We have used light-microscopical immunohistochemistry to investigate developmental changes of several neurochemical indicators in retinas of perinatal killifish and goldfish. Immunoreactive proliferating cell nuclear antigen (ir-PCNA/cyclin, a marker for replicating cells) was present in nuclei of all neuroblasts in the early monolayer stage, but was lost progressively in central-to-peripheral and proximal-to-distal order as the layers and cells of the mature retina appeared. The loss of ir-PCNA was slightly prior to the appearance of ir-TH (tyrosine hydroxylase), GAD (glutamic acid decarboxylase) and GS (glutamine synthetase) at the 4th embryonic day (E4) in both fish. Since hatching was earlier in goldfish (E5) than in killifish (E7), neurochemical maturation was evident at 2-3 days before hatching in killifish but not until around hatching in goldfish. Two markers, ir-somatostatin and protein kinase C, were detected by the 1st postnatal day (H1) in goldfish, but not in perinatal or adult killifish retinas. Thus the course of development of killifish and goldfish retinas is similar, but not identical. The validity of ir-PCNA as a marker for proliferating cells is confirmed by the coincidence of its disappearance with the appearance of neurochemical markers for mature, postmitotic retinal cells.
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http://dx.doi.org/10.1016/0165-3806(90)90113-d | DOI Listing |
J Med Genet
December 2024
Neurogenetics Research Center, Fondazione Istituto Neurologico Nazionale C Mondino Istituto di Ricovero e Cura a Carattere Scientifico, Pavia, Lombardia, Italy
Joubert syndrome (JS) is an inherited neurodevelopmental ciliopathy with wide clinical and genetic heterogeneity, whose paradigmatic sign is a peculiar cerebellar and brainstem malformation known as the 'molar tooth sign'. Recessive pathogenic variants in the gene are associated with hydrolethalus syndrome (HLS), a severe disorder characterised by multiple developmental defects leading to intrauterine or perinatal death. However, biallelic variants were also reported in three individuals with JS.
View Article and Find Full Text PDFJ Neurosci
January 2025
Instituto de Neurociencias de Alicante (Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández, CSIC-UMH), Campus San Juan, Alicante 03550, Spain
Eph/ephrin signaling is crucial for organizing retinotopic maps in vertebrates. Unlike other EphAs, which are expressed in the embryonic ventral retina, EphA4 is found in the retinal ganglion cell (RGC) layer at perinatal stages, and its role in mammalian visual system development remains unclear. Using classic in vitro stripe assays, we demonstrate that, while RGC axons are repelled by ephrinB2, they grow on ephrinB1 stripes through EphA4-mediated adhesion.
View Article and Find Full Text PDFCells
October 2024
Department of Pediatrics, Division of Neonatology and Newborn Nursery, University of Wisconsin-Madison, 1300 University Avenue, SMI 112, Madison, WI 53706, USA.
The development of fetal organs can be impacted by systemic changes in maternal circulation, with the placenta playing a pivotal role in maintaining pregnancy homeostasis and nutrient exchange. In clinical obstetrics, oxytocin (OXT) is commonly used to induce labor. To explore the potential role of OXT in the placental homeostasis of OXT, we compared OXT levels in neonatal cord blood among neonates (23-42 weeks gestation) whose mothers either received prenatal OXT or experienced spontaneous labor.
View Article and Find Full Text PDFActa Ophthalmol
February 2025
Department of Ophthalmology, Helsinki University Hospital, University of Helsinki, Helsinki, Finland.
Purpose: To determine the pattern, degree and prevalence of optic disc optical coherence tomography (OCT) alterations in adults born preterm with very low birth weight (VLBW; birth weight < 1500 g).
Methods: Optic disc OCT was assessed in 98 VLBW participants and 139 term-born controls from birth cohorts in Finland and Norway at the mean age of 36 years. The participants had not been treated for retinopathy of prematurity and had no diagnosed brain abnormality.
J Hum Genet
January 2025
Division of Medical Genetics, Kanagawa Children's Medical Center, Yokohama, Japan.
TXNDC15 encodes thioredoxin domain-containing protein 15, a protein disulfide isomerase that plays a role in ciliogenesis. Biallelic TXNDC15 variants have been reported in six individuals of Meckel syndrome (MKS) with perinatal lethal phenotypes, but have not been reported in patients with Joubert syndrome (JS). Here, we describe a 1-year-old female patient with compound heterozygous TXNDC15 variants demonstrating cerebellar vermis hypoplasia with the molar tooth sign, mild holoprosencephaly, and cortical abnormalities.
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