Sperm storage within the oviduct of turtles

Tubules containing sperm were identified by light microscopy in the oviducts from 11 species of turtles representing six different families. Sperm storage tubules were found in a small region of the posterior portion of the egg albumin-secreting section of the oviduct located between the infundibulum and the uterus. This location of storage tubules, midway between the ovary and vagina, is unique among vertebrates. Ducts, restricted to the posterior albumin region, connect the tubules to the oviduct lumen, allow entrance of sperm to the tubules. Sperm were identified in tubules of female turtles isolated from males for as long as 423 days.     

Neonatal phytoestrogen exposure alters oviduct mucosal immune response to pregnancy and affects preimplantation embryo development in the mouse

Treatment of neonatal mice with the phytoestrogen genistein (50 mg/kg/day) results in complete female infertility caused in part by preimplantation embryo loss in the oviduct between Days 2 and 3 of pregnancy. We previously demonstrated that oviducts of genistein-treated mice are "posteriorized" as compared to control mouse oviducts because they express numerous genes normally restricted to posterior regions of the female reproductive tract (FRT), the cervix and vagina. We report here that neonatal genistein treatment resulted in substantial changes in oviduct expression of genes important for the FRT mucosal immune response, including immunoglobulins, antimicrobials, and chemokines. Some of the altered immune response genes were chronically altered beginning at the time of neonatal genistein treatment, indicating that these alterations were a result of the posteriorization phenotype. Other alterations in oviduct gene expression were observed only in early pregnancy, immediately after the FRT was exposed to inflammatory or antigenic stimuli from ovulation and mating. The oviduct changes affected development of the surviving embryos by increasing the rate of cleavage and decreasing the trophectoderm-to-inner cell mass cell ratio at the blastocyst stage. We conclude that both altered immune responses to pregnancy and deficits in oviduct support for preimplantation embryo development in the neonatal genistein model are likely to contribute to infertility phenotype.     

A quantitative comparison of the passage of capacitated and uncapacitated hamster spermatozoa through the uterotubal junction.

Female hamsters were artificially inseminated at the time of ovulation with an equal concentration and volume of capacitated sperm suspension in one uterus and uncapacitated sperm suspension in the contralateral uterus. When oviducts were examined 3.5-4.0 h after insemination, a significantly (paired t-test, p less than 0.05) lower number of spermatozoa were found in the oviduct from the side inseminated with capacitated sperm suspension compared to the side inseminated with uncapacitated sperm suspension. The reduction in the number of spermatozoa entering the oviduct on the side inseminated with capacitated sperm suspension was particularly evident when nearly all the spermatozoa in the suspension were hyperactivated. These results suggest that hamster spermatozoa require a progressive linear type of motility pattern to pass efficiently through the uterotubal junction and that under normal conditions in vivo, fertilizing spermatozoa initiate hyperactivated motility after entering the oviduct.     

斑衣蜡蝉雌性生殖系统超微结构

【目的】明确斑衣蜡蝉Lycorma delicatula雌成虫生殖系统整体形态及超微结构特征,为蜡蝉总科昆虫分类及系统发育探讨提供更多形态学证据。【方法】采用光学显微镜与透射电子显微镜,观察斑衣蜡蝉雌成虫生殖系统整体形态和各主要器官的超微结构。【结果】斑衣蜡蝉雌成虫生殖系统主要包括1对卵巢、1个中输卵管、1个交配囊、1个交配囊管、1个前阴道、1个后阴道、1个受精囊、1个受精管和2根受精囊附腺。卵巢为端滋式,由14根卵巢小管组成,卵室由固有膜、滤泡细胞和卵细胞组成,卵巢小管中的滋养细胞清晰可见;中输卵管位于前阴道基部,由中输卵管腔、上皮细胞、肌肉鞘和基膜组成;交配囊膨大呈圆球状,囊壁由上皮细胞、肌肉层和基膜组成;交配囊管呈圆柱状,连接交配囊和后阴道,由肌肉鞘、上皮细胞层和管腔组成;前、后阴道超微结构相似,主要由肌肉鞘、基膜、上皮细胞和管腔组成,但后阴道上皮细胞细胞核周围存在分泌颗粒,且管腔内有大量微绒毛,而前阴道壁内包含有大量囊泡结构;受精管从中输卵管末端延伸至受精囊,由基膜、厚层肌肉鞘和管腔组成;受精囊为受精管近末端略膨大的囊状结构,由肌肉鞘、基膜、上皮细胞和囊腔构成;雌性受精囊附腺着生于受精囊末端,为均匀的螺旋管状,主要由肌肉层、上皮细胞层和附腺中心管腔组成。【结论】斑衣蜡蝉雌性生殖系统与已报道的蜡蝉总科其他类群的雌性生殖系统结构相似,但卵巢小管数目有差异;蝉亚目中不同总科雌成虫雌性附腺与受精囊附腺的形态特征存在明显区别;斑衣蜡蝉雌性生殖系统超微结构与叶蝉总科和沫蝉总科昆虫也存在部分差异。这些差异是否可以作为头喙亚目高级阶元的划分依据仍有待于进一步研究。     

Internal reproductive organs of the female humpbacked fly,Megaselia scalaris Loew (Diptera : Phoridae)

The female reproductive system of the humpbacked fly Megaselia scalaris Loew (Diptera : Phoridae) was examined in whole mount preparations and serial sections. The system includes 2 ovaries, paired lateral oviducts, a common oviduct, and a genital chamber, opening externally through a gonopore, anteriad and ventrad to the anus. The ducts of the 2 accessory glands open independently into the dorsal region of the genital chamber. The terminal duct of a 2-armed spermatheca joins the right posterior and ventral wall of the genital chamber, immediately inside the gonopore. Passing dorally, the spermathecal duct lies immediately ventral to the duct of the right accessory gland. A short distance posteriad, it divides into two branches, each supplying an arm of the spermatheca. The genital chamber extends both anteriorly and posteriorly from its junction with the common oviduct, creating anterior and posterior compartments. In the right lateral wall of the genital chamber, a distinctive loop-shaped thickening (plate) resembles a darkened thread when it is observed through the integument. Features likely to have taxonomic utility include the posterior and ventral location of the terminal portion of the spermathecal duct; and the asymmetrically arranged, loop-shaped plate.     

Cytosolic progesterone receptors in the oviducts of reproductively active and quiescent turkeys (Meleagris gallopavo)

Cytosolic progesterone receptors (PRcs) from the reproductive tract of the female turkey were analyzed by high-performance liquid chromatography using a diethylaminoethyl (DEAE) ion-exchange column. PRcs from oviduct tissue of laying, incubating, photorefractory and short-day turkey hens were compared. In general, three types of PRcs were identified: Receptor I, a partially displaceable species that was eluted at a 0.13 M salt concentration; and Receptors II and III, which were two specific binding species eluting at 0.23 M and 0.26 M, respectively. In the subdivided tissue from the laying hen oviduct, Receptor I was the major PRc species of the isthmus and Receptor III was the only receptor present in the uterus. The infundibulum and magnum each contained a small amount of Receptor II and a substantial amount of Receptor III. The whole oviduct of incubating hens contained a greater proportion of Receptor I than Receptor II or III, and these last two receptor types were present in equal quantity. The whole oviduct of the short-day hens had an equal distribution of the three receptor types. In the presence of sodium molybdate, an inhibitor of phosphatase and protease, only one sharp Receptor II species was seen in the magnum and uterus of the laying hen oviduct and in the whole oviducts of incubating and short-day hens. The transformation of Receptor II to Receptor III in the absence of sodium molybdate was facilitated by the aging of cytosol at 0-4 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)     

Chlamydiae in oviducts and uteri of repeat breeder pigs

Chlamydial infections of the genital organs cause reproductive failure in female pigs, and the uterus is recognized a target tissue for an infection. In contrast, information on the effect of chlamydiae on the porcine oviduct is patchily and inconclusive, although the bacteria are known to cause severe tubal defects in humans and laboratory animals. The aim of this study was to examine the segments ampulla (A), isthmus (I) and utero-tubal junction of the left (n=20) or both (n=22) oviducts, and uteri (U) from 42 culled repeat breeder pigs for chlamydiae using ompA-PCR, partial ompA gene sequencing, immunohistochemistry (IHC) and microscopy of tissue specimens for histopathology. As revealed by PCR, among a total of 26 chlamydia-positive females, 19 were tested positive in one or more segments of one or both oviducts, 14 were found positive in the uterus, and concomitant infections of both organs were observed in 7 of them. Sequencing of 33 PCR products revealed the following chlamydial species: Chlamydophila (Cp.) psittaci (n=18), Cp. abortus (n=2), Chlamydia (C.) suis (n=10), and C. trachomatis (n=3). Immunopositive staining was observed within the surface epithelium (in A, I, U), stromal tissue (in I, U) and muscular layer (in A, I, U). A total of 24 females had inflamed oviductal segments (in A and/or I) and 36 inflamed uteri. However, there was no relationship between histopathology and results of PCR or IHC. In conclusion, chlamydiae were found to infect oviducts and uteri of pigs. Further studies are required to clarify whether chlamydial infection causes specific histopathology and alters tubal function.     

Sequential oogenesis is controlled by an oviduct factor in the locusts Locusta migratoria and Schistocerca gregaria: Overcoming the doctrine that patency in follicle cells is induced by juvenile hormone

In insects that lay eggs in large clutches, yolk accumulation in each of the many ovarioles is restricted to the basal (terminal) oocyte, the one closest to the lateral oviduct. All succeeding (subterminal) oocytes remain small until the terminal oocytes finished their development and were ovulated into the oviduct. The major step regulating yolk uptake by terminal oocytes is the formation of gaps between cells of the follicle layer, a process termed patency. In the migratory as well as in the desert locust, patency is induced by a Patency Inducing Factor (PIF) produced by the lateral oviducts. PIF is secreted in all regions of the lateral oviducts and interacts with the basal follicle cells via the pedicel, a fine duct that connects an ovariole with the oviduct. By this mechanism, patency is triggered in the follicle cells of the terminal oocyte only, restricting yolk accumulation to the oocytes next to ovulation. In contrast to the previous hypothesis, juvenile hormone (JH) is not necessary to induce patency, rather JH amplifies the effect of PIF.     

Histological observation of the urogenital papillae in the bi-directional sex-changing gobiid fish, Trimma okinawae

The gobiid fish Trimma okinawae changes its sex bi-directionally according to its social status. Morphological changes in the urinogenital papillae (UGP) of this fish have been reported during sex change. However, there have been no detailed observations of such changes. Here, we histologically examined the UGP structure of male- and female-phase fish. UGPs of fish in female and male phase contained both oviducts and sperm ducts. Both ducts were coalesced into one duct within the posterior region of the UGP. Female-phase fish had many longitudinal folds in the hypertrophied tunica mucosa of the oviduct, which was found to be responsible for the transport of eggs and the removal of follicular cells from the oocyte. In contrast, male-phase fish had an immature oviduct and a mature sperm duct in the UGP. In the male-phase fish, the co-existence of spermatozoa and fibrillar secretions was observed in the sperm duct during spermiation.     

长足大竹象生殖系统的形态解剖研究

解剖研究了长足大竹象雌雄虫牛殖系统的构造.该虫的雌性生殖系统包括一对卵巢、一对侧输卵管、中输卵管、交配囊、受精囊、生殖腔、产卵器;雄性生殖系统由一对睾九、一对输精管、一对附腺、射精管和交配器组成.     

Spontaneous and neurally evoked contractions of visceral muscles in the oviduct of Locusta migratoria

The oviducts of Locusta migratoria are innervated by a pair of nerves which arise from, the seventh abdominal ganglion. A distinctive network of striated muscle fibres occurs in the oviducts. The lateral oviducts and common oviduct consist of an inner circular layer of muscle and an outer longitudinal layer of muscle. At the junction of the lateral and common oviduct an additional thin longitudinal layer is found adjacent to the basement epithelium. The oviducts contracted spontaneously when isolated from the central nervous system. These myogenic contractions took the form of peristaltic contractions in the lateral oviduct, and intermittent phasic-like contractions of the posterior regions of the lateral oviduct and the common oviduct. These phasic-like contractions were associated with individual complex potentials recorded extracellularly from the muscle fibres. In locusts that had been interrupted in the process of egg laying, there were large-amplitude action potentials, firing in a bursting pattern, in the oviducal nerves. These large action potentials were absent in locusts that had not been egg-laying. These action potentials were associated with both bioelectric potentials and mechanical events in the posterior region of the lateral oviduct and the common oviduct. Electrical stimulation of the oviducal nerve mimicked the effects of spontaneous action potentials, resulting in the appearance of monophasic potentials and contractions. The contractions were graded and dependent upon both frequency and duration of stimulation. It is concluded that the oviducts of Locusta are both myogenic and neurogenic. The role of these contractions in oviposition is discussed.     

Visualizing Molecular Functions and Cross-Species Activity of Sex-Peptide in Drosophila

The Drosophila melanogaster sex-peptide (melSP) is a seminal fluid component that induces postmating responses (PMR) of females via the sex-peptide receptor (SPR) . Although SP orthologs are found in many Drosophila species, their functions remain poorly characterized. It is unknown whether SP functions are conserved across species or rather specific to each species. Here, we developed a GFP-tagged melSP (G-SP) and used it to visualize cross-species binding activity to the female reproductive system of various species. First we demonstrated that ectopically expressed G-SP induced PMR in D. melanogaster females and bound to the female reproductive system, most notably to the common oviduct. No binding occurred in the females lacking SPR, indicating that G-SP binding was dependent on SPR. Next we tested whether G-SP binds to the common oviducts from 11 Drosophila species using dissected reproductive tracts. The binding was observed in six species belonging to the D. melanogaster species group, but not to those outside the group. Injection of melSP reduced the receptivity of females belonging to the D. melanogaster species group, but not of those outside the group, being consistent with the ability to bind G-SP. Thus the SP-mediated PMR appears to be limited to this species group. SPR was expressed in the oviducts at high levels in this group; therefore, we speculate that an enhanced expression of SPR in the oviduct was critical to establish the SP-mediated PMR during evolution.     

Functional morphology of the female reproductive apparatus of Stephanitis pyrioides (Heteroptera,Tingidae): A novel role for the pseudospermathecae

At mating, female insects generally receive and store sperm in specific organs of their reproductive tract called spermathecae. Some Heteroptera, such as Cimicomorpha, lack a true spermatheca; some have receptacles of novel formation where sperm cells can transit or be stored. In Tingidae, there are two sac‐like diverticula, the “pseudospermathecae,” each at the base of a lateral oviduct, which previously were considered to function as spermathecae. However, this role has never been documented, either by ultrastructural studies or by observations of sperm transit in the female reproductive tract. In this article, we investigate the morphology and the ultrastructure of the female reproductive apparatus in the economically important tingid species Stephanitis pyrioides, focusing our attention on the functional role of the pseudospermathecae in an evolutionary perspective. Each ovary consists of seven telotrophic meroistic ovarioles, the long pedicels of which enlarge into a bulb‐like structure near the terminal oocyte. The ovarioles flow into two long lateral oviducts, which join to form a very short common oviduct. Basally, each lateral oviduct is connected through a short duct to one of two pseudospermathecae. The ultrastructure of the ectodermal epithelium of the pseudospermathecae is dramatically different in sexually immature or mated females. In virgin females, cells delimit a very irregular lumen, filled with a moderately electron‐dense granular material. The large nucleus adapts to their irregular shape, which can have long projections in some regions and be flattened in others. After mating, epithelial cells generally elongate and display an apical layer of microvilli extending beneath the cuticle, often containing mitochondria. In the lumen of the pseudospermathecae there is a dense brownish secretion. No sperm cells were ever found inside this organ. After mating, sperm move upward along the lateral oviducts and the ovarioles, accumulating in the bulb‐like structure of the pedicels, and proceeding into the distal region between the follicle cells surrounding the oocyte and the ovariole wall. The egg, most likely fertilized in the bulb‐like region of the ovariole, moves through the lateral oviduct, entirely enters the pseudospermatheca and is smeared with its secretion just before oviposition. We exclude a function of sperm storage for the pseudospermathecae, and instead suggest a novel role for these organs as reproductive accessory glands. J. Morphol., 2010. © 2009 Wiley‐Liss, Inc.     

Neural and hormonal control of muscular activity of the spermatheca in the locust, Locusta migratoria

The spermatheca in insects is a tubular structure within the female that acts as a repository for spermatozoa deposited by the male during copulation. The spermatozoa remain viable within the spermatheca for extended periods of time, and are then delivered to the site of fertilization during oviposition (egg-laying). Thus, the production of viable offspring is dependent upon the coordination of events associated with fertilization, including the passage of the egg through the lateral and common oviducts and the passage of spermatozoa along the spermathecal duct. The egg and the spermatozoa are propelled along their respective tracts by contractions of the visceral muscles intrinsic to the oviduct and spermatheca. The neural and hormonal control of muscular activity of the locust oviducts has been well reviewed, with more recent studies examining the control over the spermatheca. This review highlights more recent literature, including new data, for neural and hormonal control of muscular activity of the spermatheca of the locust, Locusta migratoria, making reference to examples in other insects where relevant. A variety of neuronal types project to the spermatheca in L. migratoria, and a variety of neuroactive chemicals, including neuropeptides and amines, influence contraction. A comparison is made between the control of oviducts and spermatheca in L. migratoria with regard to their neural substrate and the composition of neuroactive chemicals.     

Sexual differentiation in the CNS of the moth,Manduca sexta. I. Sex and segment-specificity in production,differentiation, and survival of the imaginal midline neurons

We analyzed the development of several sets of postembryonic sex-specific motoneurons in Manduca sexta which belong to a group of homologous lineage of neurons called the imaginal midline neurons (IMNs). Adult female oviduct motoneurons and male sperm duct motoneurons are IMNs that show similar anatomical features and differentiate during metamorphosis, despite appearing in different segments: A7 for oviduct neurons, A9 for sperm duct neurons. These cells are born at the same time and, initially, similar sets are found in A7 and A9 ganglia of larvae of both sexes. The dimorphic adult pattern is generated by sex-specific production and cell death. A7 IMNs differentiate in both sexes through early pupal stages, whereupon they disappear in the male and become the oviduct motoneurons in the female. A9 IMNs are overproduced in the male, and subsequent cell death reduces male cell number and eliminates the small complement of female cells; the surviving male cells develop into the sperm duct motoneurons. Similar IMN arrays are generated in nongenital ganglia, but show non-sex-specific fates. This suggests that both the sex of these cells and their segment of residence play major roles in their subsequent differentiation. 1994 John Wiley & Sons, Inc.     

腰带长体茧蜂毒液器官和卵巢的形态学及其超微结构

应用超薄切片和电镜技术,观察内寄生蜂腰带长体茧蜂Macrocentrus cingulum Brischke毒液器官和卵巢的形态结构。腰带长体茧蜂毒液器官由1个毒囊和2条毒腺组成,毒腺接于毒囊的顶端。毒腺由单层分泌细胞、退化的外胚层细胞和环腔的内膜构成,分泌细胞主要由1个明显的细胞核和1个较大囊状细胞器构成,囊状细胞器的功能是分泌毒液。毒囊由肌肉鞘和扁平细胞层构成,但没有分泌细胞。腰带长体茧蜂卵巢1对,每个卵巢由10条左右卵巢小管组成,与侧输卵管相接处略微膨大形成卵巢萼区。2条侧输卵管在产卵管基部会合形成1条总输卵管与产卵管相接。毒液器官通过毒囊的毒液导管附着在总输卵管上。对寄生蜂毒液器官的生物学、细胞学及在分类进化上的意义进行研究。     

Development of the excretory system in a polyplacophoran mollusc: stages in metanephridial system development

ABSTRACT: BACKGROUND: Two types of excretory systems, protonephridia and metanephridial systems are common among bilaterians. The homology of protonephridia of lophotrochozoan taxa has been widely accepted. In contrast, the homology of metanephridial systems -- including coelomic cavities as functional units -- among taxa as well as the homology between the two excretory systems is a matter of ongoing discussion. This particularly concerns the molluscan kidneys, which are mostly regarded as being derived convergently to the metanephridia of e.g. annelids because of different ontogenetic origin. A reinvestigation of nephrogenesis in polyplacophorans, which carry many primitive traits within molluscs, could shed light on these questions. RESULTS: The metanephridial system of Lepidochitona corrugata develops rapidly in the early juvenile phase. It is formed from a coelomic anlage that soon achieves endothelial organization. The pericardium and heart are formed from the central portion of the anlage. The nephridial components are formed by outgrowth from lateral differentiations of the anlage. Simultaneously with formation of the heart, podocytes appear in the atrial wall of the pericardium. In addition, renopericardial ducts, kidneys and efferent nephroducts, all showing downstream ciliation towards the internal lumen, become differentiated (specimen length: 0.62 mm). Further development consists of elongation of the kidney and reinforcement of filtration and reabsorptive structures. CONCLUSIONS: During development and in fully formed condition the metanephridial system of Lepidochitona corrugata shares many detailed traits (cellular and overall organization) with the protonephridia of the same species. Accordingly, we suggest a serial homology of various cell types and between the two excretory systems and the organs as a whole. The formation of the metanephridial system varies significantly within Mollusca, thus the mode of formation cannot be used as a homology criterion. Because of similarities in overall organization, we conclude that the molluscan metanephridial system is homologous with that of the annelids not only at the cellular but also at the organ level.     

Scanning electron microscopy of the equine oviduct and observations on ciliary currents in vitro at day 2 after ovulation

There are considerable differences between mammalian species in the distribution and activity of ciliated cells within the oviduct, and limited information is available concerning either the distribution or activity of cilia within the equine oviduct. Patterns of ciliary activity were characterized in the ampulla and isthmus of oviducts recovered at 2 d after ovulation from 10 mares, and scanning electron microscopy was used to examine regional differences in the distribution of cilia in oviducts from 3 of these mares. Based upon the motility of 15 microm latex microspheres, ciliary activity was significantly (P < 0.001) greater in the ampullar oviduct compared with that of the isthmic oviduct. The direction of ciliary beat was consistently toward the uterus in all regions of the oviduct. Scanning electron microscopy revealed ciliated and secretory cells in both regions of the oviduct at 2 d after ovulation, with no apparent differences in the proportion of ciliated versus secretory cells.     

Early developing embryos affect the gene expression patterns in the mouse oviduct

Fertilization and development of mouse embryos occur in the ampullae of oviduct. We hypothesize that fetal-maternal communication exists in the preimplantation period, allowing optimal development of embryos. It is known that embryotrophic factors from oviduct affect the development of embryos. Although embryos affect their own transport in the oviduct, the mechanism of action is unknown. As a step toward understanding the action of embryos on oviductal physiology, we adopted suppression subtractive hybridization (SSH) to compare the gene expression in the mouse oviduct containing early embryos with that of oviduct containing oocytes. Ten to twelve 1-cell mouse embryos were transferred to one oviduct of a foster mother and similar number of oocytes were transferred to the contralateral oviduct. The animals were sacrificed after 48 h and their oviducts were excised for mRNA study. Using SSH, we screened out 250 putative positive clones from the subtracted embryo-containing oviduct library and 97 of them were screened positive by reverse dot-blot analysis. DNA sequence analysis identified genes that shared high homology with sequences in GenBank/EMBL database with unknown functions. Overall, 13 of the 90 high-quality sequences (14%) were homologous to 6 different genes previously described. Reverse Northern analysis confirmed that the expression of these genes were higher in the embryo-containing oviduct than in the oocyte-containing oviduct. About 12% of these clones (11/90) were novel. This article is the first to report identification of genes in the oviduct that are upregulated in the presence of embryos during the preimplantation period.     

Seasonal variation of the oviduct of the American alligator,Alligator mississippiensis (Reptilia: Crocodylia)

The annual oviductal cycle of the American alligator, Alligator mississippiensis, is described using light and electron microscopy. Previous work done by Palmer and Guillette ([ 1992 ] Biol Reprod 46:39–47) shed some light on the reproductive morphology of the female alligator oviduct; however, their study was limited and did not report details relating to variation across the reproductive season. We recognize six variable regions of the oviduct: infundibulum, tube, isthmus, anterior uterus, posterior uterus, and vagina. Each area shows variation, to some degree, in the histochemistry and ultrastructure of oviductal secretions. Peak secretory activity occurs during the months of May and June, with the greatest variation occurring in the tube and anterior uterus. During the month of May, high densities of neutral carbohydrates and proteins are found within the tubal and anterior uterine glands. The epithelium of the entire oviduct secretes neutral carbohydrates throughout the year, but many regions lack protein secretions, and the posterior uterine glands show little secretory activity of any type throughout the year. After oviposition, secretory activity decreases drastically, andthe oviduct resembles that of the premating season. This study also provides evidence to support the homology between alligator and bird oviducts. Sperm were observed in glands at the tubal‐isthmus and utero‐vaginal junctions in preovulatory, postovulatory and postovipository females. J. Morphol., 2009. © 2009 Wiley‐Liss, Inc.