The control of reproduction in finfish species through GnRH treatments

Fish in captivity can show some dysfunctions, at different levels, in the physiological processes of reproduction, due to the lack of synthesis or release of gonadotropins (GtHs) by hypophysis. As a consequence, a worsening of quality and quantity of spawned gametes, or a lack of egg and sperm spawning, can be observed. The farmers can act on fish reproductive cycle manipulating the environmental parameters of rearing, the diet, the genetics or using GnRH treatments. Nowadays, they are used mainly GnRH, synthesized in laboratory as analogues. These releasing factors, naturally produced by hypothalamus, let to overcome the technological and biological limits of the \u201ctraditional\u201d hormonal treatments with hCG, being more effective, cheaper and easily available on market. This article makes a historical survey of the conditioning treatments for fish reproduction and also considers the future perspectives of these treatments, examining the topics that research will have to focus, in order to make these treatments common worldwide, in any hatchery and for each farmed species of finfish

Comparative study on milt quality features of different finfish species

The aim of this research was to study the main sperm characteristics of three different finfish species. Twenty-one gilt- head sea bream (Sparus aurata), 20 brown trout (Salmo trutta, morpha fario) and 15 rainbow trout (Oncorhynchus mykiss) male broodstocks, farmed under optimal conditions for each species and fed standard diets for broodstocks, were manually stripped. Brown trout yielded small amounts of sperm (4.5 vs18.13 ml) that were very concentrated (≅8.5 x 109 vs 1.24 x 109 Szoa/ml) with respect to the other species. The duration of spermatozoan motility for gilthead sea bream sperm was significantly longer (almost 50 min), in comparison to the one-minute motility of Salmonids. Single fatty acids of brown trout sperm were higher than in the other two species for almost all detected fatty acids. In partic- ular, eicosapentaenoic acid (EPA) was at least three times more concentrated in brown trout than in rainbow trout or gilt- head sea bream sperm (1238.3 µg/g vs305.6 and 333.3 µg/g, respectively; P < 0.01). Saturated, polyunsaturated and total unsaturated fatty acid classes were significantly higher in brown trout sperm than in the other two species - almost double with respect to gilthead sea bream sperm and more than double in comparison to RT sperm (P < 0.01)

Effects of vitamin E and phosphatidylcholine on qualitative and quantitative parameters of rainbow trout (Oncorhynchus mykiss) milt

The aim of this work was to investigate the effects of vitamin E and phosphatidylcholine on rainbow trout (Oncorhynchus mykiss) milt. One hundred and twelve rainbow trout (RB) broodstock (2n, 1030± 20g body weight, male:female ratio = 50:50) were fed four isoproteic and isolipidic diets for 110 days. Diets were differing for the type of vitamin premix and phosphatidylcholine supplied: Control (vitamin premix without Vit. E, no phosphatidylcholine); Vit.E (a premix with Vit. E, no phosphatidylcholine); PhC, (vitamin premix without Vit. E, phosphatidylcholine 2.5%); Vit.E +PhC, (vitamin premix with Vit. E and phosphatidylcholine 2.5%). Sperm total volume, in sexually mature males (3+; 966±114g body weight), ranged between 18.57ml (Control) and 34.31ml (Vit. E). Sperm density varied between 1.76x109 Szoa/ml (Control) and 1.16x109 Szoa/ml (Vit. E+PhC), while relative density (related to male body weight) tended to increase with Vit. E (>50x109 Szoa/ml) and to reduce with Vit. E + PhC (85% in all treatments, while motility duration was around 2.37min for Vit. E and Control reached only 0.97min. After overnight storage (+4°C, for 18 hours) motility decreased, 75-80% in gamete motility and 3.39- 56.7% in time motility. PhC dietary supplements significantly increased arachidonic acid contents of sperm with respect to Control (>120 vs 73μg/ g), while Vit. E caused a huge increase in C20:3 n-3 (10.25 vs 2.27ppm). DHA/EPA ratio was significantly lower in Control (>2; p<0.05), while n-3/n-6 ratio was significantly the highest for Vit. E (9.46 vs <7.3)

Review of the Scientific Literature on Biology, Ecology, and Aspects Related to the Fishing Sector of the Striped Venus (Chamelea gallina) in Northern Adriatic Sea

Striped venus (Chamelea gallina) is one of the most important fish resources on the west coast of the Adriatic Sea. Recently, there has been a widespread die-off of C. gallina populations in Friuli-Venezia Giulia (northern Adriatic Sea, Italy), probably due to unfavorable climatic events. Overall, wild populations have become increasingly rare due to many factors affecting the ecological balance of the species. In this study, the available literature was reviewed to determine the current state of knowledge on the biology, ecology, fisheries, and status of C. gallina populations with reference to populations in Friuli-Venezia Giulia. However, few data are available in terms of peer-reviewed articles; much of it can be found in the gray literature (e.g., project reports, ministerial reports, institutional websites, etc.). However, a critical review of the sources reveals that the species is as endangered as the habitats it inhabits. As a result, conservation and restoration efforts have been undertaken to date as part of some larger project to protect the species. Therefore, considering the ecological and economic importance of this species, the results of the new studies will be useful for the scientific community and will be a key element in the conservation of this species

Andreev reflection in graphene nanoribbons

We study Andreev reflection in graphene nanoribbon/superconductor hybrid junctions. By using a tight-binding approach and the scattering formalism we show that finite-size effects lead to notable differences with respect to the bulk graphene case. At subgap voltages, conservation of pseudoparity, a quantum number characterizing the ribbon states, yields either a suppression of Andreev reflection when the ribbon has an even number of sites in the transverse direction or perfect Andreev reflection when the ribbon has an odd number of sites. In the former case the suppression of Andreev reflection induces an insulating behavior even when the junction is biased; electron conduction can however be restored by applying a gate voltage.Comment: 6 pages, 6 figure

Simulating the exchange of Majorana zero modes with a photonic system

The realization of Majorana zero modes is in the centre of intense theoretical and experimental investigations. Unfortunately, their exchange that can reveal their exotic statistics needs manipulations that are still beyond our experimental capabilities. Here we take an alternative approach. Through the Jordan-Wigner transformation, the Kitaev's chain supporting two Majorana zero modes is mapped to the spin-1/2 chain. We experimentally simulated the spin system and its evolution with a photonic quantum simulator. This allows us to probe the geometric phase, which corresponds to the exchange of two Majorana zero modes positioned at the ends of a three-site chain. Finally, we demonstrate the immunity of quantum information encoded in the Majorana zero modes against local errors through the simulator. Our photonic simulator opens the way for the efficient realization and manipulation of Majorana zero modes in complex architectures

Aneuploidy and chromosomal instability in cancer: a jackpot to chaos

Genomic instability (GIN) is a hallmark of cancer cells that facilitates the acquisition of mutations conferring aggressive or drug-resistant phenotypes during cancer evolution. Chromosomal instability (CIN) is a form of GIN that involves frequent cytogenetic changes leading to changes in chromosome copy number (aneuploidy). While both CIN and aneuploidy are common characteristics of cancer cells, their roles in tumor initiation and progression are unclear. On the one hand, CIN and aneuploidy are known to provide genetic variation to allow cells to adapt in changing environments such as nutrient fluctuations and hypoxia. Patients with constitutive aneuploidies are more susceptible to certain types of cancers, suggesting that changes in chromosome copy number could positively contribute to cancer evolution. On the other hand, chromosomal imbalances have been observed to have detrimental effects on cellular fitness and might trigger cell cycle arrest or apoptosis. Furthermore, mouse models for CIN have led to conflicting results. Taken together these findings suggest that the relationship between CIN, aneuploidy and cancer is more complex than what was previously anticipated. Here we review what is known about this complex ménage à trois, discuss recent evidence suggesting that aneuploidy, CIN and GIN together promote a vicious cycle of genome chaos. Lastly, we propose a working hypothesis to reconcile the conflicting observations regarding the role of aneuploidy and CIN in tumorigenesis

Impiego di miscele di mono-di-trigliceridi nella dieta per riproduttori di trota fario (Salmo trutta trutta)

3nonenoneBALLESTRAZZI R; RAINIS S; DELZOTTO RBallestrazzi, Rodolfo; Rainis, Simona; DEL ZOTTO, Robert