Universidad de Murcia. Departamento de Biología Celular e Histología
Abstract
This work studies the morphological changes
taking place in the Dama dama rumen during prenatal
development using histomorphometrics, surface microstructure and immunohistochemistry analysis as well as
carrying out a comparative analysis of this species with
other wild (red deer) and domestic-type ruminants. A
total of 25 fallow deer embryos and fetuses were used,
from the first stage of prenatal life until birth. The
appearance of the rumen from the primitive gastric tube
was observed at 51 days of prenatal life (CRL 3 cm,
21% gestation). By 57 days (CRL 4.3 cm, 24%
gestation) the ruminal wall comprised three layers: an
internal epithelial layer, a middle layer of pluripotential
blastemic tissue and an external layer or serosa. Ruminal
pillars were visible at 72 days (CRL 6 cm, 30%
gestation), and by 85 days (CRL 7.2 cm, 35% gestation)
ruminal papillae were starting to appear. Under scanning
electron microscopy, by 80 days (CRL 7 cm, 33%
gestation) small ruminal papillae were observed
protruding from the surface. Morphometric results
showed accelerated growth of the epithelial layer and the
tunica muscularis at 180 days (75% gestation). By
contrast, the growth-rate of the lamina propria and
submucosa declined from the early embryonic stages
until birth. The serosa maintained a steady rate of growth
until birth. Neuroendocrine cells (synaptophysin) were
detected at 85 days (CRL 7.2 cm CRL, 35% gestation),
while glial cell markers (glial fibrillary acidic protein
and vimentin) were found at 108 days (CRL 31 cm, 45%
gestation) and 63 days (CRL 4.4 cm, 26% gestation)
respectively. Neuropeptide Y and vasoactive intestinal
polypeptide were detected immunohistochemically at
180 days (CRL 33 cm, 75% gestation) and 192 days
(CRL 35 cm, 80% gestation) respectively. In comparison
to other wild and domestic-type ruminants,
histomorphogenesis of the rumen in Dama dama was
similar to that reported in red deer and goats, but rather
slower than that observed for sheep or cattle