Immunolocalisation of nitric oxide synthase isoforms in the ductuli efferentes and epididym.

The present research used immunohistochemistry to analyse the detection and localisation of nitric oxide synthase (NOS) isoforms in the ductuli efferentes and epididymis of prepubertal and adult alpaca. In the ductuli efferentes and epididymis of prepubertal and adult animals, nNOS and eNOS were similarly expressed in epithelial lining cells, conversely differences were observed in the immunopresence of iNOS. Our data provide evidence that NOS isoforms may have roles in reproductive functions and in the developmental processes of the excurrent duct system in the alpaca.

Gene Expression and Localization of NGF and Its Cognate Receptors NTRK1 and NGFR in the Sex Organs of Male Rabbits.

Experiments were devised to characterize the expression of nerve growth factor, beta polypeptide (NGF), and its cognate receptors neurotrophic tyrosine kinase receptor type 1 (NTRK1) and nerve growth factor receptor (NGFR) in rabbit male sex organs, as well as the concentrations of NGF in both seminal and blood plasma of sexually mature male rabbits. Immunoreactivity and gene expression for NGF and cognate receptors were detected in testis, prostate gland and seminal vesicle. The highest levels of NGF and NTRK1 transcripts were found in the prostate, while intermediate expressions were found in the testis. NGFR transcripts were expressed at the same levels in both testis and prostate and were more abundant than in seminal vesicles. The widespread distribution of NGF in all prostate glandular cells, together with its relative high mRNA abundance, confirms that the prostate of rabbits is the main source of this neurotrophin. In conclusion, the present data suggest that the NGF system is involved in the testicular development and spermatogenesis of rabbits and that NGF may act as a potential ovulation-inducing factor being abundantly present in the seminal plasma.

Glycomolecule modifications in the seminiferous epithelial cells and in the acrosome of post-testicular spermatozoa in the alpaca.

A lectin histochemical investigation of the seminiferous epithelium and acrosomes of spermatozoa present in the efferent ductules and epididymal regions was carried out in the alpaca. The histochemical characterization was performed using a battery of different lectins: Con-A, UEA-I, LTA, WGA, GSA-IB4, SBA, PNA, ECA, DBA, MAL-II and SNA. Sialidase digestion and deglycosilation pre-treatments were also employed. The cytoplasm of the Sertoli cells contained N-linked oligosaccharides with α-D-Man/α-D-Glc and GlcNAc and O-linked glycans with α-L-Fuc, ß-GalNAc, ß-D-Gal-(1-4)-D-GlcNAc, α-Gal and Neu5Acα2,6α-GalNAc moieties whereas ß-D-Gal-(1-3)-D-GalNAc residues were included in both O- and N-glycoproteins. Spermatogonia expressed α-D-Man/α-D-Glc residues included in N-glycoproteins and α-Fuc in O-glycoproteins. Spermatocytes contained the N-glycoproteins residues α-D-Man/α-D-Glc and GlcNAc and the O-glycoproteins residues α-L-Fuc, ß-D-Gal-(1-4)-D-GlcNAc, α-Gal, ß-GalNAc, Neu5Acα2,6α-GalNAc and Neu5Acα2,6ß-D-Gal-(1-3)-D-GalNAc. The results of the present study show differences in the presence and distribution of lectin reactive sites throughout the acrosomal development in the alpaca. In particular, Fuc moieties were found only during the Golgi-phase of spermatids, α-Gal were found in the acrosome of Golgi- and cap-phase spermatids, sialic-acid/α-GalNAc sequence was revealed during the cap-phase and elongated spermatids, and α-D-Man/α-D-Glc and GlcNAc were detected only in the acrosomes of elongated spermatids. Finally, ß-GalNAc, ß-D-Gal-(1-3)-D-GalNAc and ß-D-Gal-(1-4)-D-GlcNAc were added to acrosomal glycoproteins in the early stages of spermatogenesis and remained unchanged during the later phases. Differences in the carbohydrate expression were also demonstrated on the sperm acrosomes during passage through the post-testicular ducts.

Expression of prostate glycoconjugates in the stallion and castrated horse.

This work was undertaken to determine the glycoconjugates secreted by the epithelium of the prostate in the intact stallion and castrated horse using lectin histochemical procedures in conjunction with enzymatic digestion and deglycosylation treatments. Additionally, anti-5 and 13-16-cytokeratin antibodies were used to localize epithelial basal cells. In the stallion, lectin histochemistry showed the following sugar residues in the Golgi zone of the glandular cells: α-Glu/Man, α-Fuc and ß-Gal included in both O- and N-linked oligosaccharides as well as ß-GalNAc, GlcNAc and α-Gal, which belonged to O-glycoproteins. ß-Gal and ß-GalNAc moieties were also noted subterminal to sialyl residues. Sialic acid specific lectins identified Neu-5Ac(α2,3-6)-ß-Gal or Neu5Ac(α2,6)-ß-GalNAc sequences in both N- and O-bound glycoproteins. The prostatic glandular cells of the castrated horse expressed some of the same sugar moieties found in the stallions, such as α-Glu/Man, α-Gal and GlcNAc, but significant differences were also noted. In particular, ß-D-GalNAc was only detected subterminal to sialic acid, ß-D-Gal-(1-3)-D-GalNAc was found in N-linked glycans, whereas ß-D-Gal-(1-4)-D-GlcNAc and Neu5Acα2,6Gal/GalNAc were noted only in O-glycoproteins. These results indicate that the lectin binding patterns in glandular cells may be modified by sex hormones. No specific lectin labelling of basal cells was found in either the stallion or the castrated horse even though they were immunostained with specific anti-cytokeratin antibodies. These cells stained more strongly in the castrated horse than in the intact stallion suggesting that they are androgen responsive. The glycomolecules detected in the equine prostate secretions may contribute to the remodelling of the sperm surface, which occurs during sperm transit through the male genital tract and also after ejaculation in the seminal plasma. These changes may be important in the understanding of the stallion fertility.

Glycocomposition of the apocrine interdigital gland secretions in the fallow deer (Dama dama).

The secretions of the tubular interdigital glands were investigated by conventional (Periodic-Acid Schiff, Alcian-Blue at different pH, Low Iron Diamine and High Iron Diamine) and lectin (Con-A, UEA-I, LTA, WGA, GSA-II, GSA-IB4, SBA, PNA, ECA, DBA, MAL-II and SNA) histochemical methods in adult males and females of different age of fallow deer during the breeding season. Sialidase digestion and deacetylation pre-treatment were also employed in conjunction with lectin histochemistry. The glandular epithelium consisted of a single layer of low columnar cells with typical apical protrusions. No substantial differences of the above histochemical staining in relation to sex and age were observed. Conventional histochemical staining revealed that the interdigital glands secreted neutral glycoproteins whereas acidic glycocomponents did not seem to be present. Lectin histochemical technique allowed us to disclose a great heterogeneity of glycoproteins with N- and O-linked oligosaccharides containing alpha-d-Man/alpha-d-Glc, GlcNAc, alpha-Fuc, terminal beta-d-Gal-(1-3)-d-GalNAc, -d-Gal-(1-4)-d-GlcNAc, alpha-Gal and beta-GalNAc residues. beta-GalNAc and disaccharide beta-d-Gal-(1-3)-d-GalNAc were also found as subterminal to sialyl moieties. The lack of sexual and age-related differences in the glucidic content of the glandular secretions seems to indicate that the glycoderivatives may play only an accessory role in the production of odoriferous signals in fallow deer.

Differentiation of glycans in equine guttural pouches.

The aim of this study was to investigate the carbohydrate composition of mucosubstances in the equine guttural pouches using conventional histochemical tests in conjunction with glycolytic digestion to degrade different classes of glycosoaminoglycans. In the goblet cells, the mucopolysaccharides contained chondroitin sulfate B, heparin, heparan sulfate and sialic acid residues. The acinar cells also expressed these substances (except for heparin), whereas the ductal cells produced chondroitin sulfate B and sialic acid. Neutral sugars were also found in each cell type. The diversity of the glycocomponents found in the auditory tube suggests that they may have important functional roles. Indeed, the glycosoaminoglycans provide a hydrophilic environment that prevents dehydration and desiccation of the guttural membranes during air passage. Additionally, these glycomolecules may be involved in the pathogenesis of some bacterial disease in horses, such as equine strangles.

The ductus epididymis of the alpaca: immunohistochemical and lectin histochemical study.

Our objective was to characterize epithelial cells lining the epididymal duct (caput, corpus, cauda) of the alpaca using AE1/AE3 cytokeratin antibodies and a battery of different lectins: Con-A, UEA-I, LTA WGA, GSA-II, GSA-IB4, SBA, PNA, ECA, DBA, MAL-II and SNA. Sialidase digestion and deglycosylation pre-treatments were also employed. The principal cells (PCs) along the epididymis showed differences in immunostaining patterns toward keratin antibodies. Lectin histochemistry demonstrated variations in the content and distribution of glycosidic residues of glycoconjugates in different epididymal regions. In particular, staining of the Golgi zone in the epithelial PCs was interpreted as evidence for synthesis and secretion of O- and N-linked oligosaccharides. In the caput, the apical mitochondria-rich cells contained mainly beta-GalNAc, subterminal alpha-GalNAc, alpha-Gal and Neu5Ac alpha2,3Gal residues. Conversely, in the corpus they were particularly rich in alpha-GalNac and beta-Gal-(1-3)-d-GalNAc linked to sialic acid moieties. Basal cells mainly expressed beta-GalNAc and alpha-Gal in the caput, alpha-Gal in the corpus and alpha-Fuc and beta-GalNAc in the cauda. The differences in immunostaining patterns and in lectin histochemistry in the alpaca epididymis reported in this investigation seem to be related to regional differences in function.

Presence and function of kisspeptin/KISS1R system in swine ovarian follicles.

Kisspeptin and its receptor KISS1R are involved in the neuroendocrine regulation of mammalian reproduction and their role on follicular development and function can be hypothesized. The present work was designed to confirm the immunopresence of kisspeptin and its receptor in the ovary of swine and to study the effects of kisspeptin 10 and its antagonist, kisspeptin 234, on main functional parameters of granulosa cells (i.e. cell proliferation, steroid production, and redox status) as well as their modulatory action on angiogenesis. The immunopresence of kisspeptin and KISS1R were detected in granulosa cells. Kisspeptin 10 stimulated progesterone in vitro production, thus indirectly suggesting that it can have a role in the luteinization process of granulosa cells. Kisspeptin 10 displayed potentiating effects on non-enzymatic scavenging activity, thus supporting its involvement in the control of the antioxidant defense system of ovarian follicles. In addition, results from the angiogenesis bioassay suggest that kisspeptin may have a role in the physiological development of new ovarian vessels. Additional studies are needed to confirm the functional significance of the kisspeptin/KISS1R system within the swine ovary.

Expression of nerve growth factor and its receptors in the uterus of rabbits: functional involvement in prostaglandin synthesis.

The aim of the present study was to evaluate: (1) the presence of nerve growth factor (NGF), neurotrophic tyrosine kinase receptor 1 (NTRK1), and nerve growth factor receptor (NGFR) in the rabbit uterus; and (2) the in vitro effects of NGF on PGF2α and PGE2 synthesis and on the PGE2-9-ketoreductase (PGE2-9-K) activity by the rabbit uterus. Nerve growth factor, NTRK1, and NGFR were immunolocalized in the luminal and glandular epithelium and stroma cells of the endometrium. reverse transcriptase polymerase chain reaction indicated the presence of messenger RNA for NGF, NTRK1, and NGFR in the uterus. Nerve growth factor increased (P < 0.01) in vitro secretions of PGF2α and PGE2 but coincubation with either NTRK1 or oxide nitric synthase (NOS) inhibitors reduced (P < 0.01) PGF2α production and blocked (P < 0.01) PGE2 secretion. Prostaglandins releases were lower (P < 0.01) than control when uterine samples were treated with NGF plus cyclooxygenase inhibitor. However, addition of NGFR inhibitor reduced (P < 0.01) PGF2α secretion less efficiently than NTRK1 or NOS inhibitors but had no effect on PGE2 yield. Nerve growth factor increased (P < 0.01) the activity of PGE2-9-K, whereas coincubation with NTRK1 or NOS inhibitors abolished (P < 0.01) this increase in PGE2-9-K activity. However, cotreatment with either cyclooxygenase or NGFR inhibitors had no effect on PGE2-9-K activity. This is the first study to document the distribution of NGF/NTRK1 and NGFR systems and their effects on prostaglandin synthesis in the rabbit uterus. NGF/NTRK1 increases PGF2α and PGE2 productions by upregulating NOS and PGE2-9-K activities, whereas NGF/NGFR augments only PGF2α secretion, through an intracellular mechanism that is still unknown.

Apoptotic cell death in canine hair follicle.

Apoptotic cell death is an essential homeostatic mechanism involved in the control of cellular turnover in a variety of adult tissues. Cytoplasmic and nuclear condensation morphologically define this process whose biochemical hallmark is extensive DNA fragmentation into discrete oligonucleosomic units. Hair follicle growth and regression has been shown to be correlated with apoptosis in humans, mice, rats and guinea pigs. The present study was carried out to evaluate its implication in canine hair biology in order to define the spatio-temporal relationship between apoptosis and the hair cycle in dogs. As assessed by terminal deoxy-nucleotidyl transferase-mediated d-UTP nick-end-labelling (TUNEL) and by basic histological and ultrastructural assays, apoptotic cells appeared both in the growing and in the regressing follicle epithelium showing the well characterized morphological features described in the previous relevant literature.

Topographical localisation of glucidic residues and their variations in the canine zona pellucida during folliculogenesis.

In the present ultrastructural study, horseradish peroxidase-labelled lectins, in conjunction with antiperoxidase antibody and protein A-gold, were used to characterise and localise the oligosaccharide sequences of zona pellucida glycoproteins at different stages of follicular development in the canine ovary. Deacetylation and sialidase digestion were also performed before lectin cytochemistry. The zona pellucida of oocytes present in unilaminar primary follicles reacts with WGA- and RCA-I-lectins. The zona pellucida of oocytes present in bilaminar and trilaminar secondary follicles displays positivity to WGA, RCA-I, Con-A, UEA-I, and sialidase/SBA. This labelling pattern persists in the zona pellucida of oocytes present in antral tertiary follicles with the exception of WGA and RCA-I reactive sites which are differently distributed throughout the zona pellucida. The topographical distribution of these carbohydrates is not uniform throughout the zona pellucida, indicating the regionalization of oligosaccharide chains within three concentric bands of the zona matrix: an inner surface close to the oocyte plasma membrane, an intermediate portion and an outer layer in contact with the follicular cells. Our results demonstrated variations in the presence and distribution of the carbohydrate residues in the canine zona pellucida during different stages of follicular growth. We also observed the presence of vesicles in both the ooplasm and granulosa cells, showing a similar lectin binding pattern to that of the zona pellucida.

Detection of glycoconjugates in the ductus epididymis of the prepubertal and adult horse by lectin histochemistry.

This paper describes an approach for studying the structure of glycoconjugates found in the principal cells lining the epididymal duct in adult and prepubertal horses, using ten different lectin horseradish conjugates: Con-A, LCA, WGA, GSA-II, SBA, PNA, RCA-I, DBA, UEA-I, and LTA. Saponification and sialidase procedures, followed by lectin binding, were employed to visualize the distribution and to reveal the sequence of sialoglycoconjugates in ductus epididymis. In the adult horse the results demonstrated variations in the content and distribution of glycosidic residues of glycoconjugates in different epididymal regions (caput, corpus, cauda) and vas deferens, suggesting that each epididymal segment has a specific function. In particular, staining of the Golgi-zone in the principal cells lining corpus epididymis was interpreted as evidence for synthesis and secretion of glycoconjugates and sialoglycoconjugates. In the prepubertal horse, only the glycocalyx of the epithelial cells lining the epididymal duct showed reactivity toward the different lectins used, suggesting hormonal regulation of the epididymis activity. Additional, the heterogeneity of the lectin staining pattern of the adult horse epididymis reported in this investigation also suggests the existence of different functional segments along the epididymal duct.

Lectin-staining pattern in extratesticular rete testis and ductuli efferentes of prepubertal and adult horses.

This study was undertaken to determine the lectin affinity of the extratesticular rete testis and ductuli efferentes epithelial cells in adult and prepubertal horses, using ten different lectin horseradish peroxidase conjugates: Con-A, LCA, WGA, GSA-II, SBA, PNA, RCA-I, DBA, UEA-I, and LTA. In some cases, treatments with sialidase and KOH preceded the lectin staining. In sexually mature and immature horses the results showed the presence of different kinds of sialoglycoconjugates with the terminal sialic acid linked to D-GalNAc and beta-D-Gal residues in the rete testis. In the apical surface and cytoplasm of epithelial cells lining the ductuli efferentes of the adult horse, glycoconjugates with alpha-D-Man and/or alpha-D-Glc, GlcNAc, D-GalNac and beta-D-Gal residues were evidenced, whereas in the prepubertal horse only the apical surface of the ductuli efferentes epithelial cells resulted reactive toward some lectins. The differences observed in the presence of glycoconjugates between adult and prepubertal horse ductuli efferentes, suggest a hormonal control of the function of these tracts of the post-testicular ducts.

Glycohistochemical investigation of canine and feline zonae pellucidae of preantral and antral oocytes.

Glycoconjugate modifications were analysed in the zona pellucida during development of oocytes in dog and cat using conventional histochemical staining methods with or without previous carbohydrate digestion. A series of lectins combined with desulphation and sialic acid degradation were applied. No differences were observed between dog and cat follicles using conventional histochemical staining methods. In both species, the zona pellucida and follicular fluid/intercellular matrix strongly reacted with PAS and high iron diamine stain (HID) and reacted moderately with low iron diamine stain (LID). Treatment with testicular hyaluronidase, chondroitinase ABC, chondroitinase AC and chondroitinase B treatment diminished HID and LID positivity of follicular fluid and intercellular matrix. Lectins that gave the most intense staining of the zona pellucida of both species were SBA, PNA, RCA-I, GSA-IB4 and WGA, indicating the presence of beta-D-GalNAc, D-Gal and GlcNAc residues. Sulpho- and asulpho-carbohydrates were identified in terminal and/or subterminal positions linked to sialic acid residues. In conclusion, the results indicate that glycosaminoglycans are not present in the zona pellucida of both species. Differences were observed in carbohydrate residues and in their spatial distribution, depending on species and developmental stage of the follicles. The similarity in lectin affinity between ooplasm and zona pellucida of oocytes present in follicles at different stages of development confirm the involvement of oocytes in zona pellucida production.

Glycoconjugates in small antral ovarian follicles of the river buffalo (Bubalus bubalis L.).

Types and distribution patterns of glycoconjugates in antral ovarian follicles were investigated in the buffalo, using periodic-acid Schiff (PAS), high iron diamine (HID), low ion diamine (LID) and lectin histochemical staining methods. HID and LID staining procedures were preceded in some cases by digestion with testicular hyaluronidase, Streptomyces hyaluronidase, chondroitinase ABC and heparitinase (heparinase III). Lectin staining was performed with the use of 12 horseradish peroxidase (HRP) lectin conjugates. Some lectin staining procedures were preceded by neuraminidase digestion and saponification. Large amounts of isomeric chondroitin sulphates and a minor quantity of heparan sulphate and hyaluronic acid and/or chondroitin were found in follicular fluid. Lectin staining of buffalo follicular fluid revealed glycoconjugates with different glucidic determinants such as beta-N-acetylgalactosamine, beta-galactose-(1-3)-N-acetylgalactosamine, beta-galactose-(1-4)-N-acetylglucosamine, N-acetylglucosamine, alpha-fucose and alpha-glucose/alpha-mannose, and sialic acid residues. Glycosaminoglycans were absent in the zona pellucida of oocytes in small antral follicles. Acidic glycoconjugates in the zona pellucida were caused by sulphated groups and sialic acid residues. Our data show few internal glucidic residues, such as N-acetylglucosamine in the buffalo zona pellucida but many subterminal beta-N-acetylgalactosamine, alpha- and beta-galactose determinants masked by sialic acids. These findings demonstrate that buffalo follicular fluid has a very heterogeneous composition that is similar to that found in small and large bovine follicles. No differences in composition of the follicular fluid were observed in the follicles examined.

Lectin histochemical detection of sulfoglycans in the zona pellucida of mammalian antral oocytes.

Sulphated esters are important to increase effectiveness of specific biological activities of carbohydrates. Biochemical studies revealed the presence of distinct sulphated glycoproteins in mammal zona pellucida (ZP) that bind proacrosin and thus participate in the sperm-egg fusion processes. In the present study, 6 lectin-horseradish peroxidase conjugates (SBA, PNA, RCA-I, GSA-IB4, GSA-II and DBA) were used in combination with desulphation and sialidase digestion to identify sulphocarbohydrates in the terminal and/or subterminal position of oligosaccharide side chains of glycoproteins in the ZP of bovine, ovine, caprine and porcine antral oocytes. In particular, we identified the following terminal sulphoglycans located in the outer layer of the ZP only: SO4-GalNAc in bovine ZP; SO4-Galbeta1,3GalNAc in bovine and ovine ZP; SO4-Galbeta1,4GlcNAc in bovine, ovine and caprine ZP; SO4-alpha-Gal in bovine, caprine and porcine ZP. Subterminal sulphoglycans linked to sialic acid residues were evenly distributed throughout the entire thickness of the ZP: Neu5Ac-SO4-Galbeta1,3GalNAc in bovine and porcine ZP; Neu5Ac-SO4-Galbeta1,4GlcNAc in caprine ZP; Neu5Ac-SO4-alpha-Gal in porcine ZP; Neu5AcSO4-GlcNAc in bovine ZP. The results demonstrate that the chemical composition of the ZP differs among species determining the species-specificity of gamete interactions.

Immunogold study on lectin binding in the porcine zona pellucida and granulosa cells.

An ultrastructural localization of lectin receptors on the zona pellucida (ZP) of porcine antral oocytes and on the granulosa cells was performed using a panel of horseradish peroxidase-labelled lectins in conjunction with antiperoxidase antibody and protein A-gold. In some cases, lectin incubation was preceded by sialidase digestion. WGA-, Con-A-, UEA-I-, RCA-I-, PNA- and SBA-reactive sites were distributed differently in the porcine ZP. Sialidase digestion increased the positivity obtained with RCA-I and it was necessary to promote PNA and SBA reactivity. These results indicated that the ZP contained N-acetylglucosamine, a-mannose, a-fucose, b-Gal-(1-4)GlcNAc, b-Gal- (1-3)GalNAc, b-GalNAc and sialic acid residues. We also observed the presence of vesicles in both the ooplasm and granulosa cells, showing a similar lectin binding pattern to that of the ZP, thus suggesting that the oocyte and granulosa cells are the site of synthesis of ZP glucidic determinants.

Glycohistochemistry of the zona pellucida of developing oocytes in the rabbit and hare.

Lagomorpha are often used as animal models in reproductive experiments. The aim of the present study was to examine the glycoconjugate modifications occurring mainly in the zona pellucida during oocyte growth in the rabbit and hare, using a battery of lectins combined with sialidase digestion and chemical treatments. This histochemical approach made it possible to identify sulpho- and asulpho-carbohydrates in the terminal and/or subterminal position linked to sialic acid residues. The lectins that stained the zona pellucida of both species most effectively were SBA, PNA and WGA, indicating the presence of beta-D-N-acetylgalactosamine, beta-D-galactosamine and N-acetylglucosamine residues. The differences in the glucidic residue content and in their spatial distribution that depended on the species and stage of follicle development were also detected.

Localization of the lectin reactive sites in adult and prepubertal horse testes.

The testes of prepubertal and adult horses were investigated using 10 horseradish peroxidase conjugated lectins combined with sialidase digestion and potassium hydroxide treatment, to localise the oligosaccharide sequences of glycoconjugates during spermatid maturation. In adult animals, the lectins showed a variable affinity for spermatids and Sertoli cell apical extensions. Soybean agglutinin (SBA), peanut agglutinin (PNA), Ricinus communis agglutinin (RCA-I) and wheat germ agglutinin (WGA) bound to the acrosomal structures of spermatids, whereas Griffonia simplicifolia agglutinin (GSA-II) labelled these structures only during Golgi and cap phases. These results suggested that glycoproteins of mature acrosomes contain both N- and O-linked oligosaccharides and that these carbohydrate chains undergo modifications during spermiogenesis. Sialic acid residues were not detected throughout the acrosomal development. The lectin binding pattern of Sertoli cells was very similar to that of acrosome of spermatids during the maturation phase. In sexually immature horses, only the degenerated germinal cells and the Leydig cells showed reactivity towards lectins. The first cells reacted with SBA and Dolichos biflorus agglutinin (DBA), the latter with SBA, PNA, WGA, GSA-II, Canavalia ensiformis agglutinin (ConA), Lens culinaris agglutinin (LCA) and also with DBA after sialidase digestion.

Variations in lectin-binding on the zona pellucida during oocyte growth in some wild ungulates.

The aim of the present study was to examine the glycoconjugate modifications occurring in the zona pellucida during oocyte growth in fallow, red and roe deer using a battery of lectins combined with sialidase digestion and chemical treatments. This histochemical approach allowed us to sequence the oligosaccharidic side chains of the zona pellucida glycoproteins in these wild ungulates. The most effective lectins in the zona pellucida of these species were SBA, PNA, RCA-I GSA-IB4, and WGA, indicating the presence of beta-D-N-Acetylgalactosamine, beta-D-Galactose, alpha-D-Galactose and N-Acetylglucosamine residues. Additionally, sialic acid moieties were demonstrated. We also observed differences in the glycosidic residue content and in their spatial distribution, depending on the species and stage of follicle development.