Differential lectin binding patterns in the oviductal ampulla of the horse during oestrus

We investigated the oligosaccharide sequence of glycoconjugates, mainly sialoglycoconjugates, in the horse oviductal ampulla during oestrus by means of lectin and pre-lectin methods such as the KOH-neuraminidase procedure to remove sialic acid residues and incubation with N-glycosidase F to cleave N-linked glycans. Ciliated cells displayed N-linked oligosaccharides throughout the cytoplasm. The cilia glycocalyx expressed both N- and O-linked (mucin-type) oligosaccharides, both showing a high variety of terminal sequences. In the most non-ciliated cells, the whole cytoplasm contained N-linked oligosaccharides with terminal αGal as well as mucin-type glycans with terminal Forssman pentasaccharides. In a few scattered non-ciliated cells, the whole cytoplasm displayed sialylated N-linked oligosaccharides with terminal Neu5Ac-GalNAc and O-linked glycans terminating with neutral and/or αGalNAc, Neu5Acα2,6Gal/ GalNAc, Neu5AcGalβ1,3GalNAc. Supra-nuclear granules, probably Golgi zones, of non-ciliated cells showed mainly O-linked glycans rich in sialic acid residues. The luminal surface of non-ciliated cells showed N-linked oligosaccharides, containing terminal/internal αMan/αGlc, βGlcNAc and terminal αGal, as well as mucin-type oligosaccharides terminating with a large variety of either neutral saccharides or sialylated sequences. Apical protrusions containing O-linked oligosaccharides with terminal Forssman pentasaccharide, Neu5Ac-Galβ1,4GlcNAc, Neu5Ac-GalNAc were seen in nonciliated cells scattered along the epithelium. These findings show the presence of sialoglycoconjugates in the oviductal ampulla epithelium of the mare and the existence of different lectin binding profiles between ciliated and non-ciliated (secretory) cells, as well as the presence of non-ciliated cell sub-types which might determine functional differences along the ampullary epithelium of mare oviduct

The First Spontaneous Spawning of Red Drum Sciaenops Ocellatus L. in Europe: Broodstock Management and Early Larval Stages

The present paper reports a research on reproductive parameters and larval rearing of red drum (Sciaenops ocellatus) maintained in captivity for the first time in Europe. Red drum juveniles were obtained from United States in the late 90s. In early January 2013, 40 in total male and female red drums ranging from 34 to 47 cm in length were held in a 25 m3 rectangular tank with a closed recirculating system with a water flow of 6000 L/h, located in Lesina (FG) fish farm (Southern Italy). Water temperature and salinity ranged between 21.0 and 28.8°C and from 25 to 27 g/L respectively. The fish were fed commercial feed pellet (46% protein) at 1.1% of body weight daily. Sexual maturation occurred during the natural breeding season of red drum. Approximately 43 spawns were recorded by the end of July and continuing to mid-September, with mean number of 66.5 millions of eggs collected overall on spawn period. Batch fecundity (3.325*106 ova per female) and relative fecundity (361.41 ova/g body weight) were calculated. Fertilisation rate was 30 to 80%. Larvae were hatched at a mean total length of 2.40±0.33 mm and showed a gradual increase in size of approximately 0.378 mm/day for the first 40 day after hatching (DAH). Cannibalism was observed as larger larvae preyed on smaller ones; to limit the phenomenon red drum population was selected for size at 35 DAH. Reliable information on fecundity and larval stage is essential for encouraging Sciaenops ocellatus farming also in Mediterranean countries

A Multi-Biomarker Approach in European Sea Bass Exposed to Dynamic Temperature Changes under Dietary Supplementation with Origanum vulgare Essential Oil

A feeding trial for 150 days was carried out to evaluate the cross-effects between oregano essential oil (EO) dietary supplementation and dynamic temperature change in sea bass. Under exposure to rising temperature (13–25 °C), fish were fed with a control diet (CD) and two experimental diets supplemented with 100 (D100) and 200 ppm (D200) of EO. Feed inclusion of EO promoted the activity of antioxidant enzymes in sea bass exposed to increasing temperature. Consistently with the temperature rise, TBARS concentrations increased in CD and D200 groups, whereas were almost stable in D100. Trend of blood glucose in fish fed on CD was likely affected by glycogenolysis and gluconeogenesis. Similarly, the depletion of triglycerides and cholesterol in fish fed on CD likely supported the energy cost of gluconeogenesis. On the other hand, the reduction of glucose, triglycerides, and cholesterol in D100 and D200 was mainly attributable to the hypoglycemic and hypolipidemic effects of EO. The higher levels of serum protein observed in D100 and D200 groups were also associated to a reduced thermal stress compared to CD. EO dietary supplementation may be a promising strategy to alleviate the negative effects of temperature shift on sea bass physiological and oxidative state

Distribution of sialoglycoconjugates in the oviductal isthmus of the horse during anoestrus, oestrus and pregnancy: a lectin histochemistry study

The distribution of sialic acid residues as well as other glycosidic sugars has been investigated in the horse oviductal isthmus during anoestrus, oestrus and pregnancy by means of lectin and pre-lectin methods. Ciliated cells and non-ciliated (secretory) cells exhibited different lectin binding profiles that were found to change during the investigated stages. Ciliated cells did not show any reactivity in the basal cytoplasm, while the supra-nuclear cytoplasm displayed a few of oligosaccharides with terminal and internal amannose (Man) and/or aglucose (Glc) during oestrus and pregnancy and a moderate presence of oligosaccharides terminating in afucose (Fuc) during oestrus; cilia exhibited a more complex glycoconjugate pattern for the presence of oligosaccharides terminating in N-acetylgalactosamine (GalNAc), GalNAca1,3 GalNAca1,3galactose(Gal)b1,4Galb1,4N-acetylglucosamine( GlcNAc), Fuc, sialic acid (Neu5Ac)-aGalNAc belonging or not to the GalNAca1,3GalNAca1,3 Galb1,4 Galb1, 4GlcNAc sequence, and.aGalNAc and Neu5Aca 2,6Gal/GalNAc increased during oestrus. Cilia displayed terminal Galb1,3 GalNAc in pregnancy, terminal aGal in anoestrus and pregnancy and terminal or internal D-GlcNAc during anoestrus and pregnancy, respectively. The whole cytoplasm of non-ciliated cells showed oligosaccharides terminating with aGalNAc, Neu5Aca2,6Gal/GalNAc, Neu5Ac GalNAca 1,3GalNAca1,3Galb1,4Galb1,4GlcNAc during the investigated stages, as well as GlcNAc in anoestrus and pregnancy. The supra-nuclear zone of non-ciliated cells exhibited oligosaccharides with terminal Galb1,4GlcNAc and internal Man during oestrus and pregnancy as well as terminal aGal and Fuc in oestrus and Neu5Ac-Galb1,3GalNAc in pregnancy. The luminal surface of non-ciliated cells showed glycans terminating with aGalNAc and/or Neu5Ac GalNAca1,3 GalNAca1,3Galb1,4Galb1,4GlcNAc in all specimens, oligosaccharides with terminal Galb1,4GlcNAc and internal Man during oestrus and pregnancy, Neu5Ac a2,6Gal/GalNAc in anoestrus and oestrus, and glycans terminating with Galb1,3GalNAc, Neu5A aca2,3 Galb1, 4GlcNac, Neu5ac- Galb1,3GalNAc, Neu5Ac-Galb1,4 GlcNAc in pregnancy. These findings show the presence of sialoglycoconjugates in the oviductal isthmus of the mare as well as the existence of great modifications in the glycoconjugates linked to different physiological conditions

Brain morphology and immunohistochemical localization of the gonadotropin-releasing hormone in the bluefin tuna, <i>Thunnus thynnus</i>

The present study was focused on the morphology of the diencephalic nuclei (likely involved in reproductive functions) as well as on the distribution of GnRH (gonadotropin-releasing hormone) in the rhinencephalon, telencephalon and the diencephalon of the brain of bluefin tuna (Thunnus thynnus) by means of immunohistochemistry. Bluefin tuna has an encephalization quotient (QE) similar to that of other large pelagic fish. Its brain exhibits well-developed optic tecta and corpus cerebelli. The diencephalic neuron cell bodies involved in reproductive functions are grouped in two main nuclei: the nucleus preopticus-periventricularis and the nucleus lateralis tuberis. The nucleus preopticus-periventricularis consists of the nucleus periventricularis and the nucleus preopticus consisting of a few sparse multipolar neurons in the rostral part and numerous cells closely packed and arranged in several layers in its aboral part. The nucleus lateralis tuberis is located in the ventral-lateral area of the diencephalon and is made up of a number of large multipolar neurones. Four different polyclonal primary antibodies against salmon (s)GnRH, chicken (c)GnRH-II (cGnRH-II 675, cGnRH-II 6) and sea bream (sb)GnRH were employed in the immunohistochemical experiments. No immunoreactive structures were found with anti sbGnRH serum. sGnRH and cGnRH-II antisera revealed immunoreactivity in the perikarya of the olfactory bulbs, preopticus-periventricular nucleus, oculomotor nucleus and midbrain tegmentum. The nucleus lateralis tuberis showed immunostaining only with anti-sGnRH serum. Nerve fibres immunoreactive to cGnRH and sGnRH sera were found in the olfactory bulbs, olfactory nerve and neurohypophysis. The significance of the distribution of the GnRHimmunoreactive neuronal structures is discussed

Histological and immunohistochemical investigation on ovarian development and plasma estradiol levels in the swordfish (<i>Xiphias gladius</i> L.)

The paper reports a histological and immunohistochemical description of oocyte growth and ultrastructural aspects of zona radiata (ZR) formation as well as the relationship between plasma estradiol-17&#x03B2;, (E2 ) levels and ovarian development in swordfish (Xiphias gladius L.) from the Mediterranean Sea. Ovaries were inactive during March to mid April; maturation occurred during late April to June and spawning in June and July. Zona radiata formation starts, as Pas positive material, in oocytes at the lipid stage. In this stage a deposit of electrondense material between oolemma and follicular cells appears. In the cortical alveoli stage and through the early vitellogenic stage, the deposition of a moderately electrondense material occurred on the inner side of the ZR. Finally, in late vitellogenic oocytes a third layer, made of microfibrillar material, appeared. The immunohistochemical analyses revealed that the initial internalisation of hepatic zona radiata proteins (Zrp) in the swordfish oocyte starts before the uptake of vitellogenin (Vtg) and that it is associated with the low previtellogenic E2 plasma levels, while a significant E2 increase in plasma is associated with the beginning of Vtg uptake. This would appear to confirm the hypothesis that the differential and sequential induction of zonagenesis and vitellogenesis may reflect a general feature of teleost oogenesi

Glycohistochemical study of the toadfish <i>Halobatrachus didactylus</i> (Scheider, 1801) stomach

Toadfish Halobatrachus didactylus gastric mucosa was studied using conventional and lectin histochemistry. Conventional histochemistry revealed neutral glycoconjugates predominating over acidic ones in the apical zone of both surface epithelial cells and pit cells. The neck cells contained a few neutral glycoconjugates, whereas gastric glands were negative to PAS and AB staining. Lectin histochemistry showed different oligosaccharide expression along the columnar cells. The sub-nuclear cytoplasm was stained with RCA120, SBA, HPA, GSA I-B4, GSA II, UEA I, LTA, Con A, KOH-sialidase-WGA. The Golgi zone reacted with RCA120, DBA, SBA, HPA, KOH-sialidase-WGA, GSA I-B4, GSA II, UEA I, LTA, MAL II, SNA, and showed an increase in DBA staining after KOH-sialidase treatment. The granules of the apical zone stained with PNA, UEA I, LTA and showed increased PNA reactivity after KOH-sialidase treatment. The luminal cell coat reacted with PNA, HPA, Con A, KOH-sialidase-WGA, UEA I, LTA, MAL II, SNA and KOH-sialidase-PNA. Pit cells showed a minor expression of lectin-binding sites with respect to columnar cells. Neck cells linked UEA I and LTA and gastric glands reacted with PNA, DBA, SBA, HPA, Con A, GSA I-B4, KOH-sialidase-WGA and KOH-sialidase-DBA. The results suggest that the stomach of the toadfish H. didactylus is characterised by a species-specific glycoconjugate pattern

Expresión glucohistoquímica en el estómago del pez sapo, Halobatrachus didactylus (Schneider,1801)

11 pages, 6 figures, 2 tables.[EN] Toadfish Halobatrachus didactylus gastric mucosa was studied using conventional and lectin histochemistry. Conventional histochemistry revealed neutral glycoconjugates predominating over acidic ones in the apical zone of both surface epithelial cells and pit cells. The neck cells contained a few neutral glycoconjugates, whereas gastric glands were negative to PAS and AB staining. Lectin histochemistry showed different oligosaccharide expression along the columnar cells. The sub-nuclear cytoplasm was stained with RCA120, SBA, HPA, GSA I-B4, GSA II, UEA I, LTA, Con A, KOH-sialidase-WGA. The Golgi zone reacted with RCA120, DBA, SBA, HPA, KOH-sialidase-WGA, GSA I-B4, GSA II, UEA I, LTA, MAL II, SNA, and showed an increase in DBA staining after KOH-sialidase treatment. The granules of the apical zone stained with PNA, UEA I, LTA and showed increased PNA reactivity after KOH-sialidase treatment. The luminal cell coat reacted with PNA, HPA, Con A, KOH-sialidase-WGA, UEA I, LTA, MAL II, SNA and KOH-sialidase-PNA. Pit cells showed a minor expression of lectin-binding sites with respect to columnar cells. Neck cells linked UEA I and LTA and gastric glands reacted with PNA, DBA, SBA, HPA, Con A, GSA I-B4, KOH-sialidase-WGA and KOH-sialidase-DBA. The results suggest that the stomach of the toadfish H. didactylus is characterised by a species-specific glycoconjugate pattern.[ES] Se ha estudiado la expresión de residuos glucídicos de glucoconjugados en la mucosa gástrica del pez sapo, Halobatrachus didactylus usando histoquímica convencional y de lectinas. La histoquímica clásica reveló la presencia de glicoconjugados neutros predominando sobre los ácidos en la zona apical de la superficie de las células epiteliales y de la criptas gástricas. Las células del cuello contienen algunas glicoproteínas neutras, mientras las glándulas gástricas han sido negativas al PAS y al Azul Alcián (AB). La histoquímica de lectinas mostró diferente expresión de oligosacáridos a lo largo de las células columnares. El citoplasma sub-nuclear reaccionó con las lectinas RCA, SBA, HPA, GSA, I-B4, GSA II, UEA I, LTA, Con A, KOH-sialidasa-WGA. La expresión de RCA120, DBA, SBA, HPA, KOH-sialidasa-WGA, GSA I-B4, GSA II, UEA I, LTA, MAL II y SNA se localizó en la zona del Golgi, donde se observó un incremento de la reactividad de la lectina DBA después del tratamiento con KOH. Los gránulos de la zona apical reaccionaron con PNA, UEA I, LTA, mostrando un incremento de la reactividad hacia la lectina PNA después del tratamiento con KOH. El borde de las células del lumen reaccionó con PNA, HPA, ConA, KOH-sialidasa-WGA, UEA I, LTA, MAL II, SNA, KOH-sialidasa-PNA. Los sitios de unión de la expresión de las lectinas-glucoconjugados fue menor en las células del cuello de las criptas gastricas que en las células columnares epiteliales. Las células del cuello reaccionaron con la UEA I y LTA, y las glándulas gástricas con PNA, DBA, SBA, HPA, Con A, GSA I-B4, KOH-sialidasa-WGA y KOH-sialidasa-DBA. Los resultados sugieren que el estómago del pez sapo, Halobatrachus didactylus, se caracteriza por un patrón especie-específico de expresión de glicoconjugados.Peer reviewe

Increased by-catch rates in the Gulf of Taranto, Italy, in 20 years: A clue about sea turtle population trends?

Information on sea turtle population trends is fundamental to assess the population status and the effects of conservation measures, and is considered a priority for sea turtle conservation. To provide insights on trends at sea, we compared by-catch data from long-liners fishing in the Gulf of Taranto in 2 periods: 1978-1979 and 1998-2003. A total of 653 loggerhead sea turtles (Caretta caretta) were captured in 2679 fishing sets targeting swordfish and albacore tuna; catch rates were significantly higher in the second period, while average turtle size was smaller. Although possible effects of sampling techniques cannot be excluded, a negative trend in the number of turtles in the study area and period was unlikely. © 2012 Chelonian Research Foundation

Influence of season on the glycoconjugates surface of stallion ejaculated spermatozoa

Seasonal changes have been observed in stallion sperm morphology. Since carbohydrates of sperm glycocalyx play a key role in the sperm-egg recognition and zona binding, the aim of this study was to evaluate the distribution of carbohydrates in stallion ejaculates collected in two different periods of the year using lectin histochemistry. Semen from two fertile trotters was collected in winter (January) and summer (July) (3 ejaculates for each time), diluted in Tyrode’s medium, fixed in 4% (w/v) neutral formalin, smeared on slides and incubated with appropriate dilutions of 12 lectins. The spermatozoa from winter ejaculates reacted with 1) MAL II, SNA, HPA, Con A, WGA and GSA II in the whole cell surface, 2) PNA, RCA120 and SBA in the acrosomal region, 3) GSA I-B4 in the entire head, 4) DBA and UEA I in the post-acrosomal region and tail. The spermatozoa contained in summer ejaculates did not show GSA I-B4 reactivity, whereas they displayed SBA affinity also in post-acrosomal region which was unreactive to UEA I. In addition, the tail of July collected spermatozoa did not contain binding sites for UEA I and GSA II. These results suggest that the expression of oligosaccharide sequences of stallion sperm glycocalyx is time-dependent and that the acrosomal region shows a more stable glycoconjugate pattern with respect to other regions. Lastly, carbohydrate pattern of the glycocalyx could be important in the assessment of semen quality in stallions