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

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

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

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

Incidental capture of marine turtles by the Italian trawl fishery in the north Adriatic Sea

In the north Adriatic Sea on-board observations on midwater and bottom trawlers were carried out during years 1999 and 2000. Results indicate that the north Adriatic Sea, and especially the north-east part, is a very important foraging and overwintering habitat for loggerhead turtles (Caretta caretta). Since the distribution of fishing effort in the area is not known, the total turtle catch by the Italian bottom trawl fleet was conservatively estimated from the lower catch rate observed in the south-west sub-area: 4273 turtle captures/year (95% C.I.=2186-8546). The actual total catch in the whole north Adriatic is likely to be much higher, due both to an unknown Italian trawling effort in the south-west part with multi-gear vessels and to the Italian and Croatian trawling efforts in the north-east part, where catch rate was 15 times greater than in the south-west part. In the south-west sub-area 9.4% of captured turtles were dead and potential mortality (assuming that all comatose turtles would die too) was 43.8%. Hence, trawling in the north Adriatic is likely to represent a serious threat to the populations, and possible conservation measures are discussed. © 2004 Elsevier Ltd. All rights reserved

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

Preliminary results of aerial surveys of bluefin tuna in the western Mediterranean sea

One of the aims of the EU project STROMBOLI (2000-2002) was to conduct an aerial survey for bluefin tuna in the western Mediterranean Sea to test the feasibility of computing an index of abundance from direct observation. This approach has at least two advantages: (i) to provide fishery-independent information and observation, and (ii) to compensate for the lack of Mediterranean purse seine CPUE indices. The first surveys were done in June-July 2000 over the Balearic and Sicilian areas, where and when adult bluefin tuna used to concentrate for spawning, but the results were disappointing (spawners can hardly be detected from a plane). In contrast, the results obtained from the surveys for juveniles of BFT in the Gulf of Lions and in the Ligurian and Tyrrhenian seas are positive and encouraging. The number of BFT schools being detected was, on average, rather high and the variance between transects appeared satisfactory. Furthermore, the main characteristics, e.g., location and size of schools, fish behaviour, perpendicular distance of the detection, were consistent between the 2000 and 2001 surveys. This study will be pursued and extended in 2002.L’un des objectifs du projet européen STROMBOLI (2000-2002) était de mener des survols aériens sur le thon rouge de Méditerranée occidentale pour voir s’il était possible de calculer un indice d’abondance par méthode directe. Cette approche présente au moins deux avantages: (i) fournir des observations et des informations indépendantes de la pêche et (ii) compenser l’absence d’indices de CPUE des thoniers senneurs méditerranéens. Les premières campagnes de survols ont eu lieu en juin, juillet 2000 au dessus des îles Baléares et de la Sicile, date et lieu de la période de reproduction du thon rouge, mais les résultats furent décevants (les thons adultes étant peu détectables d’avion). Cependant, les résultats obtenus lors des survols axés sur les juvéniles du Golfe du Lions et de mer Ligure et Tyrrhénienne se sont avérés positifs et encourageants. Le nombre de bancs de thons détectés était, en moyenne, assez élevé et la variance entre transects satisfaisante. De plus, les principales caractéristiques, e.g., emplacement et taille des bancs, comportement du poisson, distances perpendiculaires des détections, étaient homogènes entre les campagnes 2000 et 2001. Cette étude sera poursuivie et étendue en 2002.Uno de los objetivos del proyecto STROMBOLI (2000-2002) de la UE era llevar a cabo expediciones aéreas que sobrevolasen el atún rojo occidental para ver si era posible calcular un índice de abundancia por método directo. Este enfoque presenta por lo menos dos ventajas. (i) proporcionar observaciones e informaciones independientes de la pesca y (ii) compensar la ausencia de índices de CPUE de los cerqueros atuneros mediterráneos. Las primeras campañas de expediciones aéreas tuvieron lugar en junio y julio de 2000 sobrevolando las islas Baleares y Sicilia, fecha y lugar de reproducción del atún rojo, pero los resultados fueron decepcionantes (los atunes adultos no se detectaban bien desde el avión). Sin embargo, los resultados obtenidos en los vuelos centrados en los juveniles del Golfo des Lions y del mar de Liguria y del mar Tirreno fueron positivos y alentadores. El número de bancos de atunes detectados fue, como media, bastante elevado y la varianza entre cortes transversales satisfactoria. Además, las principales características, por ejemplo, ubicación y tamaño de los bancos, conducta de los peces, distancias perpendiculares de las detecciones, eran homogéneas en las distintas campañas 2000 y 2001. Este estudio continuará y se ampliará en 2002

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

Lectin histochemistry on the dorsal epidermis of the Breton dog

Expression of sugar residues and the nature of oligosaccharide linkage during keratinocyte maturation in the epidermis of the Breton dog were studied with the use of lectin histochemistry. Thirteen lectins were used. Labelling was not observed with GSA I-B4, GSA II, UEA-I, and LTA. The cytoplasm of keratinocytes reacted with PNA, HPA, Con A, and WGA from the basal layer to the granular layer. PNA and Con A showed highest reactivity in the granular cell layer. The cell surface showed increased reactivity with PNA, HPA, and WGA with maturation of keratinocytes. KOH-neuraminidase treatment (KOH-Neu) increased PNA and RCA120 staining during keratinocyte differentiation thus indicating an increase in oligosaccharides terminating with sialic acid-Galβ(1,3)GalNAc and sialic acid-Galβ(1,4)GlcNAc, respectively. Labelling of the glycocalyx of basal and spinous keratinocytes with SNA and MAA revealed terminal Neu5acα(2,6)Gal/GalNAc and Neu5acα(2,3)Galβ(1,4)GlcNAc. KOH-Neu-DBA showed oligosaccharides terminating with sialic acid-GalNAcα(1,3)GalNAc in the spinous and granular layers. A selective glycocalyx labelling of granular keratinocytes was observed with DBA and SBA. Reactions with MAA, PNA, DBA, RCA120, SBA, HPA, and WGA disappeared after the b-elimination reaction. Our findings indicate that Breton dog epidermis contains more O-linked than N-linked oligosaccharides and confirm that different subpopulations of keratinocytes can be distinguished by lectin histochemistry