In vitro evaluation of fresh sperm quality in tomcats: A comparison of two collection techniques

The collection of semen from tomcats by urethral catheterization (CT) after medetomidine administration offers a novel and easy approach to obtain good quality sperm for in vitro fertilization. This study was designed to compare the sperm quality parameters and in vitro fertilizing capacity of CT spermatozoa with those of spermatozoa retrieved after epididymal slicing (EP). Semen was collected in seventeen adult cats by urethral catheterization, after which the cat was orchiectomized. Motility, morphology, plasma membrane integrity, acrosomal status, and in vitro fertilizing capacity of both fresh CT and EP samples were evaluated. The results showed that both total and progressive motility, as well as the percentage of normal spermatozoa, were higher for EP sperm than for CT sperm (P < 0.01). Epididymal sperm had a lower percentage of spermatozoa with an intact acrosome (P < 0.01), while CT sperm contained more spermatozoa with tail abnormalities (P < 0.01). Other morphological parameters, as well as plasma membrane integrity, did not differ (P > 0.05) between CT and EP sperm. Nevertheless, no difference (P > 0.05) in in vitro fertilizing capacity between spermatozoa collected by means of the two different methods was found. In conclusion, semen collection by means of urethral catheterization after medetomidine administration yields fertilization results similar to epididymal slicing, despite the fact that several sperm variables were different. Since this novel catheterization technique is repeatable, is easy to perform and facilitates semen preparation protocols, it may be preferable for routine IVF experiments with fresh spermatozoa.     

Quality and fertilizing ability of electroejaculated cat spermatozoa frozen with or without Equex STM Paste

An optimal protocol for cat semen cryopreservation has not yet been defined. Addition of Equex STM Paste has been tested for epididymal cat spermatozoa but not for ejaculated cat spermatozoa. Furthermore, the effect of Equex STM Paste on fertilizing ability of cryopreserved semen has never been evaluated in that species. Therefore, the aims of the current study were to investigate if addition of Equex STM Paste to a freezing extender for electroejaculated cat (Felis catus) semen would improve postthaw sperm quality and if sperm fertilizing ability after cryopreservation with or without Equex STM Paste was preserved. Semen was collected by electroejaculation and frozen in a Tris-glucose-citrate egg yolk extender supplemented with (0.5% vol/vol) or without Equex STM Paste. In Experiment 1, sperm motility, membrane integrity, and acrosomal status were determined immediately after collection and at 0, 3, and 6 h postthaw. In Experiment 2, frozen semen from the two groups was used for in vitro fertilization (IVF) of in vitro-matured cat oocytes. Cleavage rate was recorded 30 h after IVF, and embryo development was evaluated on Days 6 and 7 of culture. In Experiment 1, the rate of motile spermatozoa after freezing-thawing was higher when Equex STM Paste was added to the freezing extender, but progressive motility score was not influenced (P > 0.05). Sperm membrane integrity was positively affected (P < 0.05) by the addition of the detergent. Intact acrosomes after thawing were similar (P > 0.05) between groups. Even if the decreasing rates of motility and membrane integrity were more rapid in presence of Equex than those in controls, total motility and sperm viability were similar at 3 and 6 h after thawing (P > 0.05). In Experiment 2, there was no difference in fertilizing ability and embryo development between the two groups (P > 0.05). The results of this study demonstrate that the addition of Equex STM Paste in the freezing extender avoids the loss of motile spermatozoa and maintains fertilizing ability of frozen-thawed spermatozoa.     

A systematic study of the development of the airway (bronchial) system of the avian lung from days 3 to 26 of embryogenesis: a transmission electron microscopic study on the domestic fowl, Gallus gallus variant domesticus

In the embryo of the domestic fowl, Gallus gallus variant domesticus, the lung buds become evident on day 3 of development. After fusing on the ventral midline, the single entity divides into left and right primordial lungs that elongate caudally while diverging and shifting towards the dorsolateral aspects of the coelomic cavity. On reaching their definitive topographical locations, the lungs rotate along a longitudinal axis, attach, and begin to slide into the ribs. First appearing as a solid cord of epithelial cells that runs in the proximal-distal axis of the developing lung, progressively, the intrapulmonary primary bronchus begins to canalize. In quick succession, secondary bronchi sprout from it in a craniocaudal sequence and radiate outwards. On reaching the periphery of the lung, parabronchi (tertiary bronchi) bud from the secondary bronchi and project into the surrounding mesenchymal cell mass. The parabronchi canalize, lengthen, increase in diameter, anastomose, and ultimately connect the secondary bronchi. The luminal aspect of the formative parabronchi is initially lined by a composite epithelium of which the peripheral cells attach onto the basement membrane while the apical ones project prominently into the lumen. The epithelium transforms to a simple columnar type in which the cells connect through arm-like extensions and prominently large intercellular spaces form. The atria are conspicuous on day 15, the infundibulae on day 16, and air capillaries on day 18. At hatching (day 21), the air and blood capillaries have anastomosed profusely and the blood-gas barrier become remarkably thin. The lung is well developed and potentially functionally competent at the end of the embryonic life. Thereafter, at least upto day 26, no further consequential structures form. The mechanisms by which the airways in the avian lung develop fundamentally differ from those that occur in the mammalian one. Compared with the blind-ended bronchial system that inaugurates in the mammalian lung, an elaborate, continuous system of air conduits develops in the avian one. Further studies are necessary to underpin the specific molecular factors and genetic processes that direct the morphogenesis of an exceptionally complex and efficient respiratory organ.     

Water loss from eggs of domestic fowl and calcium status of hatchlings

Water balance in eggs of domestic fowl was manipulated by drilling holes (each 3 mm in diameter) through the calcareous layer into the air cell on day 10 of incubation. Water loss between days 0 and 18 averaged 6 g for eggs in the control group (no hole) but increased to 8, 12, and 15 g for eggs with 1, 2, or 3 holes, respectively. Hatching success was 79–87% for eggs with 0–2 holes through the eggshell but only 43% for eggs with three holes. Live mass of hatchlings declined as the number of holes drilled in the eggshell increased, but dry mass of carcasses was unaffected by the treatments. The quantity of Ca²⁺, Mg²⁺, and phosphorus in residual yolks and yolk-free carcasses of hatchlings was not influenced by the amount of water lost from eggs. Plasma Ca²⁺ and Mg²⁺ were elevated in hatchlings from eggs with high rates of water loss. The inability to regulate plasma Ca²⁺ may be a negative consequence of excessive water loss and could contribute to increased mortality of embryos.     

Postnatal development of intra-epithelial leukocytes in the chicken digestive tract: phenotypical characterization in situ

In the present study, we characterized intra-epithelial leukocytes in the digestive tract of chickens during postnatal development. Their phenotype was characterized by monoclonal antibodies in cryostat sections and the numbers of the different cell-types were counted in the epithelium of the esophagus, proventriculus, duodenum, jejunum, cecum, and colon. All intra-epithelial leukocytes bore the leukocyte-common antigen CD45; 35% were T lymphocytes, and 50% bore a B-cell marker. However, no immunoglobulin-bearing cells were detected in the epithelium. Monocytes and macrophages were found only in the epithelium of the esophagus. A remaining population of non-B, non-T, non-monocyte cells (15%) was present in all parts of the digestive tract. The number of intra-epithelial leukocytes was greatest in the duodenum and jejunum, and decreased in the proximal part of the cecum and in the colon. Intra-epithelial leukocytes were only sporadically detected in the proventriculus. The total number of intra-epithelial leukocytes increased until 8 weeks after hatching and then decreased at 18 months. In the esophagus, the total number of intra-epithelial leukocytes changed little during aging. We found that the intra-epithelial leukocytes of chickens and rodents are distinct in that chicken intra-epithelial leukocytes comprise a cell population that bears a B-cell antigen but that lacks surface immunoglobulins.     

Immunocytochemical study of the lung of domestic fowl and pigeon: endocrine cells and nerves

the presence of endocrine cells and nerves in the lung of 2 avian species (Gallus gallus and Columba livia domestica) has been studied by peroxidase-antiper-oxidase (PAP) and avidin-biotin complex (ABC) immunocytochemical methods at the light-microscopic level. Two immunoreactive cell-types have been identified in the epithelium of the primary and secondary bronchi of chick lung: serotonin- and bombesin-immunoreactive cells; and 3 cell-types, namely, serotonin-, bombesin- and CGRP-(calcitonin gene related peptide) immunoreactive cells, have been located in the bronchial epithelium of pigeon lung. Co-localization of 2 different immunoreactivities within the same cell has not been detected. VIP-immunoreactive nerves have been observed in different locations in chick lung.     

亲子典型相关在家蚕育种中的应用

运用典型相关理论分析了家蚕亲代和子代两组数量性状,并对其遗传育种学意义作了探讨。由于亲子典型相关系数在数值上就等于亲子间典型性状的回归系数,所以亲子典型相关系数也代表了亲代典型性状将其遗传特征传递给子代典型性状的能力。典型性状作为多个数量性状的公共因子,在亲子代间具有最大的传递能力,对亲代典型性状进行选择,将具有最大的选择效果和最小的估计误差。     

Immunocytochemical demonstration of somatostatin-containing neurons in the hypothalamus of the domestic mallard

Summary In the hypothalamus of the adult domestic mallard, small to medium-sized perikarya are stained specifically with rabbit antiserum against cyclic somatostatin (PAP technique of Sternberger). The somatostatin-immunoreactive material is located in neurons different from those containing immunoreactive LHRH, vasotocin or mesotocin. Somatostatin-containing perikarya are observed 1) in a chain-like arrangement extending from the area of the median division of the supraoptic nucleus to the caudal end of the paraventricular nucleus; 2) as single cells in the preoptic region; and 3) as a conspicuous formation in the optic tract division of the supraoptic nucleus. In the rostral portion of the median eminence, somatostatin-immunoreactive axons penetrate into the external zone. Fine accessory fiber bundles project to the neural lobe.     

On the tryptic peptides from hemoglobin chains of six carnivores

Summary The amino acid compositions of the tryptic peptides of the following carnivore hemoglobin chains have been determined: gray fox (Urocyon cineroargenteus); raccoon (Procyon lotor); polar bear (Thalarctos maritimus); coati mundi (Nasua nasua) chain; coati mundi (Nasua narica) two chains; cat (Felis catus) chain; and lion (Panthera leo) chain. These provide a basis for future sequencing of these hemoglobins and construction of an evolutionary tree. The specific results are summarized in the following article (Stenzel and Brimhall, 1977).     

Structural and enzymatic studies on the plasma membrane domains and sodium pump enzymes of absorptive epithelial cells in the avian lower intestine

Summary The coprodaeum of the domestic hen maintained on a low-NaCl diet adapts by enhanced sodium transport. This study examines the adaptive response at the single cell and whole organ levels. Surface areas of apical (microvillous) and basolateral plasma membranes of columnar absorptive epithelial cells were estimated by use of ultrastructural stereology. The activities of succinic dehydrogenase (a mitochondrial enzyme) and ouabain-sensitive, potassium-dependent paranitrophenyl phosphatase (a sodium pump enzyme) were determined in tissue homogenates. Sodium, potassium-ATPase (pump enzyme) activity in cell membranes was localized by ultrastructural cytochemistry. Apical and basolateral membranes responded differently. In high-NaCl hens, the membrane signature of the average cell was 32 m² (apical), 932 m² (lateral) and 17 m² (basal). Cells from low-NaCl hens had more apical membrane (49 m² per cell) but essentially the same area of basolateral membrane. However, total surfaces per organ were greater for all membranes. Sodium pump enzymes were localized in basolateral membranes. Enzyme activities per unit mitochondrial volume and per unit basolateral membrane surface were higher in low-NaCl birds. These findings are discussed in the context of known mechanisms of transcellular sodium transport via apical ion channels and basolateral pumps.