Pregnancy-associated glycoprotein (PAG) family: transcripts and gene amplicons in camelids.

In this study, the placental localization of PAG-like transcripts and genomic existence of PAG-like amplicons in new-world (Lp, Lama pacos, alpaca) and old-world camelids (Cb, Camelus bactrianus, bactrian; Cd, Camelus dromedarius; dromedary) are reported for the first time. Sections of Lp (150-347 days post coitum), Cd (43-90 cm crown-rump length) and Cb (term) placentas were used for heterologous (ht; cross-species) autoradiographic in situ hybridization (aISH) with single-stranded diagnostic (antisense) or control (sense) [alpha-(35)S]dATP-labeled 323 nt porcine PAG8 (pPAG8) cDNA probes produced by asymmetric PCRs. The aISH with antisense (35)S-pPAG8 probe identified camelid PAG-like (LpPAG, CbPAG and CdPAG) mRNA expression restricted to chorionic epithelium cells within placentas of camelids. In addition, genomic DNA (gDNA), isolated from placental sections were used as templates for camelid PAG-like gene amplicon production by PCR. Specificity of the obtained multiple camelid gDNA PAG-like amplicons was confirmed by double ht-Southern hybridizations with [alpha-(32)P]dATP-labeled 611 bp pPAG5 and pPAG10 double-stranded cDNA probes. The double ht-Southern hybridizations of camelid gDNA amplicons (with pPAG5 and -10 probes) allowed the identification of length-polymorphism of LpPAG, CbPAG and CdPAG genes, coding catalytically active and potentially inactive forms. Such an application of porcine PAG probes may be advantageous for future identification of still undiscovered PAG-like families in other eutherian species.

Microvascular architecture of the fetal cotyledons in water buffaloes (Bubalus bubalis) during different stages of pregnancy.

To elucidate the morphological background of physiological differences between bovine and buffalo gestation forty-two placentae ranging from the 3rd to 10th month of pregnancy were used to study the microvascular architecture of the fetal cotyledons in the buffalo. The tissues were prepared for light and scanning electron microscopy by paraformaldehyde fixation and corrosion casting of the fetal cotyledonary vascular system. Histology and vascular casts revealed the buffalo fetal cotyledons to consist of a series of conical villous trees changing from a wide to slender shape during pregnancy, and with a base strictly facing the fetal side. The branches of these trees, intermediate and terminal villi, projected radially from the stem, thus representing a rough type of villous tree. A second type of tree lacked these branches and was therefore termed smooth villus. The rough type was most prevalent, and the intermediate and terminal villi showed capillary complexes arranged in stories by the 4th to 5th month of gestation. The stories became broader and denser with the progress of pregnancy (6th to 7th month of gestation), due to extensive growth of new capillaries and simultaneous development of convolutions causing the vascular ridges of the terminal villi to appear bushy. Near term (9th to 10th month) the capillary system became very dense, particularly at the margin of the vascular ridges, leaving only narrow spaces for the corresponding maternal septal tissue. In detail, at its base the trunk of each villous tree contained a single central stem artery which originated from the allantochorionic arterial system, and 1-3 parallel peripheral stem veins. When approaching the cone tip, these vessels branched into new stem arteries and veins, each giving rise to arterioles and venules according to the principle vascularization of the stem villus first, followed by intermediate and terminal villi. The capillary complex of the terminal villi consisted of arterial capillary limbs, capillary loops with sinusoidal dilatations and anastomoses, and venous capillary limbs. The latter converged into venules of terminal and intermediate villi which joined stem veins leading into allantochorionic veins. In conclusion, the fetal vasculature of the buffalo placentome was greatly increased from early pregnancy to near term. This was denoted by the general development of stem villous trees and an increase in the volume and density of the capillary system of the terminal villi, reflecting the increasing need of materno-fetal substance exchange in the buffalo placenta, particularly near term.

Morphological characteristics of the tongue and its papillae in the donkey (Equus asinus): a light and scanning electron microscopical study.

The morphology of the donkey tongue and its papillae were investigated by macroscopy and by light and scanning electron microscopy in ten adult animals (six males and four females). The spatula-shaped tongues measured about 28 cm in length, 4.5 cm in breadth and 3.5 cm in thickness. Samples from different areas of four tongues were grossly examined and pieces were processed for light and scanning electron microscopy. Filiform papillae were distributed mainly on the dorsum of the tongue, being thin and relatively short at the apex, conical and scaly in the main part (triangular zone) of the body, and thin and longer at the caudal part of the body. Few of them were found on the lateral surfaces. Fungiform papillae appeared scattered mainly on the lateral surfaces. They were mostly rounded (about 1.0 mm in diameter), but lobulated forms were also observed. Filiform and fungiform papillae were both completely devoid of taste buds, indicating a more mechanical function. The vallate papillae were 2-3 in number, located at the most caudal part of the body. They were three to four times as large as the fungiform papillae (about 5.6 mm in diameter) each with a wide circular groove around the central bulbous projection. Secondary grooves originating from the primary one were also demonstrated. The vallate papillae contained many taste buds with taste pores opening deeply into the papillary groove. Fine filiform papillae were demonstrated on the bulb-like part of the vallate papillae. The donkey tongue had sinister and dexter well-developed sets of foliate papillae close to the basis of the palatoglossal arch. They were arranged in the form of numerous leaves separated by deep, variably wide grooves and contained a very large number of taste buds. It is believed that the existence of well developed foliate papillae in donkey may substitute the comparatively few vallate papillae in this species.