lipase activity. The present study suggests that FUJI DRI-CHEM lipase activity would be helpful for diagnosis of pacreatitis in dogs and, in particular, that it can be used as a patient-side assay and contributes to immediate treatment.     

In vitro and in vivo comparison of applanation tonometry and rebound tonometry in dogs

Intraocular pressure (IOP) evaluated by applanation tonometry via TONO-PEN XL (TP), and rebound tonometry via TonoVet (TV) were compared in enucleated canine eyes with varied pressure of the anterior chamber (AC) and in clinical cases. TV measured IOP values were lower than IOP measurements of TP in the enucleated eyes with 5-10 mmHg of AC (P<0.0001), though there was no significant difference in IOP values obtained with TP and TV on the pressure ranges of 15-20 mmHg. However, TP detected IOP values were lower than IOP measurements of TV in the eyes with over 25 mmHg of AC (P<0.0001). The results of clinical cases were similar to the enucleated eye model. There was no significant difference in IOP values obtained from TP and TV in dogs with normotensive eyes. IOP measurements of TP were lower than those of TV in glaucomatous eyes (P<0.0001). TV was a reliable tonometer for measurement of IOP in hypertensive eyes, whereas it was less accurate than TP in hypotensive eyes. The characteristics of TP and TV should be considered in the evaluation of IOP in practice.     

Inheritance of the Robertsonian translocation (1/21) in the Holstein-Friesian cattle. I. Chromosome analysis

A new type of Robertsonian translocation (1/21) was found in Holstein-Friesian breed, and transmitted through the three generations, namely from the bull to 6 out of 11 daughters and 4 out of 7 grand-daughters/sons. Although the father of the bull was not available for cytogenetical studies, it was ascertained that 5 half-sibs of the bull had a normal karyotype. By C-banded karyotypes, the 9 translocation carriers within the three generations had a dicentric centromere in the translocated chromosome. It seems that no morphological effects have been noted to be associated with the translocation in all cases.