Marco Cardinali

Coral reef fish breeding: the secrets of each species

Abstract In recent years, the interest in the trade of tropical fish has increased significantly, with direct negative repercussions on coral reefs and marine ecosystems. The reproduction and rearing of some of the species most commonly used in the aquarium trade actually represent an economical and ecological tool for broadening development. The present study illustrates the first case ever of a small Indo-Pacific Pomacentridae, Chrysiptera parasema , successfully reared in captivity. Eggs were obtained from spawners reared in 80-l tanks under controlled conditions. Spawning began after 3 months: the couples were formed, and eggs were laid after a brief courtship. The male normally guarded the nest and chased away the female if she entered it. The eggs, about 300 in number, are demersal and elongate ovoidal in shape, measuring approximately 1.2–1.5 mm and coming with a large oil globule. Hatching took place at 28 °C during the first 2 h of darkness, over a total time period of 96 h. A proper diet of enriched PUFA as a first food, combined with a photoperiod of 24L/0D, proved essential for survival of the C. parasema larvae. These results are very promising in terms of both future captive production of ornamental fish and efforts to minimize environmental impact.

Molecular components related to egg viability in the gilthead sea bream, Sparus aurata.

In pelagic egg spawners, the production of large numbers of sinking eggs, unable to develop into embryos, represents one of the major limiting factors in controlled reproduction. The aim of this study is to elucidate the molecular differences between floating and nonfloating eggs at cytoplasmic and nuclear level. Comparison of analyses between floating and nonfloating sea bream Sparus aurata eggs evidenced differences in vitelline envelope protein components, such differences being probably related with the hydration process but not with fertilization as supported by the assessment of DNA that doubled after in vitro insemination. These data clearly indicated that the absence of embryo development in nonfloating eggs is not due to lack of fertilization. The cytoplasmic composition was also different, the number of protein components being higher in floating eggs, and these extra components may generate the appropriate osmotic pressure at the base of the hydration process. Some lysosomal enzymes, such as cathepsin D and L both involved in yolk proteolysis, in virgin nonfloating eggs were significantly higher with respect to floating ones; the levels of these two enzymes significantly increased in the latter after fertilization. On the contrary, in nonfloating eggs cathepsin L significantly decreased after fertilization. These changes may be related with a series of metabolic processes vital for the production of viable offspring. The capacity of egg transcription and the protein synthesis in these two types of eggs, indicated by the RNA/DNA and RNA/protein ratios, evidenced that the status of cell transcription rate and protein synthesis capacity is significantly higher in floating eggs. This, in turn, suggested that the lack of embryo development may be due to low levels of proteins involved in cell cycle regulation. Mol. Reprod. Dev. 58:330–335, 2001.

Peptide pheromones in newts

This article reviews the current state of understanding of reproductive pheromones in amphibians, focusing mainly on the purification and characterization of peptide pheromones in newts of the genus Cynops, molecular cloning of cDNAs encoding the pheromone molecules, and hormonal control of secretion of these pheromones. Pheromones that attract sexually developed female Cynops pyrrhogaster and C. ensicauda newts were isolated from the male abdominal glands. The C. pyrrhogaster and C. ensicauda pheromones are peptides, designated sodefrin and silefrin, with the amino acid sequences SIPSKDALLK and SILSKDAQLK, respectively. Each pheromone attracts only conspecific females. Molecular cloning of cDNAs encoding sodefrin and silefrin revealed the presence of precursor proteins that are considered to generate these pheromone peptides. Pheromone precursor mRNA levels and radioimmunoassayable pheromone concentrations in the abdominal glands were elevated by prolactin and androgen. Sexual dimorphism and hormone dependency of the responsiveness of vomeronasal epithelium to sodefrin were noted. Significance of pheromones in the form of peptide for those performing reproductive behavior in an aquatic environment was also discussed.

Hormonal control of the IGF system in the sea bream ovary

Abstract: Numerous studies have described the presence of an intragonadal IGF system involved in regulation of gametogenesis in teleost fish. In the present study, the in vivo effects of estradiol‐17β (E2) and growth hormone (GH) exposure on IGF‐I, IGF‐II, IGF1R, and IGFBP2 gene expression in sea bream ovary were monitored by RT‐PCR during prereproductive and reproductive periods. The evidence demonstrates that both hormones investigated here affect the ovarian IGF system, showing that it is not only under GH control, but also can be regulated by sexual hormones; this hormonal modulation is related to reproductive phase.

Diplodus sargus interrenal–pituitary response: chemical communication in stressed fish

In the present study the response of white sea-bream (Diplodus sargus), used as experimental model, to different stocking densities was tested to assess whether the induced stress conditions were able to activate a chemical communication. Once a good recovery was evident, six days after capture and transportation, experiments started to evaluate eventual changes in cortisol plasma levels as well as in both plasma and pituitary alpha-melanocyte stimulating hormone (alpha-MSH) levels. These studies demonstrated that a low stocking density (2.5kg/1000L) is not deleterious for this species while a higher one (10kg/1000L) induces the activation of the hypothalamus-pituitary-interrenal axis (HPI). Thus, in these fish were evident both a significant increase of cortisol plasma levels and a significant decrease of alpha-MSH pituitary levels, while no significant changes were detected in alpha-MSH plasma concentrations. The most relevant result reported in this study, for the first time in marine species, is the presence of a chemical communication among stressed fish. It also should be noted that the data obtained from cortisol and alpha-MSH detections strongly indicate a gender specificity of this chemical signal.

Temperature-dependent prolactin secretion and reproductive biology of the newt Triturus carnifex Laur

The effects of temperature on pituitary prolactin (PRL) gene expression and peripheral levels were studied in both male and female newts obtained from wild conditions during reproductive (Experiment I) and nonreproductive (Experiment II) periods; moreover, changes in parameters related to reproductive function are also described. Male and female newts were taken from a pond in February (Experiment I, reproductive period) and maintained for 1 month in tanks at 4 and 18 degrees C. In male newts kept at 4 degrees C, increase of PRL mRNA in the pituitary and plasma PRL was found compared with that measured in those kept at 18 degrees C. The increase in PRL secretion was parallel to that of plasma androgens and related secondary sexual characteristics (SSC) in males and of plasma estradiol-17beta and vitellogenin in females. On the contrary, in nonreproductive newts (Experiment II), taken from the field in May, no significant changes in plasma PRL, androgens, and SSC were found in those maintained at low temperature (4 degrees C), whereas low temperature significantly increased PRL mRNA expression in the male pituitary and PRL mRNA plus plasma PRL levels in females. These findings suggest that low temperature regulates PRL secretion in this urodele species, showing a sex- and season-related control mechanism; moreover, low temperature failed to influence the reproductive biology of newts taken from the field in May, after naturally occurring reproduction during winter months.

Gut microbiota profile in systemic sclerosis patients with and without clinical evidence of gastrointestinal involvement

Recent evidence suggests that there is a link between the gut microbial community and immune-mediated disorders. Systemic sclerosis (SSc) is an autoimmune disease characterized by immunonological abnormalities, vascular lesions, and extensive fibrosis. Since the gastrointestinal tract is one of the organs most involved, the goal of this study was to explore the composition of the intestinal microbiota in SSc patients with (SSc/GI+) and without gastrointestinal involvement (SSc/GI-) in comparison to healthy controls (HC). The fecal bacterial composition was investigated by Illumina sequencing of 16 S rRNA gene amplicons. The fecal microbiota of SSc/GI+ subjects was characterized by higher levels of Lactobacillus, Eubacterium and Acinetobacter compared with healthy controls, and lower proportions of Roseburia, Clostridium, and Ruminococcus. The gut microbiota of SSc/GI- subjects was more similar to the microbiota of HC than to that of SSc/GI+ subjects albeit Streptococcus salivarius was over-represented in SSc/GI- fecal samples compared with both SSc/GI+ subjects and controls. Our study reveals microbial signatures of dysbiosis in the gut microbiota of SSc patients that are associated with clinical evidence of gastrointestinal disease. Further studies are needed to elucidate the potential role of these perturbations in the onset and progression of systemic sclerosis, and gastrointestinal involvement in particular.

A painful diagnosis

Dr. Fraticelli: A 53-year-old man was admitted to our department for a 10-day history of widespread limb pain, worsening in the evening and sometimes so excruciating to make him feel faint. These symptoms were not triggered by particular events or behaviors, and not relieved by rest or particular positions. He did not report fever, weight loss, night sweats, joint pain or any other systemic symptom. The patient’s history was of notable complexity. He had been suffering from allergic asthma during his youth. Twenty years before the current evaluation, hypertrophic cardiomyopathy was reported on a routine echocardiography. In the recent years, he also developed a mild arterial hypertension. Two years before admission, the patient had an acute coronary syndrome secondary to a noteworthy three-vessel coronary disease. At that time he was treated only with medical therapy. Later on he had a syncope, consequent with third grade atrio-ventricular blockade, that required the implantation of a pacemaker with ICD. During the stay in the cardiac surgery ward, he developed progressive weakness of lower limbs, with reduction of the tendon reflexes and sensitivity. Basing on the results of electromyography and cerebrospinal fluid analysis, a diagnosis of Guillain–Barrè syndrome was made and a subsequent trial with intravenous immunoglobulin (Ig) infusion (0.4 g/kg/day for 5 days) was successful. One year before presentation, the patient was admitted to our ward for the acute onset of hemoptysis. The physical examination revealed the presence of mild respiratory crackles on auscultation of both lung bases and a mild sensitivity reduction in the lower limbs. The main laboratory findings were an increase in the serum creatinine levels (1.77 mg/dL) and mild hemoglobinuria and proteinuria (1 g/day) on urinalysis. A high-resolution computed tomography (HRCT) of the chest revealed the presence of a ground-glass pattern, suggestive of alveolitis, and the subsequent bronchoscopy with bronchoalveolar lavage showed the presence of hemosiderin-containing macrophages. Globally considered, the findings were suggestive of a systemic vasculitis with multisystem involvement. The presence of high titers of perinuclear anti-neutrophil cytoplasmic antibodies (p-ANCA) and the pauci-immune glomerulonephritis found on lightmicroscopy examination of the renal biopsy lead to the diagnosis of microscopic polyangiitis (MPA) (Fig. 1). The patient was treated with daily prednisone (starting from 50 mg/day) and one cycle of rituximab (375 mg/m g every week for 4 weeks [1]), followed by mycophenolate mofetil as steroid-sparing long-term treatment, achieving a consistent tapering of the prednisone dose. At the last follow-up, the disease appeared in remission. Ten months before our evaluation, the patient was admitted to the emergency department for a typical chest pain associated with cold sweating. After retrieval of abnormal ECG findings and elevation of cardiac enzymes, the patient underwent a coronary arteriography, which showed worsening of the known three-vessel stenosis. The & Paolo Fraticelli paolo.fraticelli@ospedaliriuniti.marche.it