Molecular DNA variation among Triturus vittatus vittatus (Urodela) from different breeding sites at the southern limit of its distribution

Molecular DNA variation among Triturus vittatus vittatus (striped newt) from different breeding sites at the southern limit of the species distribution (where environmental conditions are most extreme) was studied by the random amplification of polymorphic DNA (RAPD) method that has been found to be appropriate for other Triturus species. Altitudes of the localities ranged between 15-740 m a.s.l. Of the 20 primers employed, OPA-16 was the only one suitable for T. vittatus, revealing a different band pattern for different populations. Genetic similarity was calculated by band sharing, which demonstrated a high similarity among the Israeli populations

Transcription of Insulin-like Growth Factor Receptor in Russian Sturgeon (Acipenser gueldenstaedtii) Ovary during Oogenesis

Abstract In the present study, we examined the insulin-like growth factor receptor 1(IGF-1R) transcription using real-time PCR at different stages of oocytes of Russian sturgeon (Acipenser gueldenstaedtii) at age 8-9 years and weight 25 kg that were grown under aquaculture conditions. Compare to the pre-vitellogenesis stage, the transcription of IGF-1R increased at the vitellogenesis stages (yellow, gray and black). The mRNA of IGF-1R of oocytes in the black stage is significantly higher than in the gray or yellow stages. However, there are no significant differences between the gray or yellow stages of the mRNA level. Based on previous studies and the result of the mRNA of IGF-1R of oocytes during oogenesis, we proposed a model for the effect of GH, IGF-1 and IGF-1R on the oogenesis of Russian sturgeon, which is a very important process for creating caviar

Gonadotropins in the Russian Sturgeon: Their Role in Steroid Secretion and the Effect of Hormonal Treatment on Their Secretion.

In the reproduction process of male and female fish, pituitary derived gonadotropins (GTHs) play a key role. To be able to specifically investigate certain functions of Luteinizing (LH) and Follicle stimulating hormone (FSH) in Russian sturgeon (Acipenser gueldenstaedtii; st), we produced recombinant variants of the hormones using the yeast Pichia pastoris as a protein production system. We accomplished to create in vitro biologically active heterodimeric glycoproteins consisting of two associated α- and β-subunits in sufficient quantities. Three dimensional modelling of both GTHs was conducted in order to study the differences between the two GTHs. Antibodies were produced against the unique β-subunit of each of the GTHs, in order to be used for immunohistochemical analysis and to develop an ELISA for blood and pituitary hormone quantification. This detection technique revealed the specific localization of the LH and FSH cells in the sturgeon pituitary and pointed out that both cell types are present in substantially higher numbers in mature males and females, compared to immature fish. With the newly attained option to prevent cross-contamination when investigating on the effects of GTH administration, we compared the steroidogeneic response (estradiol and 11-Keto testosterone (11-KT) in female and males, respectively) of recombinant stLH, stFSH, and carp pituitary extract in male and female sturgeon gonads at different developmental stages. Finally, we injected commercially available gonadotropin releasing hormones analog (GnRH) to mature females, and found a moderate effect on the development of ovarian follicles. Application of only testosterone (T) resulted in a significant increase in circulating levels of 11-KT whereas the combination of GnRH + T did not affect steroid levels at all. The response pattern for estradiol demonstrated a similar situation. FSH levels showed significant increases when GnRH + T was administered, while no changes were present in LH levels

Genetic Variation In Strains Of Discus (Symphyodon Aequifaciata) Using RAPD PCR

The DNA of five strains of discus (Symphyodon aequifaciata) were compared by random ampli- fied polymorphic DNA (RAPD PCR) using seven primers. Only two primers (ZG4 and ZG8) were suitable. Using primer ZG8, the red turquoise strain had five bands common to at least one fish of another strain and two bands common to all the fish in the red turquoise strain. Panda turquoise had one band in common with at least one fish of another strain and seven bands common to all panda turquoise. For royal red, these figures were five and one and for common brown they were three and one. Within the strains, the level of band-sharing was 0.83 in the red turquoise strain, 0.13 in the panda turquoise, 0.83 in the royal red and 0.75 in the common brown. Specific bands were found only with primer ZG8 in the common brown and panda turquoise strains. Using primer ZG4, very low variation was found between the royal red, cobalt blue and red turquoise strains. With both primers, the highest genetic variation was between the common brown strain and the others (0.33-0.83)

Digestible energy in dietary sorghum, wheat bran, and rye in the common carp (Cyprinus carpio L.)

The digestibility of protein, fats, carbohydrates, and energy in three feed ingredients (sorghum, wheat bran, and rye) in common carp, Cyprinus carpio, was studied using the chromic oxide method. Three experimental diets were tested. Each contained 52.5% of a basal diet and 47.5% of the test ingredient. The carbohydrate levels in the test ingredients ranged 65-83% and the pro- tein levels ranged 11-18%. Therefore, carbohydrates were the main energy source. Results showed that the digestibility of protein in rye (91.89%) was significantly higher (p<0.05) than in sorghum (71.86%) and wheat bran (80.64%), producing 12.4, 6.7, and 9.3 kJ/g digestible ener- gy, respectively. The lipid levels in the test ingredients were very low, 1-4%. Lipid digestibility was 79.84%, 76.71%, and 82.01% in rye meal, sorghum meal, and wheat bran, respectively

Brain Control Reproduction by the Endocrine System of Female Blue Gourami (Trichogaster trichopterus)

Blue gourami belongs to the Labyrinithici fish and the Anabantiform order. It is characterized by a specific organ located above its gills for the respiration of atmospheric oxygen. This specific adaptation to low oxygen levels affects reproduction that is controlled by the brain, which integrates different effects on reproduction mainly through two axes&mdash;the gonadotropic brain pituitary gonad axis (BPG) and the hypothalamic-pituitary-somatotropic axis (HPS axis), including the interactions between them. This brain control reproduction of the Anabantoidei suborder summarizes information that has been published on the hormones involved in controlling the reproduction system of a model female blue gourami fish (Trichogaster trichopterus), including unpublished data. In the whole-brain transcriptome of blue gourami, 17 transcription genes change during vitellogenesis in the brain. The hormones involved in reproduction in blue gourami described in the present paper include: Kisspeptin 2 (Kiss 2) and its receptors 1 and 2 (KissR 1 and 2); gonadotropin-releasing hormone 1, 2 and 3 (GnRH1, 2 and 3); GnRH receptor; pituitary adenylate cyclase-activating polypeptide (PACAP) and its related peptide (PRP); somatolactin (SL); follicle-stimulating hormone (FSH); luteinizing hormone (LH); growth hormone (GH); prolactin (PRL), 17&beta;-estradiol (E2); testosterone (T); vitellogenesis (VTL); and 17&alpha;,20&beta;- dihydroxy-4-pregnen-3-one (17,20P). A proposed quality model is presented regarding the brain control oogenesis in blue gourami that has a Labyrinth organ about which relatively little information has been published. This paper summarizes the complex various factors involved in the interactions between external and internal elements affecting the brain of fish reproduction in the Anabantiform order. It is suggested to study in the future the involvement of receptors of hormones, pheromones, and genome changes in various organs belonging to the reproduction system during the reproduction cycles about which little is known

Economic Evaluation Of Multiple Research Innovations On An Eel Farm

An approach for evaluating multiple innovations of an aquaculture farm is proposed, based on a model of induced innovations, supplemented with a bio-economic table for the calculation of pro- duction function. Data gathered from a model eel farm were used as an example. The proposed approach enables evaluating each innovation to determine which is the most profitable

Breeding site selection according to suitability for amphibian larval growth under various ecological conditions in the semi-arid zone of northern Israel

A series of field monitoring was conducted over four years on aquatic habitats to test the hypothesis that breeding habitat selection by six different amphibian species, belonging to the Anuran and Urodela orders, was according to the ecological parameters of the water body, and not necessarily according to the type of breeding site. Ecological and biological conditions of 14 different breeding sites inhabited by amphibian larvae in northern Israel, including winter ponds, pits, springs and streams, were investigated in a region where all six species exist. The larval growth period was discovered to vary in different habitats. Most breeding sites studied had Salamandra infraimmaculata larvae, although at different periods of the year. The larvae of Hyla savignyi, Bufo viridis, Rana bedriagae, Pelobates syriacus and Triturus vittatus inhabited mostly the winter ponds and pits. In most cases, the S. infraimmaculata and T. vittatus larvae were not observed during the same time period at the same breeding sites. In other winter ponds, H. savignyi, P. syriacus and T. vittatus were seen at the same time during the spring, and along with R. bedriagae in the summer. Among the various water quality parameters evaluated at the breeding site, namely, temperature, pH, soluble oxygen, electrical conductivity, ammonium (NH 4 ) and invertebrate biomass, the most influential one was the temperature. S. infraimmaculata and B. viridis were detected in ponds with temperatures ranging about 1.5-24 °C, whereas all other larvae were observed at temperatures above this range, up to 34 °C. Based on the results of the investigation, the major factors affecting the habitat selected for breeding are the ecological conditions that allow for survival, growth and metamorphosis completion of the amphibian larvae.Goldber Tali, Nevo Eviatar, Degani Gad. Breeding site selection according to suitability for amphibian larval growth under various ecological conditions in the semi-arid zone of northern Israel. In: Ecologia mediterranea, tome 35,2009. pp. 65-74

Ovarian steroid levels in Salamandra salamandra infraimmaculata during the reproductive cycle. Gen Comp Endocrinol

Gonadal steroid levels were determined in the ovary of Salamandra salamandra infraimmaculata during the reproductive cycle in populations from a xeric region in northern Israel. Varying proportions of previtellogenic and vitellogenic oocytes were present throughout the year, and mature oocytes were present in winter and spring. The numbers of mature oocytes were greater between December and April, after parturition. The levels of 17b-estradiol and testosterone rose during oocyte vitellogenesis and maturation. Levels of progesterone and 17a-hydroxy progesterone appeared to be related to the level of vitellogenesis. Gravid females contained greater quantities of all four steroids than did nongravid females. r 1997 Academic Pres