BACKGROUND: Body wall anomalies comprise a wide range of malformations. Limb-Body wall complex (LBWC) represents the most severe presentation of this group, with life threatening malformations in practically all the cases, including craniofacial, body wall defects, and limb anomalies. There is no consensus about its etiology and folding and gastrulation defects have been involved. Also, impaired angiogenesis has been proposed as a causative process.
METHODS: We present the case of a masculine stillborn, product of the first pregnancy in a 15-year-old, apparently healthy mother. He was delivered at 31 weeks of gestation due to an early rupture of membranes. He presented with multiple malformations including a wide body wall defect with multiple organ herniation and meromelia of the lower right limb.
CONCLUSIONS: LBWC represents a severe and invariably fatal pathology. There are no described risk factors, nevertheless, this case presented in a teenage mother, a well-described risk factor for other body wall anomalies. Its diagnosis allows us to discriminate between other pathologies that require prenatal or postnatal specialized treatment.

Many crustacean groups show stereotyped cleavage patterns during early ontogeny. However, these patterns differ between the various major crustacean taxa, and a general mode is difficult to extract. Previous studies suggested that also copepods undergo an early cleavage with a more or less stereotyped pattern of blastomere divisions and fates. Yet, copepod embryology has been largely neglected. The last investigation of this kind dates back more than a century and the results are somewhat contradictory when compared with those of other researchers. To overcome these problems, we studied the early development of a so far undescribed calanoid copepod species, Skistodiaptomus sp., applying histochemical staining, confocal laser scanning microscopy, and bifocal 4D microscopy. The blastomere arrangement of the four-cell stage of this species varies to a large degree. It can either form a typical radial pattern with the four blastomeres lying in one plane or a tilted orientation of the axes connecting the sister cells of the previous division. In both cases, a stereotyped division pattern is maintained inside each quadrant during subsequent cleavages. In addition, we found two types of blastomere arrangements with a mirror symmetry. Most divisions within the quadrants follow the perpendicularity rule until the eighth cleavage. Deviations from this rule occur only in the narrow regions where the different quadrants touch and near the site of gastrulation. Gastrulation is initiated around the descendants of one individually identifiable blastomere of the 16-cell stage. This cell divides in a specific manner forming a characteristic cell arrangement, the gastrulation triangle. This gastrulation triangle initiates the internalization process of the gastrulation and it is encircled by another characteristic cell type, the crown cells. Our observations reveal several similarities to the early development of Calanus finmarchicus, another calanoid species. These relate to blastomere arrangements and divisions and the pattern of gastrulation. As Calanoida represent a basal or near basal branch of the copepod tree, this description will provide the ground for reconstruction of the cleavage pattern of the last common ancestor of Copepoda.

Studying the spatial gene expression profiles from in situ hybridization images of the embryo is one of the first steps toward the comprehensive understanding of gene interactions in an organism. In the case of N. vectensis, extracting and collecting these data is a challenging task due to the difficulty of detecting the cell layer through the transparent body plan and changing morphology during the blastula and gastrula stages. Here, first, we introduce a method to algorithmically identify and track the cell layer in N. vectensis embryo from the late blastula to the late gastrula stage. With this, we will be able to extract spatial expression profiles of genes alongside the cell layer and consequently reconstructing the 1D representation of gene expression profiles. Furthermore, we use the morphological configurations of the embryo extracted from confocal images, to model the dynamics of embryos morphology during the gastrulation process in 2D. Ultimately, we provide a visualization tool for studying and comparing the extracted spatial gene expression profiles over the simulated embryo. We anticipate that our method of extraction and visualization to be a starting point for quantifying and collecting more in situ images from various sources, which can potentially accelerate our understanding of gene interactions in the early development of N. vectensis. The method allows researchers to visualize and compare the different gene expressions from different in situ images or different experiments. As an example, we were able to show the complementary expression of NvFoxA-NvSnailA and NvBra-NvErg in the central domain and central/external rings during the development which suggests the possible repression effects between each pair; as it has been discovered by functional analysis.

Understanding genetic interactions during early development of a given organism, is the first step toward unveiling gene regulatory networks (GRNs) that govern a biological process of interest. Predicting such interactions from large expression datasets by performing targeted knock-down/knock-out approaches is a challenging task. We use the currently available expression datasets (in situ hybridization images & qPCR time series) for a basal anthozoan the sea anemone N. vectensis to construct continuous spatiotemporal gene expression patterns during its early development. Moreover, by combining cluster results from each dataset we develop a method that provides testable hypotheses about potential genetic interactions. We show that the analysis of spatial gene expression patterns reveals functional regions of the embryo during the gastrulation. The clustering results from qPCR time series unveils significant temporal events and highlights genes potentially involved in N. vectensis gastrulation. Furthermore, we introduce a method for merging the clustering results from spatial and temporal datasets by which we can group genes that are expressed in the same region and at the time. We demonstrate that the merged clusters can be used to identify GRN interactions involved in various processes and to predict possible activators or repressors of any gene in the dataset. Finally, we validate our methods and results by predicting the repressor effect of NvErg on NvBra in the central domain during the gastrulation that has recently been confirmed by functional analysis.

Split cord malformation (SCM) is classified based on the presence of a bone spur and double dural sac. The authors report on a 6-year-old child with primary enuresis in whom MRI findings were suggestive of Type I SCM, and who had unique intraoperative findings of a horseshoe-shaped split cord terminus anchored by a bone spur without the normally tapering conus and filum. The typical appearance of cauda equina was absent, with all the roots arising from the horseshoe cord terminus. This composite anomaly is probably due to the rare combination of faulty gastrulation with abnormal persistence of endomesenchymal tract causing SCM, with concurrent agenesis of secondary neurulation in turn causing absence of filum.