Erythrocyte Nuclei Research Articles

ANALYSIS OF THE INTERRELATION OF CYTOGENETIC HOMEOSTASIS AND OXIDATIVE STRESS IN THE ORGANISM OF GOBY FISH (GOBIIDAE) OF THE NORTHERN CASPIAN

Aim. The aim is to investigate the relationship between the content of micronuclei, destructive disorders in the nuclei of erythrocytes of peripheral blood of the goby fish and intensity of lipid peroxidation in fish tissues. Methods. Was used the method of quantitative accounting of morphologically altered red blood cells of peripheral blood of goby fish. Evaluation of cytogenetic disorders in fish blood cells was carried out based on a micronucleus test. Samples of muscle tissues and liver were sampled for biochemical analyzes. The rates of lipid peroxidation (LPO level) were determined by a method based on the reaction of malondialdehyde and thiobarbituric acid, the end product of lipid peroxidation. Results. A correlation was found between the rates of spontaneous LPO, ascorbate-dependant LPO and the accumulation of malondialdehyde in the liver of fish and changes in the nucleus of erythrocytes (R2 =0,8; R2 =0,6; R2 =0,7, respectively). Conclusions. We established the functional dependence which justifies the need to use cytogenetic markers to assess the impact of adverse environmental factors on the body of hydrobionts.

Measurements of three-dimensional refractive index tomography and membrane deformability of live erythrocytes from Pelophylax nigromaculatus

Unlike mammalian erythrocytes, amphibian erythrocytes have distinct morphological features including large cell sizes and the presence of nuclei. The sizes of the cytoplasm and nuclei of erythrocytes vary significantly over different species, their environments, or pathophysiology, which makes hematological studies important for investigating amphibian species. Here, we present a label-free three-dimensional optical quantification of individual amphibian erythrocytes from frogs Pelophylax nigromaculatus (Rana nigromaculata). Using optical diffraction tomography, we measured three-dimensional refractive index (RI) tomograms of the cells, which clearly distinguished the cytoplasm and nuclei of the erythrocytes. From the measured RI tomograms, we extracted the relevant biochemical parameters of the cells, including hemoglobin contents and hemoglobin concentrations. Furthermore, we measured dynamic membrane fluctuations and investigated the mechanical properties of the cell membrane. From the statistical and correlative analysis of these retrieved parameters, we investigated interspecific differences between frogs and previously studied mammals.

Ultracytochemical visualization of calcium distribution in heart cells and erythrocytes of zebrafish Danio rerio

Detection of patterns of subcellular calcium distribution in the cardiovascular system can contribute to understanding its role in cardiac and blood function. The present study localized calcium in heart atrium, ventricle, and bulbus arteriosus as well as in erythrocytes of zebrafish Danio rerio using an oxalate-pyroantimonate technique combined with transmission electron microscopy. Intracellular calcium stores were detected in caveolae, mitochondria, and the nuclei of several zebrafish cardiac cell types. Melanin pigmentation containing calcium stores was detected in the pericardial cavity. Melanin might be an extracellular source of calcium for heart beating and/or a lubricant to prevent friction during beating process. Calcium deposits were also detected in the plasma membrane, cytoplasm and nucleus of erythrocytes as well as in blood plasma. Possible exchange of calcium between erythrocytes and blood plasma was observed. Interactions of such calcium stores and possible contribution of extracellular calcium stores such as melanin pigmentation to supply calcium for vital functions of heart cells should be addressed in future studies.

HIGH RESISTANCE OF CHICKEN EMBRYO RED BLOOD CELLS TO ACID ACTION

In this paper, the results of the comparative studies of the resistance of Gallus gallus chicken embryo and human erythrocytes are presented to acid action.MethodsRed blood cells from decapitated 10–12 day‐old chicken embryos (5±0.6 g) and human donor blood were used in the experiments. The cells were isolated by centrifugation and washed three times with 145 μmol/l NaCl solution. The hemolysis was performed using: a) Mcllvein buffer solution (MBS) (0.31 g/l Na2HPO4 and 1.87 g/l citric acid, pH = 2.5); b) 0.1 N HCl. The optical density (D) was registered by using photocolorimeter at λ=540 nm. The part of the experiments was made by using isotonic 145 μmol/l choline chloride solution. The experiments were carried out at 18–20°C; the reliability of the differences was evaluated with the Van der Waerden test.ResultsThe hemolytic resistance of the chick embryo erythrocytes was higher than of human erythrocytes. The lag phase value, the time to 50% hemolysis (t50) and the time to complete hemolysis increased twice (p<0.05). The D value remained high after the completion of hemolysis. We believe that the effect of acid on the erythrocyte nucleus led to the decondensation and swelling of chromatin, causing an increase in optical density. The replacement of NaCl with choline chloride did not affect the resistance of human erythrocytes and led to an increase in the chick embryo resistance (p<0.05). In particular, the hemolytic start time (t0) and the end time (tend) were increased by 16% (p <0.05) and 21% (p <0.05) respectively. The results of these experiments showed that Na+/H+ exchange couldn't lead to an increase in the acid resistance of chick embryo erythrocytes. The calculations indicated that at the anion exchanger density of 2760 copies/μm2 and 8,300 copies/μm2 in chicken and human erythrocytes, respectively. The amount of anion exchangers was 1.2 × 106 copies per human erythrocyte and 6.3 × 105 copies per chick embryo erythrocyte. This is a in good agreement with the 2‐fold increased resistance of the chicken embryo erythrocytes compared to the human erythrocytes.Thus, the high resistance of chicken erythrocytes in comparison with human erythrocytes can be associated with a lower density of anion exchangers in the chicken red blood cells membrane.Support or Funding InformationThe study was supported by project № AAAA‐A17‐117012310152‐2This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Ploidy level and their relationship with vegetative traits of mulberry ( Morus spp.) species in Taiwan

Abstract To accelerate the mulberry breeding program and examine the genome size and ploidy levels of 27 mulberry accessions of promising lines in Taiwan, nuclei suspensions were prepared from unfolded young leaves and analyzed by a flow cytometer. The genome size of each accession was estimated by referring to the standard genome size of chicken erythrocyte nuclei (CEN, 2.5 pg). Our results indicated that 25 among 27 investigated accessions in M. bombycis, M. alba, M. latifolia, M. australis, M. formosnensis, and M. atropurpurea are diploids with genome sizes ranging from 0.61 to 0.71 pg. ‘Elongated mulberry No. 1’ (M. laevigata) with a genome size of 1.06 pg is a triploid. Two populations were identified in the accession ‘67C001’ (M. australis Poir.) with a genome size of either 0.63 pg or 0.98 pg. Due to their similarity in appearance, we suspected that they are probably from the same origin, thus warranting further investigations. Several important vegetative characters of diploids and triploids have been estimated, including leaf length, leaf width, petiole length, petiole width, leaf thickness, and internode length, to document their correlation using the unpaired t-test. Subsequently, the statistical relationship between diploid and triploid species on some of these important characters, including leaf width, petiole width and internode length, was determined through binary regression analysis. We suggested that the internode length could provide a beneficial index to distinguish individuals with different ploidy levels in the field. Results of this study provide useful information to clarify the taxonomy of Morus and improve breeding programs aiming to advance horticulture and sericulture.

Concerted evolution of body mass and cell size: similar patterns among species of birds (Galliformes) and mammals (Rodentia).

ABSTRACTCell size plays a role in body size evolution and environmental adaptations. Addressing these roles, we studied body mass and cell size in Galliformes birds and Rodentia mammals, and collected published data on their genome sizes. In birds, we measured erythrocyte nuclei and basal metabolic rates (BMRs). In birds and mammals, larger species consistently evolved larger cells for five cell types (erythrocytes, enterocytes, chondrocytes, skin epithelial cells, and kidney proximal tubule cells) and evolved smaller hepatocytes. We found no evidence that cell size differences originated through genome size changes. We conclude that the organism-wide coordination of cell size changes might be an evolutionarily conservative characteristic, and the convergent evolutionary body size and cell size changes in Galliformes and Rodentia suggest the adaptive significance of cell size. Recent theory predicts that species evolving larger cells waste less energy on tissue maintenance but have reduced capacities to deliver oxygen to mitochondria and metabolize resources. Indeed, birds with larger size of the abovementioned cell types and smaller hepatocytes have evolved lower mass-specific BMRs. We propose that the inconsistent pattern in hepatocytes derives from the efficient delivery system to hepatocytes, combined with their intense involvement in supracellular function and anabolic activity.

Effects of abamectin on bullfrog tadpoles: insights on cytotoxicity.

Abamectin is one of the most used pesticides worldwide. However, investigations about its effects on amphibian populations are rare. Thus, the present study sought to investigate possible cytotoxic effects on Lithobates catesbeianus tadpoles exposed to low abamectin concentrations diluted in water. Accordingly, four experimental groups were set: negative control, positive control (cyclophosphamide-40mLL-1), abamectin at concentrations 36μga.i./L (ABA36 group), and 72μga.i./L (ABA72 group), applied as Kraft® 36EC. The micronucleus test was conducted and other nuclear abnormalities in peripheral blood erythrocytes were checked after 24, 48, and 72h of exposure to the treatments. The total of other nuclear abnormalities was influenced by the treatments, whereas the frequency of micronuclei was influenced by the exposure time. Such frequency was higher in the animals comprising the ABA72 group, which was assessed 72h after the exposure had begun. The total of other nuclear abnormalities was influenced by the treatments. Animals in the positive control, ABA36, and ABA72 groups showed similar frequency of these abnormalities at 48 and 72h. However, this frequency was statistically higher than that of animals in their respective negative control groups. Thus, the present study confirmed the hypothesis that the exposure of L. catesbeianus tadpoles to abamectin caused cytotoxic effects on them, although this exposure lasted short and the concentrations were low. It disclosed prospects for variations in the nucleus of erythrocytes circulating in amphibians, a fact that may provide an important/complementary approach for the detection of cytotoxicity caused by abamectin exposure.

New Haemoproteus parasite of parrots, with remarks on the virulence of haemoproteids in naive avian hosts

Haemoproteus infections can cause fatal disease in parrots (Psittaciformes), one of the most endangered groups of birds. The great diversity of parrots in tropical and subtropical ecosystems has been markedly understudied in terms of their parasite diversity. Only two psittacine Haemoproteus species have been described. Here we report a new Haemoproteus parasite, H. (Parahaemoproteus) homohandai n. sp. (lineage hARCHL01) found in erythrocytes of a Red-and-green macaw Ara chloropterus. We morphologically and genetically characterize the parasite based on a segment of the mitochondrial cytochrome b gene, which can be used for identification and diagnosis of infection. This is the first Haemoproteus species described from South American parrots and the first genetically characterized psittacine Haemoproteus sp. Haemoproteus homohandai n. sp. can be readily distinguished from other haemoproteids by its growing circumnuclear and close to circumnuclear macrogametocytes, which are strictly associated with erythrocyte nuclei, but do not touch the erythrocyte envelope along their entire margin and do not fill erythrocytes up to their poles. Illustrations of growing and mature gametocytes of the new species are given, and a phylogenetic analysis identifies the position of this parasite lineage in relation to other Haemoproteus parasites. Importantly, H. homohandai n. sp. and all other Haemoproteus lineages reported from parrots cluster with species of the subgenus Parahaemoproteus, indicating the transmission by Culicoides biting midges.

Additive scaling law for structural organization of chromatin in chicken erythrocyte nuclei.

Small-angle neutron scattering (SANS) on nuclei of chicken erythrocytes demonstrates the cubic dependence of the scattering intensity Q^{-3} in the range of momentum transfer Q∈10^{-3}-10^{-2}nm^{-1}. Independent spin-echo SANS measurements give the spin-echo function, which is well described by the exponential law in a range of sizes (3×10^{2})-(3×10^{4}) nm. Both experimental dependences reflect the nature of the structural organization of chromatin in the nucleus of a living cell, which corresponds to the correlation function γ(r)=ln(ξ/r) for r<ξ, where ξ=(3.69±0.07)×10^{3} nm, the size of the nucleus. It has the specific scaling property of the logarithmic fractal γ(r/a)=γ(r)+ln(a), i.e., the scaling down by a gives an additive constant to the correlation function, which distinguishes it from the mass fractal, which is characterized by multiplicative constant.

ЭКОЛОГИЧЕСКАЯ И ЦИТОГЕНЕТИЧЕСКАЯ ХАРАКТЕРИСТИКА СТРУКТУРЫ ПОПУЛЯЦИИ СЕРЕБРЯНОГО КАРАСЯ (CARASSIUS AURATUSGIBELIO, BLOCH, 1782) ОЗЕРА СЕВАН (АРМЕНИЯ)

The article studies the morphological characteristics, age, sex structure, fecundity and cytomorphological parameters of erythrocytes of Crucian carp ( Carassius auratus gibelio , Bloch, 1782) from both subwatersheds (Big and Small) of Lake Sevan. The analysis of cyto-morphological characteristics of nuclei and erythrocytes showed that the population of the Crucian carp from the lake is heterogeneous as a whole, and consists of individuals with small (diploid) and large nuclei and erythrocytes (subgroups I and II). In sampling taken from both subwatersheds of Lake Sevan occurrence of individuals with the smallest nuclei (diploid individuals) made 38.8%. Crucian carps with the largest nuclei of red blood cells (subgroup II) are noted among females more than among males, with a low percentage of occurrences - 17.5%. The ratios of the volumes of the nuclei of erythrocytes and the number of nucleoli in the nuclei of erythrocytes of Crucian carps can be indicating the existence of triploid individuals in Lake Sevan. The number of Crucian carps with the largest nuclei of red blood cells (subgroup II, possibly triploids) is 17.5% in both subwatersheds of Lake Sevan. During the spawning period males prevailed to females in Small Sevan (1.5 ♂:1 ♀) and females prevailed to males in Big Sevan (1 ♂:1.6 ♀), which is the result of different spawning conditions in different parts of the lake. The highest role in the catch had individuals at the age of 3+. It has been established that the Crucian carp from Lake Sevan with large nuclei of erythrocytes do not differ statistically from individuals with small nuclei for all studied plastic and meristic characteristics and absolute individual fecundity.

Spin-echo small-angle neutron scattering study of the structure organization of the chromatin in biological cell

Spin-echo small-angle scattering (SESANS) technique is a method to measure the structure of materials from nano- to micrmeter length scales. This method could be important for studying the packaging of DNA in the eukaryotic cell. We measured the SESANS function from chicken erythrocyte nuclei which is well fitted by the exponential function G(z) = exp(−z/ξ), where ξ is the correlation length of a nucleus (in experimental data ξ = 3, 3 μm). The exponential decay of G(z) corresponds to the logarithmic pair correlation function γ(r) = ln(ξ/r). As the sensitivity of the SESANS signal depends on the neutron wavelength, we propose the SESANS setup with the changeable wavelength in the range from 2 to 12 Å. Such option allows one to study in great detail the internal structure of the biological cell in the length scale from 10−2μm to 10 μm.

A pioneering study on cytotoxicity in Australian parakeets (Melopsittacus undulates) exposed to tannery effluent

Waste effluent from the tannery industry is a major source of environmental pollution. Considering that the bird intake of water contaminated with tannery effluent constitutes a potential genotoxic source, especially for birds inhabiting areas closest to tanning industries, the aim of this study is to assess the possible mutagenic effects that the intake may have on Melopsittacus undulatus (Australian parakeet). In order to do so, adult male and female M. undulatus were distributed in two experimental groups: control (drinking water) and TE (5%). After 60 days of exposure, the micronucleus test, as well as tests looking for other nuclear abnormalities in the peripheral blood of the birds were performed. The male and female birds exposed to the pollutant have presented the highest total number of nuclear abnormalities, as well as increased individual abnormalities such as nuclei with symmetrical constricted bi-lobed/bi-nucleated erythrocytes, indented nuclei and micro-lobed nuclei (top)/micro-nuclei (bottom). In addition, the exposure to TE has caused a nuclear variant increase rarely reported in the literature concerning poultry erythrocyte nuclei. The birds exposed to the pollutant have presented the highest frequency of displaced nuclei forming different rotation/displacement angles within the cells. Therefore, the current study confirmed the toxicological potential of TE and was pioneer in showing that male and female M. undulatus exposed to pollutant present the highest frequency of erythrocyte nuclear abnormalities, thus corroborating the initial hypothesis herein presented.

Buparvaquone therapy in a rock pigeon infected with Haemoproteus columbae showing torticollis.

A clinical Haemoproteus columbae infection in a twomonths rock pigeon was diagnosed on the basis of outward signs and blood smear examination. The clinical signs suggestive of pigeon malaria were anorexia, depression, inability to fly, circling movements and episodes of torticollis. The characteristic halter shaped gametocytes were seen, in thin blood smear, encircling the nucleus of erythrocytes. Buparvaquone therapy, two intramuscular injections at the rate of 5mg/kg at 72h interval, was successful. Supplementation of multivitamin helped in speedy recovery and clinical signs along with uncommon torticollis, completely disappeared in oneweek.

Morphofunctional peculiarities of erythrocytes in wild and farmed Coregonid fishes from Lake Baikal

Structure and cytometric indices of red blood cells (RBC) and hemoglobin content (Hb) and oxygen capacity of the blood (OCB) of omul, whitefish, and hybrids thereof captured in Lake Baikal (wild) and incubated and grown in a freshwater aquarium complex (FAC) (farmed) have been analyzed. Cytometric parameters of red blood cells of wild omul, whitefish, and hybrids thereof exceed those of the cells of fish reared in aquariums under identical conditions. The effect of aquarium rearing on the shape of red blood cells is the least pronounced in Siberian whitefish and F1 progeny of Siberian whitefish females and omul males (f Sw x m Om). The erythrocyte size in hybrids of female Lacustrine whitefish and male omul (f Lw x m Om) is determined by the size of these cells in female parents, since female Lacustrine whitefish have the largest erythrocytes. Cytometric parameters of erythrocytes of all Coregonid fishes investigated are higher in fish reared in warm aquaria than in conspecifics reared in aquaria with cold water. Erythrocyte nuclei are smaller in artificially propagated hybrids than in parent fish captured in the wild or in whitefish and omul reared in aquaria under the same conditions. A distinct pool of erythrocytes from whitefish captured in the wild have a 20–30% higher content of functionally active mitochondria than erythrocytes of whitefish reared in aquaria; a disrupted mitochondrial structure is also observed in erythrocytes from the latter population of fish. The results show that distinctive features of metabolism related to oxygen transport in the Baikal coregonid fish that were investigated are determined by adaptation to the conditions of the ecological niches occupied by the fish.

Reference micrometrical values of blood cells of Emu (Dromaius novaehollandiae)

The present study was undertaken with the objective of determining the micrometrical values of blood cells of 8 normal and healthy adult Emu birds (>1 year of age), maintained under optimum conditions of feed and management at a private Poultry Farm, Anand. Mean, standard error and the range of all the micrometric values of the various blood cells of Emu are obtained. Total Erythrocyte Count (TEC), Total Leucocyte count (TLC), Thrombocyte count and Differential leucocyte count (DLC) were also determined. The mean±SE (range) of the length (μm) and the width (μm) of erythrocyte were 13.2±0.21 (12.8–14.4) and 6.45±0.24 (5.33–6.93). The mean±SE (Range) of the length and the width of nucleus of erythrocyte were 6.08±0.21 (4.8–6.4) and 2.96±0.12 (2.4–3.2), respectively. The mean±SE (range) of diameter (μm) of the heterophils were 10.78±0.43 (12.8–8.8), eosinophils were10.46±0.25 (11.2–9.6), basophils were 8.96±0.26 (8–9.6), small lymphocyte were 5.44±0.23 (4.8–6.4), large lymphocyte were 8.92±0.33 (7.6–10.4) and monocytes were 13.34±0.54 (11–16). The mean±SE (range) of the length (μm) and the width (μm) of thrombocytes were 5.6±0.26 (4.8–6.4) and 4.64±0.37 (3.2–6.4). This can serves as baseline for the future research on the micrometrical and morphological studies on the blood cells of emu.

A novel and easy FxCycle™ violet based flow cytometric method for simultaneous assessment of DNA ploidy and six-color immunophenotyping.

Abnormal DNA ploidy is a valuable prognostic factor in many neoplasms, especially in hematological neoplasms like B-cell acute lymphoblastic leukemia (B-ALL) and multiple myeloma (MM). Current methods of flow-cytometric (FC) DNA-ploidy evaluation are either technically difficult or limited to three- to four-color immunophenotyping and hence, challenging to evaluate DNA-ploidy in minute tumor population with background rich of its normal counterpart cells and other hematopoietic cells. We standardized a novel sensitive and easy method of simultaneous evaluation of six- to seven-color immunophenotyping and DNA-ploidy using a dye-FxCycle Violet (FCV). Linearity, resolution, and coefficient of variation (CV) for FCV were studied using chicken erythrocyte nuclei. Ploidy results of FCV were compared with Propidium iodide (PI) in 20 samples and intra-assay variation for FCV was studied. Using this six-color immunophenotyping & FCV-protocol DNA-ploidy was determined in bone-marrow samples from 124 B-ALL & 50 MM patients. Dilution experiment was also conducted to determine the sensitivity in detection of aneuploidy in minute tumor population. FCV revealed high linearity and resolution in 450/50 channel. On comparison with PI, CV of Go/G1-peak with FCV (mean-CV 4.1%) was slightly higher than PI (mean-CV 2.9%) but had complete agreement in ploidy results. Dilution experiment showed that aneuploidy could be accurately detected up to the limit of 0.01% tumor cells. Intra-assay variation was very low with CV of 0.005%. In B-ALL, hypodiploidy was noted in 4%, hyperdiploidy in 24%, near-hyperdiploidy in 13% and remaining 59% were diploid. In MM, hypodiploidy was in 2%, hyperdiploidy in 58%, near-hyperdiploidy in 8% and remaining 30% were diploid. FCV-based DNA-ploidy method is a sensitive and easy method for simultaneous evaluation of six-color immunophenotyping and DNA analysis. It is useful in DNA-ploidy evaluation of minute tumor population in cases like minimal residual disease and MM precursor conditions.

Certain blood values of the Siberian roach Rutilus rutilus in affected area of warm water from Gusinoozerskaya State District Power Plant (Eastern Siberia)

The erythron parameters of Siberian roach inhabiting Gusinoe Lake were determined for the first time in an area of warm water discharged from the Gusinoozerskaya State District Power Plant (SDPP) (Eastern Siberia). It was noted that the defects of erythropoiesis identified (degenerative changes in the cytoskeleton, cytoplasm structure, and erythrocytes nuclei and a tendency to the development of hypochromic anemia) were obviously due to the combined impact of chemical and heat pollution of the water area of Gusinoe Lake by water discharged from the SDPP.

A novel field technique to assess ploidy in introduced Grass Carp (Ctenopharyngodon idella, Cyprinidae)

Invasions by Asian carps have become a high profile topic due to the threat they pose to native ecosystems and associated economies. One of four primary invasive Asian carp species, Grass Carp, Ctenopharyngodon idella (Cyprinidae), is commonly produced as triploid, sterile, individuals and stocked as a biological control for the suppression of unwanted aquatic vegetation. Illegal sale and transport of diploid fish can result in unwanted fertile populations. Current methods of determining ploidy of an individual require the use of laboratory equipment (Coulter Counter) and are not possible to perform under field conditions. Here we introduce a rapid, inexpensive technique to distinguish diploid fertile versus triploid sterile Grass Carp under field conditions using a compound microscope. We compared blood smears of known diploid and triploid Grass Carp individuals, finding that the frequency of abnormally shaped erythrocyte nuclei (dumbbell or teardrop shaped) is significantly higher in the latter. This difference is accompanied by larger cell and increased nuclear volumes, and it is significantly correlated with Coulter Counter values (the standard measure of ploidy used by the United States Fish and Wildlife Service). Additionally, we field tested our method on a managed, presumably triploid, standing stock of Grass Carp and found that all individuals tested exhibited proportions of abnormal nuclei typical of triploids. Finally, a blinded study was used to confirm diagnostic reliability of our visual assessment of ploidy. Examination of blood smears for abnormally shaped nuclei may become a powerful tool in the management of invasive Grass Carp.

Characterization of triploid hybrid groupers from interspecies hybridization (Epinephelus coioides♀ ×Epinephelus lanceolatus♂)

Interspecies hybridization is widely used in aquaculture as a beneficial strategy. Diploid and triploid hybrids have been detected from the interspecies hybridization of Epinephelus coioides ♀ × Epinephelus lanceolatus ♂. This is the first report of triploidization through hybridization in grouper. Confirmation has been obtained through flow cytometry, karyotyping and erythrocyte nuclei measurement. The chromosome numbers of E. coioides, E. lanceolatus, diploid hybrid grouper are 48 and triploid hybrid grouper are 72. Measurements of erythrocyte nuclei indicate that triploid fish have a larger nuclear surface than the diploid groupers, and the average ratio of triploid to diploid surface area is 1.59. During the first 1.5 years, triploid hybrid groupers grow faster than diploid hybrid groupers or either parent species. The average growth rate of triploid hybrids is 1.61 times greater than that of diploid hybrids at 6 months of age and 1.43 times greater at 18 months of age. The triploid hybrid groupers are inferior in gonadal development, with no primary-growth-stage oocytes appearing in the gonads at 18 months of age. Morphological studies indicate that triploid hybrid groupers have distinctive differences in snout length, eye diameter, body trunk shape, and tail shape development compared with diploid hybrid groupers. Triploid hybrid groupers have an advantage in growth ability, and artificial breeding of triploid groupers might be of great potential use in the grouper aquaculture industry.

Morphological and molecular characterization of Karyolysus--a neglected but common parasite infecting some European lizards.

BackgroundBlood parasites of the genus Karyolysus Labbé, 1894 (Apicomplexa: Adeleida: Karyolysidae) represent the protozoan haemogregarines found in various genera of lizards, including Lacerta, Podarcis, Darevskia (Lacertidae) and Mabouia (Scincidae). The vectors of parasites are gamasid mites from the genus Ophionyssus.MethodsA total of 557 individuals of lacertid lizards were captured in four different localities in Europe (Hungary, Poland, Romania and Slovakia) and blood was collected. Samples were examined using both microscopic and molecular methods, and phylogenetic relationships of all isolates of Karyolysus sp. were assessed for the first time. Karyolysus sp. 18S rRNA isolates were evaluated using Bayesian and Maximum Likelihood analyses.ResultsA total of 520 blood smears were examined microscopically and unicellular protozoan parasites were found in 116 samples (22.3% prevalence). The presence of two Karyolysus species, K. latus and K. lacazei was identified. In total, of 210 samples tested by polymerase chain reaction (PCR), the presence of parasites was observed in 64 individuals (prevalence 30.5%). Results of phylogenetic analyses revealed the existence of four haplotypes, all part of the same lineage, with other parasites identified as belonging to the genus Hepatozoon.ConclusionsClassification of these parasites using current taxonomy is complex - they were identified in both mites and ticks that typically are considered to host Karyolysus and Hepatozoon respectively. Furthermore although distortions to the intermediate host erythrocyte nuclei were observed, the defining characteristic of Karyolysus, the haplotypes were nearly identical to those reported from lizards in the Iberian Peninsula, where such distortions were not reported and which were thus identified as Hepatozoon. Based on the phylogenetic analyses, neither vertebrate host, nor geographical patterns of the studied blood parasites could be established.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-014-0555-x) contains supplementary material, which is available to authorized users.