Home About us Contact
|
Home About us Contact | ||
|
|
||
Shell Gland (shell + gland)
Selected AbstractsA histochemical study of the reproductive structures in the flatworm Dugesia leporii (Platyhelminthes, Tricladida)INVERTEBRATE BIOLOGY, Issue 2 2006Gavina Corso Abstract. The functional morphology and the topographic distribution of tissues in the reproductive system of specimens of Dugesia leporii, an endemic Sardinian free-living planarian, are investigated. Data are provided on the nature of epithelial and glandular secretions, spermatophores, and cocoons by histochemistry, light microscopy, and scanning electron microscopy. All secreting epithelial cells produce strongly acidic sulfated glycoproteins. Glandular cells secrete strongly acidic sulfated glycoproteins or keratohyalin-like material in the penis bulb, and prekeratin-like material in atrial glands. Secretions of the bursa copulatrix may be involved in the activation of sperm while material produced by the bursa canal and oviducts probably serves to propel spermatophores or sperm and eggs. Mucous secretion of the seminal vesicle may serve to dilute and activate sperm before copulation. The viscous secrete of the ejaculatory duct and vasa deferentia may play a protective role to maintain sperm viability. Materials produced by the penis papilla and atrium probably lubricate the epithelial surface. The bilayered wall of spermatophore made of keratohyalin-like material and strongly acidic sulfated glycoproteins is produced by two gland types of the penis bulb. The bilayered shell of cocoon made of prekeratin-like and keratohyalin-like materials is secreted by both atrial glands and vitelline cells. The cocoon stalk is made of keratohyalin-like material produced by cement glands. Shell glands, producing GAG, are not involved in cocoon formation, but they may be implicated in the dilution and activation of seminal material to favor sperm movement toward the oviducts. [source] Macroscopic and Microscopic Anatomy of the Oviduct in the Sexually Mature Rhea (Rhea americana)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 3 2008R. C. Parizzi Summary The morphological characteristics of the oviduct of 12 sexually mature rheas (Rhea americana) were studied. Only the left oviduct is developed as a long tube with a length of 122 ± 23.1 cm, and is subdivided into infundibulum (15.2 ± 4.0 cm), magnum (63.3 ± 9.4 cm), isthmus (5.6 ± 3.1 cm), uterus (16.0 ± 4.2 cm) and vagina (11.5 ± 1.4 cm). The mucous membrane of the oviduct, as a whole, possesses luminal folds covered by ciliated columnar epithelium with secretory cells. The infundibulum part presents a cranial opening with thin and long fimbriae with few tubular glands in caudal tubular portion. In the magnum, the largest portion of the oviduct, the folds are thicker and are filled with tubular glands. The isthmus is short and presents less bulky folds and a few tubular glands. A bag-shaped uterus in the cranial area shows thin folds, and in the caudal region (shell gland) more ramified folds with few tubular glands. The vagina has long luminal folds and a thick muscular tunic; no glands with sperm-storage characteristics have been observed. In conclusion, the oviduct in sexually mature rhea has morphological similarities with the other species of birds already described; however it presents its own characteristics to produce a big egg. [source] Polymorphisms in eggshell organic matrix genes are associated with eggshell quality measurements in pedigree Rhode Island Red hensANIMAL GENETICS, Issue 1 2009I. C. Dunn Summary Novel and traditional eggshell quality measurements were made from up to 2000 commercial pedigree hens for a candidate gene association analysis with organic eggshell matrix genes: ovocleidin-116, osteopontin (SPP1), ovocalyxin-32 (RARRES1), ovotransferrin (LTF), ovalbumin and ovocalyxin-36, as well as key genes in the maintenance and function of the shell gland [estrogen receptor (ESR1) and carbonic anhydrase II (CAII)]. Associations were found for (i) ovalbumin with breaking strength and shell thickness; (ii) ovocleidin-116 with elastic modulus, shell thickness and egg shape; (iii) RARRES1 with mammillary layer thickness; (iv) ESR1 with dynamic stiffness; (v) SPP1 with fracture toughness and (vi) CAII with egg shape. The marker effects are as large as 17% of trait standard deviations and could be used to improve eggshell quality. [source] Expression and localization of estrogen receptors , and , mRNA in medullary bone of laying hensANIMAL SCIENCE JOURNAL, Issue 2 2006Tomohiko IMAMURA ABSTRACT The aim of this study was to observe the expression and localization of estrogen receptor (ER) , and ER , mRNA in the medullary bone of laying hens. First, medullary bone, liver, kidney, and shell gland of the oviduct tissues were dissected from laying hens. Then, the total cellular RNA was isolated from each tissue specimen, and the ER , and ER , mRNA expression was observed using semiquantitative RT-PCR. Second, the localization of ER , mRNA in the medullary bone was detected with in situ hybridization using digoxigenin-11-UTP-labeled cRNA probes. As a result, the expression of ER , mRNA was higher than that of ER , mRNA in the medullary bone, liver, and shell gland of the oviduct from laying hens. In the kidney, ER , mRNA expression was lower than that of ER , mRNA. The expression pattern of ER , and ER , mRNA of the medullary bone was similar to that of the shell gland of the oviduct. Moreover, ER , mRNA was intensively expressed in osteoblasts on the medullary bone surface and bone marrow stromal cells but was not expressed in osteoclasts. These results suggest that in medullary bone, estrogen action may be regulated not by ER , but by ER ,. [source] | ||||||||||