Transcript level of telomerase reverse-transcriptase (TERT) gene in the rainbow trout (Oncorhynchus mykiss) eggs with different developmental competence for gynogenesis.

Expression of the telomerase reverse-transcriptase (TERT) gene and activity of telomerase have been reported in the somatic tissues and gonads in fish irrespective of their age and size. Nevertheless, little is known about TERT expression in the fish eggs. In the current study, the presence of the TERT transcripts was confirmed in the rainbow trout ovulated eggs before and after activation with nonirradiated and UV-irradiated (gynogenesis) sperm.

Application of high hydrostatic pressure (HHP) shock to induce triploid development in the European grayling (Thymallus thymallus L.).

Use of parental individuals from allochthonous lineages to produce stocking specimens resulted in genetic contamination of many local European grayling (Thymallus thymallus) populations. Stocking programs including triploid individuals that are not able to reproduce with stocks located in natural habitats due to being reproductively sterile could contribute to populations of the European grayling and prevent regional lineages from the genetic pollution. The main goal of the present research, therefore, was to provide conditions for triploidization of the European grayling and examine gonads of triploid individuals.

Preliminary Identification of Candidate Genes Related to Survival of Gynogenetic Rainbow Trout () Based on Comparative Transcriptome Analysis.

In the present research, the eggs from four rainbow trout females were used to provide four groups of gynogenetic doubled haploids (DHs). The quality of the eggs from different clutches was comparable, however, interclutch differences were observed in the gynogenetic variants of the experiment and the survival of DH specimens from different groups varied from 3% to 57% during embryogenesis. Transcriptome analysis of the eggs from different females exhibited inter-individual differences in the maternal genes' expression.

Telomere Dynamics in the Diploid and Triploid Rainbow Trout () Assessed by Q-FISH Analysis.

Changes of telomere length with age were assessed in diploid and triploid rainbow trout ) females in the cross-sectional study using Q-FISH technique. Triploid trout as sterile do not invest an energy in gametogenesis and continue to grow, whereas fertile diploid individuals suffer from declines in growth and survival during sexual maturation. However, triploid and diploid specimens exhibited similar patterns of telomere dynamics.

A Comparison of Pneumatic and Hand Stripping of Whitefish () Eggs for Artificial Reproduction.

We describe the technique of pneumatic stripping of whitefish () eggs with the use of oxygen, nitrogen, and air. Eggs obtained via the traditional method (by pressing the abdominal surfaces) served as a control group. It was established that the gas flow rate during pneumatic stripping should not exceed 0.

Induced androgenetic development in rainbow trout and transcriptome analysis of irradiated eggs.

Ionizing radiation is administered to damage nuclear genome in fish eggs during induced androgenesis. In this study, we examined whether 350 Gy of X-ray applied to damage chromosomes in the rainbow trout eggs affects maternal RNA. Shortly after irradiation, we did not find any symptoms of RNA degradation in the treated eggs.

Alterations in the rainbow trout (Oncorhynchus mykiss) eggs exposed to ionizing radiation during induced androgenesis.

Ionizing radiation (IR) is applied to inactivate nuclear genome in the salmonid eggs to induce androgenetic development. However, it has been considered that doses of IR used to damage maternal chromosomes may also affect morphology of the eggs and decrease their developmental potential. Thus, the main goal of the present research was to assess alterations in the rainbow trout (Oncorhynchus mykiss) eggs caused by the high dose of IR administered during androgenesis.

Corrigendum to "Transcriptome Analysis of Rainbow Trout () Eggs Subjected to the High Hydrostatic Pressure Treatment".

[This corrects the article DOI: 10.1155/2018/5197126.].

In vivo miRNA delivery in whitefish: Synthetic MiR92b-3p uptake and the efficacy of gene expression silencing.

The delivery of short snippets of RNA, such as synthetic miRNA agents, is an essential step for achieving RNA-mediated knockdown, which has not been studied in sufficient detail in fish. Our results indicate that a MiR92b-3p mimic may be effectively delivered via intraperitoneal injection to the spleen and the liver of whitefish, and that it likely achieves functionality without causing any apparent toxic effects in the challenged animals. We report the novel finding that the MiR92b-3p mimic reduced the in vivo liver mRNA expression levels of its putative pro-apoptotic targets (p53, cdkn1a, and pcna), and important metabolic genes, e.

Effectiveness of the Air Stripping in Two Salmonid Fish, Rainbow Trout (Oncorhynchus Mykiss) and Brown Trout (Salmo Trutta Morpha fario).

Egg collection is one of the most crucial procedures during fish reproduction in salmonid hatcheries. Classic methods involve the use of hand massage on fish abdomens to expel the eggs. An alternative method uses the pressure of gas injected into the body cavity, which causes the subsequent release of the eggs.

Transcriptome Analysis of Rainbow Trout () Eggs Subjected to the High Hydrostatic Pressure Treatment.

High hydrostatic pressure (HHP) causes depolymerization of the spindle microtubules. HHP applied to fish eggs prevents extrusion of the second polar body and inhibits the first cell cleavage, and it is used to produce triploids and diploid gynogenetic and androgenetic individuals. HHP has been also found to affect biomolecules including nucleic acids, and it may be presumed that HHP administered to the rainbow trout () eggs disturbs cytoplasmic maternal RNA indispensable for the early embryogenesis.

Developmental competence of eggs produced by rainbow trout Doubled Haploids (DHs) and generation of the clonal lines.

Poor quality eggs produced by the fully homozygous doubled haploids (DHs) may impair generation of clonal lines in fish species. In the present research, gynogenetic development of rainbow trout (Oncorhynchus mykiss) was induced in eggs originated from the DH females. Eggs were activated with the UV-irradiated grayling (Thymallus thymallus) spermatozoa and subjected to the high hydrostatic pressure (HHP) shock to provide diploid clonal individuals.

Genome incompatibility between rainbow trout (Oncorhynchus mykiss) and sea trout (Salmo trutta) and induction of the interspecies gynogenesis.

Rainbow trout (Oncorhynchus mykiss Walbaum) and sea trout (Salmo trutta Linnaeus, 1758) show large karyotypic differences and their hybrid offspring is not viable due to unstable karyotype and chromosome fragmentation. However, gametes from these two species were used to induce gynogenetic development. Rainbow trout eggs activated by UV-irradiated sea trout sperm were subjected to high hydrostatic pressure (HHP) shock to prevent release of the 2nd polar body (early shock) or to inhibit the first cleavage (late shock) in order to produce diploid meiotic gynogenotes and gynogenetic doubled haploids (DHs), respectively.

Effect of 11β-hydroxyandrostenedione on European whitefish Coregonus lavaretus (Linnaeus, 1758).

The goal of the present research was to evaluate the efficiency of 11β-hydroxyandrostenedione (OHA) applied in the diet to achieve sex reversal in the European whitefish (Coregonus lavaretus). At 32day post-hatching, fish were reared in four groups: fish fed with 10ppm of OHA (10 OHA), fish fed with 20ppm of OHA (20 OHA), fish fed without OHA (C) and fish fed without OHA and reared in the water from 20 OHA group (R). The experimental groups were conducted in separate recirculation systems and the first phase of the experiment lasted 63days.

High Rate of Deformed Larvae among Gynogenetic Brown Trout ( m. ) Doubled Haploids.

Mitotic gynogenesis results in the production of fully homozygous individuals in a single generation. Since inbred fish were found to exhibit an increased frequency of body deformations that may affect their survival, the main focus of this research was to evaluate the ratio of individuals with spinal deformities among gynogenetic doubled haploids (DHs) brown trout as compared to nonmanipulated heterozygous individuals. Gynogenetic development was induced by the activation of brown trout eggs by UV-irradiated homologous and heterologous (rainbow trout) spermatozoa.

Intraperitoneal exposure of whitefish to microcystin-LR induces rapid liver injury followed by regeneration and resilience to subsequent exposures.

To date, there has been no systematic approach comprehensively describing the sequence of pathological changes in fish during prolonged exposure to microcystin-LR (MC-LR). Towards this aim, juvenile whitefish individuals received an intraperitoneal injection with pure MC-LR, and the injection was repeated every week to maintain continuous exposure for 28days. During the exposure period, growth and condition of the fish were assessed based on biometric measurements.

Potassium ions in extender differentially influence the post-thaw sperm motility of salmonid fish.

Potassium ions are known to have an inhibitory effect on the sperm motility of salmonids. For this reason, the addition of K(+) to the extender is frequently applied. However, the effect of the addition of K(+) to the extender has not yet been tested.

Effect of dilution in sperm maturation media and time of storage on sperm motility and fertilizing capacity of cryopreserved semen of sex-reversed female rainbow trout.

Masculinized females, also called neomales or sex-reversed females have a male phenotype but retain the female genotype (XX). Therefore, all spermatozoa produced in their functional testes carry an X chromosome, which is desired for the production of all-female rainbow trout populations. Semen of sex-reversed female rainbow trout is of low quality and in vitro maturation is required, which includes dilution of sperm suspensions with specially formulated maturation solutions.

Androgenetic development of X- and Y-chromosome bearing haploid rainbow trout embryos.

Haploid fish embryos are important in studies regarding role of the recessive traits during early ontogeny. In fish species with the male heterogamety, androgenetic haploid embryos might be also useful tool in studies concerning role of the sex chromosomes during an embryonic development. Morphologically differentiated X and Y chromosomes have been found in a limited number of fish species including rainbow trout (Oncorhynchus mykiss Walbaum 1792).

Maturation of spermatozoa from rainbow trout (Oncorhynchus mykiss) sex-reversed females using artificial seminal plasma or glucose-methanol extender.

Masculinized females (sex-reversed females) produce only homogametic spermatozoa (X) for fertilization which is desired for the production of all-female rainbow trout populations. The milt of sex-reversed females is of low quality and must be matured through extension in maturation solutions. The aim of this study was to compare the usefulness of glucose-methanol (GM) extender with artificial seminal plasma (ASP) extender for the maturation of milt of sex-reversed female rainbow trout.

Identification of multiple diagnostic SNP loci for differentiation of three salmonid species using SNP-arrays.

This paper reports the use of SNP-array technology in a cross-species study for non-ambiguous species identifications. Based on an existing SNP-array for Atlantic salmon (cross)hybridisations with samples of salmon, brown trout and rainbow trout were analyzed to identify species-specific diagnostic markers. In total 566 SNP loci were identified to be highly polymorphic across the three salmonid species providing the molecular basement for various monitoring applications in aquaculture and food industries.

Induction of androgenetic development of the brook charr (Salvelinus fontinalis)× Arctic charr (Salvelinus alpinus) hybrids in eggs derived from the parental species.

Failure of interspecific androgenesis between brook charr (Salvelinus fontinalis, Mitchill 1814) and Arctic charr (Salvelinus alpinus, L.) has been attributed to the conflict between the egg cytoplasm of one species and the sperm nucleus of the other species. To overcome this incompatibility, sperm derived from the brook charr×Arctic charr hybrid male was used to induce androgenetic development in eggs originating from the parental species as well as their hybrids.

Genotyping of two populations of Southern Baltic Sea trout Salmo trutta m. trutta using an Atlantic salmon derived SNP-array.

The sea trout (Salmo trutta m. trutta) is an anadromous, teleost fish species characterized by homing behaviour. The sea trout has considerable ecological and economic significance.

Biochemical and physiological characteristics of semen of sex-reversed female rainbow trout (Oncorhynchus mykiss, Walbaum).

This works studies the biochemical (protein concentration, osmolality, antitrypsin activity, lactate dehydrogenase activity) and physiological characteristics (sperm motility characteristics) of semen of sex-reversed female rainbow trout (n=42) obtained with the application of 11β-hydroksyandrostendione for sex reversal. All data were arbitrarily divided into three classes depending on the percentage of sperm motility: I XX<25%; II XX 25-50% and III XX>50%. The average percentage of sperm motility was 18±7% n=12 (group I XX); 42±6% n=15 (group II XX) and 65±12% n=15 for group III XX, respectively) to link the values of semen parameters to the maturation stage of semen.