Evidence for a species-specific barrier to sperm transport within the vagina of the chicken hen

Following their insemination into the vagina of chicken hens, turkey spermatozoa did not appear to reach the ovum within the upper magnum or infundibulum and were only occasionally found within the sperm storage tubules at the uterovaginal junction. Turkey spermatozoa were able to populate chicken uterovaginal sperm storage tubules as (or more) efficiently as fowl spermatozoa in uterovaginal junction tissue in vitro. They also populated uterovaginal junction sperm storage tubules in vivo after insemination directly into the uterovaginal region. Thus, a barrier to foreign spermatozoa appears to exist within the vagina of the chicken and not at the level of the uterovaginal junction sperm storage tubules. The nature of this barrier is not known; however it can be shown that while chicken and turkey spermatozoa have similar morphological features and motility characteristics, they have distinct surface antigenicity. Recognition of surface antigenicity by a localised immunological mechanism may be the basis of sperm selection within the hens vagina.     

Analysis of gene expression profiles of gastric normal and cancer tissues by SAGE

In an attempt to understand the molecular bases of gastric cancer progression, we have analyzed the differentially expressed genes in gastric cancer by SAGE. Four SAGE cDNA tag libraries were constructed from two sets of gastric cancer and normal tissues and 241,127 tags were obtained. By comparing the tags from cancer and normal tissues, 414 differentially expressed tags, representing 383 genes, were identified in cancer tissues (p 相似文献   

Effects of different artificial insemination techniques and sperm doses on fertility of normal mares and mares with abnormal reproductive history

The effects of different artificial insemination (AI) techniques and sperm doses on pregnancy rates of normal Hanoverian breed mares and mares with a history of barrenness or pregnancy failure using fresh or frozen-thawed sperm were investigated. The material included 187 normal mares (148 foaling and 39 young maiden mares) and 85 problem mares with abnormal reproductive history. Mares were randomly allotted into groups with respect to AI technique (routine AI into the uterine body, transrectally controlled deep intracornual AI ipsilateral to the preovulatory follicle, or hysteroscopic AI onto the uterotubal junction ipsilateral to the preovulatory follicle), storage method of semen (fresh, frozen-thawed), AI volume (0.5, 2, 12 ml), and sperm dose (50 x 10(6) or 300 x 10(6) progressively motile sperm (pms) for fresh semen and 100 or 800 x 10(6) frozen-thawed sperm with >35% post-thaw motility). The mares were inseminated once per cycle, 24 h after hCG administration when fresh semen was used, or 30 h for frozen-thawed semen. Differences in pregnancy rates between treatment groups were analyzed by Chi-squared test, and for most relevant factors (insemination technique, mare, semen, and stallion) expectation values and confidence intervals were calculated using multivariate logistic models. Neither insemination technique, volume, sperm dose, nor mare or stallion had significant effects (P > 0.05) on fertility. Type of semen, breeding mares during foal heat, and an interaction between insemination technique, semen parameters, and mares did have significant effects (P < 0.05). In problem mares, frozen semen AI yielded significantly lower pregnancy rates than fresh semen AI (16/43, 37.2% versus 25/42, 59.5%), but this was not the case in normal mares. In normal mares, hysteroscopic AI with fresh semen gave significantly (P < 0.05) better pregnancy rates than uterine body AI (27/38, 71% versus 18/38, 47.3%), whereas in problem mares this resulted in significantly lower pregnancy rates than uterine body AI (5/15, 33.3% versus 16/19, 84.2%). Our results demonstrate that for problem mares, conventional insemination into the uterine body appears to be superior to hysteroscopic insemination and in normal mares, the highest pregnancy rates can be expected by hysteroscopic insemination.     

Changes in the expression of estrogen receptor mRNA in the utero-vaginal junction containing sperm storage tubules in laying hens after repeated artificial insemination

The objective was to determine whether expression of estrogen receptor (ER) mRNA in the utero-vaginal junction (UVJ) of laying hens was altered after repeated artificial insemination (AI). Semi-quantitative RT-PCR was used to determine the expression of mRNA of the two types of receptor, ERalpha and ERbeta. Only ERalpha mRNA was expressed in all segments of the oviducts of both virgin and artificially inseminated birds, whereas ERbeta mRNA was expressed in ovarian follicles but not in the oviduct. The expression of ERalpha mRNA in the UVJ was significantly decreased after repeated AI, whereas that in the uterus was not significantly different between virgin and inseminated birds. Since estrogen may be involved in maintaining the sperm storage function of sperm storage tubules, the decreased expression of ERalpha mRNA in the UVJ after repeated AI may contribute to reduced fertility in these birds.     

Serial analysis of gene expression in the silkworm, Bombyx mori

The silkworm Bombyx mori is one of the most economically important insects and serves as a model for Lepidoptera insects. We used serial analysis of gene expression (SAGE) to derive profiles of expressed genes during the developmental life cycle of the silkworm and to create a reference for understanding silkworm metamorphosis. We generated four SAGE libraries, one from each of the four developmental stages of the silkworm. In total we obtained 257,964 SAGE tags, of which 39,485 were unique tags. Sorted by copy number, 14.1% of the unique tags were detected at a median to high level (five or more copies), 24.2% at lower levels (two to four copies), and 61.7% as single copies. Using a basic local alignment search tool on the EST database, 35% of the tags matched known silkworm expressed sequence tags. SAGE demonstrated that a number of the genes were up- or down-regulated during the four developmental phases of the egg, larva, pupa, and adult. Furthermore, we found that the generation of longer cDNA fragments from SAGE tags constituted the most efficient method of gene identification, which facilitated the analysis of a large number of unknown genes.     

Extract‐SAGE: An integrated platform for cross­analysis and GA­based selection of SAGE data

Serial analysis of gene expression (SAGE) is a powerful quantification technique for gene expression data. The huge amount of tag data in SAGE libraries of samples is difficult to analyze with current SAGE analysis tools. Data is often not provided in a biologically significant way for cross‐analysis and ‐comparison, thus limiting its application. Hence, an integrated software platform that can perform such a complex task is required. Here, we implement set theory for cross‐analyzing gene expression data among different SAGE libraries of tissue sources; up‐ or down‐regulated tissue‐specific tags can be identified computationally. Extract‐SAGE employs a genetic algorithm (GA) to reduce the number of genes among the SAGE libraries. Its representative tag mining will facilitate the discovery of the candidate genes with discriminating gene expression.     

The relationship of infertility to antibody production in the uterovaginal sperm storage tubules of turkey breeder hens

Oviductal tissue from fertile and infertile turkey breeder hens was stained immuno-histochemically to test for the presence of antibody positive cells. Relatively infertile turkey hens (< 50% fertility) were found to have antibody positive cells within the uterovaginal sperm storage tubule epithelium, while fertile turkey hens (> 90% fertility) had no antibody positive cells. Data suggest a local immune response to spermatozoa exists in the uterovaginal sperm storage tubules of the turkey hen which may have a detrimental effect on fertility.     

Generation of high-quantity and quality tag/ditag cDNAs for SAGE analysis

The serial analysis of gene expression (SAGE) technique is an important tool for genome-wide gene expression analysis. However, the requirement of a large amount of mRNA for the analysis and the difficulties in generating high-quality tag and ditag fragments for the construction of a SAGE library often interfere with the successful performance of the SAGE technique. We developed two procedures to solve these issues: (i) introducing low-cycle PCR amplification of the 3' cDNA before the BsmFI digestion of the 3' cDNAs and (ii) gel purifying the BsmFI-released tag fragments before ditag formation. These modifications provide a large quantity of initial 3' cDNAs and high-quality tags and ditags for the construction of SAGE libraries.     

Correct identification of genes from serial analysis of gene expression tag sequences

SAGE (serial analysis of gene expression) is a remarkable technique for genome-wide analysis of gene expression. It is crucial to understand the extent to which SAGE can accurately indicate a gene or expressed sequence tag (EST) with a single tag. We analyzed the effect of the size of SAGE tag on gene identification. Our observation indicates that SAGE tags are in general not long enough to achieve the degree of uniqueness of identification originally envisaged. Our observations also indicate that the limitation of using SAGE tag to identify a gene can be overcome by converting SAGE tags into longer 3' EST sequences with the generation of longer cDNA fragments from SAGE tages for gene identification (GLGI) method.