Morphogenesis of the different types of photoreceptors of the chicken (Gallus domesticus) retina and the effect of amblyopia in neonatal chicken.

Despite the great variety in chicken photoreceptors, existing morphogenetic studies only deal with two types: rods and cones. We have therefore examined by scanning electron microscopy the first appearance and maturation of different retinal photoreceptors in 36 chicken embryos (Gallus domesticus), aged 5-19 days prehatching. On day 5 of incubation, chicken retinae were only composed of proliferating ventricular cells devoid of photoreceptors. On day 8, outer mitotic cells were separated from inner differentiating photoreceptors, by the transient layer of Chievitz. Ball-like protrusions appeared at the ventricular surface, representing the first signs of photoreceptor inner segment formation. From day 10 onward, double cones, single cones, and rods could be clearly distinguished, and occasional cilia were detected at their tip. On day 12, inner segments had increased in length and diameter, and frequently carried a cilium representing the beginning of outer segment formation. On day 14, most photoreceptors displayed a distinct outer segment. On day 19, photoreceptors had essentially assumed adult morphology. Based on the shape of their outer segments, two subtypes of cones and three subtypes of double cones could be distinguished. Throughout development, we observed microvilli close to maturing photoreceptors, either originating from their lateral sides, from their tip, or from Müller cells. Microvillus density peaked between day 12 and 14, indicating an important role in photoreceptor morphogenesis. Unilateral occlusion of the eyes of posthatching chicken reduced the proportion of double cones to single cones in the retina, indicating dependence of retinal morphogenesis upon functional activity of visual cells.

Ultrastructural characterization of whole hydrosalpinx from infertile Chinese women.

Hydrosalpinx (HSP) has been shown to be detrimental to the outcome of assisted reproduction, but little is known of its pathology. This prospective study examined and detailed ultrastructural characterization of HSP of infertile women presenting for assisted reproductive treatments. Both light and electron microscopies were used to characterize HSP. Hematoxylin and eosin staining of HSP showed areas without epithelial cell lining or with abnormalities such as flattening of the epithelial layer and exfoliation of epithelial cells with occasional normal columnar epithelial lining. HSP muscle fibers were atrophic and occasionally replaced by fibrous tissues, or separated by areas of severe edema. Inflammatory cells could be found in hydrosalpinx fluid (HF) in the lumen in areas with flattened to no epithelial cells, without epithelial lining, as well as in dilated blood vessels and/or lymph vessels. Scanning electron microscopy of the epithelial surface revealed epithelial denudation-severe loss of both cilia and microvilli and stomata exuding globular bodies on eroded ampulla surfaces. Severe chronic inflammation and damage to the epithelial lining and musculature of Fallopian tubes and the presence of inflammatory cells provides an explanation for HF formation, and thus for the detrimental effects of HF on reproductive processes and IVF outcome.

Characterization of epithelial cell culture from human hydrosalpinges and effects of its conditioned medium on embryo development and sperm motility.

BACKGROUND: Recent studies have reported the negative impact of hydrosalpinx on IVF outcome. Toxic effects of hydrosalpinx fluid (HF) have been the main reason for the recommendation of functional surgery, salpingectomy, prior to IVF. The present study characterized hydrosalpinx epithelial cell culture and examined the effects of its conditioned medium (CM) on sperm motility, acrosome reaction and embryo development. METHODS: Normal Fallopian tubes (n = 6) and hydrosalpinges (n = 9) were used to prepare epithelial cell culture and CM. Epithelial cell characterization was confirmed using electron microscopy. Sperm motility and acrosome reaction were determined using computer-aided sperm analysis and acrobead assay respectively and embryo development by mouse embryo development assay. RESULTS: The percentage of human motile sperm incubated in hydrosalpinx CM was significantly different from those in normal Fallopian tube (NFT) CM and modified human tubal fluid medium (hTF) (control) (P < 0.05 at 3 h and P < 0.001 at 5 and 24 h), with alteration in movement characteristic, linearity, 24 h after incubation in hydrosalpinx CM (P < 0.05). However, other sperm movement characteristics remained unchanged. Reduced acrosome reaction and poor mouse embryo development were also observed in hydrosalpinx CM but not in NFT CM and hTF. CONCLUSIONS: The results suggest that hydrosalpinx epithelial cells may be producing a fluid milieu hostile to sperm and early embryo development. The established epithelial cell culture system may provide a model to further investigate the mechanisms underlying the toxic effects of HF on embryo development and the adverse effects on IVF outcomes.

Novel identification of the different types of cones in the retina of the chicken.

1. Although single cones and double cones in the chicken retina had been documented for more than 30 years, the exact morphology of these cells had never been studied by the scanning electronmicroscopy. In this brief report, we present the evidence for the first time the existence of two types of single cones and three types of double cones (termed as types A, B. and C), each with distinct morphology. 2. The proportion of type A:type B:type C double cones, as estimated from the midperipheral and central regions of our scanning specimens, was about 30%:50%:20%. 3. Based on the literature data that red oil droplets reside in single cones and yellow oil droplets in chief cones of the double cones, the proportion of single to double cones was deciphered and the relative proportion was estimated to be 1:0.91 in the central region, 1:0.92 in the midperiphery, and 1:0.84 in the periphery.