Expression and secretion of albumin in male turkey (Meleagris gallopavo) reproductive tract in relation to yellow semen syndrome1.

Yellow semen syndrome (YSS) is the most widely recognized problem among male turkeys. Yellow semen is of low quality and, when used for insemination, results in reduction of fertility and hatchability. Elevated level of serum albumin-like protein accession no. XP_003205725 is a characteristic feature of yellow seminal plasma suggesting albumin role in YSS pathology. However, knowledge regarding the expression of albumin in the reproductive tract in relation to YSS is very limited. The aim of this study was to identify albumin secretion and localization sites in the turkey reproductive tract in relation to YSS. Reproductive tract tissues and liver originating from turkeys producing white semen (WS) and YSS were used for analysis of albumin mRNA expression and its localization using immunohistochemistry. Moreover, albumin abundance in tissues, blood and seminal plasma was analyzed using two dimensional electrophoresis and western blot analysis. Albumin mRNA expression was found in all parts of the reproductive tract. Apart from the liver, the highest expression of albumin was found in the ductus deferens in YSS turkeys. The testicular spermatids, Leydig, and myoid cells and the epithelium of the epididymis and ductus deferens were the main secretion sites of albumin in the reproductive tract in turkeys. Higher albumin abundance was found in the reproductive tract and seminal plasma of YSS toms compared to WS toms. Our results demonstrated that germ cells from spermatocytes to spermatids, Leydig cells, and myoid cells synthesized and secreted albumin in turkey testis, and epithelial cells are the main secretion sites in epididymis and ductus deferens. Ductus deferens secretion of albumin seems to be mostly responsible for YSS. Over-secretion by the ductus deferens may be the main origin of albumin abundance in YSS semen. Knowledge regarding disturbances of albumin secretion in relation to YSS may be useful for future work on studies related to better understanding the molecular basis of YSS.

Mass marking of Leuciscus idus larvae using Artemia salina as a vector of fluorescent dyes.

A method for the mass marking of ide Leuciscus idus larvae by feeding them Artemia salina nauplii that were immersed in different solutions of alizarin red S, tetracycline hydrochloride and calcein was tested. The best quality marks were obtained after feeding fish for 4 days with nauplii that had been immersed in 200 mg l(-1) alizarin red S.

Characterization of lake minnow Eupallasella percnurus semen in relation to sperm morphology, regulation of sperm motility and interpopulation diversity.

Sperm morphology and regulation of sperm motility of lake minnow Eupallasella percnurus, an endangered cyprinid, were investigated. Milt characteristics from two isolated populations of E. percnurus were compared to characterize the interpopulation diversity. Electron microscopic studies revealed that E. percnurus spermatozoa comprise simple, uniflagellate, anacrosomal aquasperm with species-specific features as an eccentrically located implantation of nuclear fossa and eccentric insertion of flagellum. Sperm motility was significantly inhibited by relatively low ion concentrations (150, 150 and 8 mM for NaCl, KCl and CaCl2 , respectively). Sperm maintained a high motility rate over a wide pH range (5.5-10.5), which may reflect adaptation to a highly variable environment. The two E. percnurus populations were markedly different in milt volume, sperm concentration, seminal plasma pH, sperm motility and beat cross frequency, which may result from genetic differences and environmental conditions.

Changes in sperm parameters of sex-reversed female rainbow trout during spawning season in relation to sperm parameters of normal males.

The production of all-female populations has important economic benefits in commercial rainbow trout aquaculture. The procedure commonly implemented to produce all-female stocks centers on the sex reversal of rainbow trout females via the administration of androgens in the early developmental stages, followed by the egg fertilization of normal females with semen from sex-reversed females (srf). However, there is no information regarding the quality of semen from srf rainbow trout throughout the spawning season. This information is critical because the quality of srf semen is highly variable. The aim of the study was to determine the changes in the semen parameters of srf rainbow trout throughout the duration of the spawning season. Sperm concentration, sperm motility parameters, and the biochemical parameters of seminal plasma (protein concentration, antitrypsin activity, osmolality, and lactate dehydrogenase activity) from srf were monitored during the spawning season and compared with normal male rainbow trout. The observed values of sperm, protein concentration, antitrypsin activity, osmolality, and lactate dehydrogenase activity of seminal plasma were all higher in comparison with normal males. Semen from srf was therefore characterized by a lower sperm motility during each period of the spawning season, in comparison with normal males, approximately 1.8, 1.5, and 1.7 times, respectively for the beginning, middle, and end of the spawning season. The percentage of sperm motility from srf and normal males were affected by the spawning season in the same way, as the highest values in the middle of the spawning season demonstrate (60% and 91% for srf and normal males, respectively). Spermatozoa of srf are characterized by a lower speed and a more curvilinear trajectory of movement as compared with that of normal males. The patterns of changes during the spawning season in sperm concentration, sperm motility parameters, as well as osmolality, and lactate dehydrogenase activity of the seminal plasma of srf were different in comparison with normal males. Our results could be important for fish breeders in regard to the spawning control of srf rainbow trout, as well as for the development of short- and long-term sperm storage procedures.

Karyotype and chromosomal characteristics of Ag-NOR sites and 5S rDNA in European smelt, Osmerus eperlanus.

Karyotype and cytogenetic characteristics of European smelt Osmerus eperlanus were investigated using different staining techniques (sequential Ag-, CMA3 and DAPI banding) and PRINS to detect 5S rDNA and telomeric sites. The diploid chromosome number was invariably 2n = 56 and karyotype composed of 5 pairs of metacentrics, 9 pairs of subtelocentrics and 14 pairs of subtelo- to acrocentrics. The DAPI-positive heterochromatic regions were found in centromeric positions on bi-armed chromosomes and few acrocentrics. Additionally, some interstitial DAPI-positive bands were identified on three pairs of submetacentric chromosomes. The nucleolar organizer regions (NORs) were detected in the short (p) arms of the largest metacentric pair of chromosomes No. 1. Sequential banding (Giemsa-, AgNO(3) and CMA(3) stainings) revealed NOR sites corresponding to achromatic regions but not associated with CMA(3)-positive blocks of heterochromatin located on either side of NORs. Individuals from the analyzed population had this conspicuous pair of chromosomes always in heterozygous combination. A complex inversion system was hypothesized to be involved in the origin of the observed variation but analysis with telomeric PRINS and PNA-FISH did not reveal any Interstitial Telomeric Sites (ITS). Hybridization signals were confined exclusively to terminal chromosomal regions. The 5S ribosomal sites as revealed by PRINS were found to be invariably located in the short (p) arms of four pairs of subtelocentric chromosomes. Cytotaxonomic comparisons of the present results with the voluminous available cytogenetic data-set from salmoniform and esociformes fishes appear to support the recent view, based on robust molecular-based phylogeny, that salmoniform and osmeriform fishes are not as closely related as previously assumed.

Indispensable amino acid concentrations decrease in tissues of stomachless fish, common carp in response to free amino acid- or peptide-based diets.

The premise that free amino acid or dipeptide based diets will resolve the nutritional inadequacy of formulated feeds for larval and juvenile fish and improve utilization of nitrogen in comparison to protein-based diets was tested in stomachless fish, common carp (Cyprinus carpio L.) larvae. We examined the postprandial whole body free amino acid (FAA) pool in fish that were offered a FAA mixture based diet for the duration of 2 or 4 weeks. We found that the total amount and all indispensable amino acids concentrations in the whole body decreased after a meal. We then fed juvenile carp with dietary amino acids provided in the FAA, dipeptide (PP), or protein (live feed organisms; brine shrimp Artemia salina nauplii, AS) forms. Histidine concentrations in the whole fish body increased in all dietary groups after feeding whereas all other indispensable amino acids decreased in FAA and PP groups in comparison to the AS group. Taurine appears to be the major osmotic pressure balancing free amino acid in larval freshwater fish which may indicate a conditional requirement. We present the first evidence in larval fish that in response to synthetic FAA and PP diets, the whole body indispensable free AA concentrations decreased after feeding. This study shows that amino acids given entirely as FAA or PP cannot sustain stomachless larval fish growth, and may result in depletion of body indispensable AA and most of dispensable AA. The understanding of these responses will determine necessary changes in diet formulations that prevent accelerated excretion of amino acids without protein synthesis.