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Background: In live-born children with Down syndrome it may be very difficult for the clinician or midwife assisting at the delivery to recognise Down syndrome in newborn babies due to varying physical appearances. Meanwhile more and more therapeutical interventions become available that should start early in life. We were interested in the age at the postnatal diagnosis of Down syndrome, and found no literature on the subject. Methods: We studied the age at the diagnosis of Down syndrome for live-born babies born in the period of 1981-2000 and registered by the European Registration of Congenital Anomalies in the northern part of The Netherlands. Results: For 289 children, data on the age at the postnatal diagnosis were available, in 70.8% of whom there was suspicion of DS on the day of birth. In 1.7% of the cases, the diagnosis was made after 1 year. Place of birth and the specialty of the health worker assisting at the delivery were associated with age at diagnosis. When the child was delivered at hospital, 96.4% of the Down syndrome cases had been diagnosed within 1 month compared to 81.3% following home delivery. Conclusion: In some cases of Down syndrome in live-born babies, the diagnosis is made only after months or a year. The diagnosis was made faster in babies born in hospital compared to those born at home. [ABSTRACT FROM AUTHOR]

Practical biodiversity conservation relies on delineation of biologically meaningful units. Manta and devil rays (Mobulidae) are threatened worldwide, yet morphological similarities and a succession of recent taxonomic changes impede the development of an effective conservation strategy. Here, we generate genome-wide single nucleotide polymorphism (SNP) data from a geographically and taxonomically representative set of manta and devil ray samples to reconstruct phylogenetic relationships and evaluate species boundaries under the general lineage concept. We show that nominal species units supported by alternative data sources constitute independently evolving lineages, and find robust evidence for a putative new species of manta ray in the Gulf of Mexico. Additionally, we uncover substantial incomplete lineage sorting indicating that rapid speciation together with standing variation in ancestral populations has driven phylogenetic uncertainty within Mobulidae. Finally, we detect cryptic diversity in geographically distinct populations, demonstrating that management below the species level may be warranted in certain species. Overall, our study provides a framework for molecular genetic species delimitation that is relevant to wide-ranging taxa of conservation concern, and highlights the potential for genomic data to support effective management, conservation and law enforcement strategies., (© 2020 The Authors. Molecular Ecology published by John Wiley & Sons Ltd.)

Manta and devil rays are an iconic group of globally distributed pelagic filter feeders, yet their evolutionary history remains enigmatic. We employed next generation sequencing of mitogenomes for nine of the 11 recognized species and two outgroups; as well as additional Sanger sequencing of two mitochondrial and two nuclear genes in an extended taxon sampling set. Analysis of the mitogenome coding regions in a Maximum Likelihood and Bayesian framework provided a well-resolved phylogeny. The deepest divergences distinguished three clades with high support, one containing Manta birostris, Manta alfredi, Mobula tarapacana, Mobula japanica and Mobula mobular; one containing Mobula kuhlii, Mobula eregoodootenkee and Mobula thurstoni; and one containing Mobula munkiana, Mobula hypostoma and Mobula rochebrunei. Mobula remains paraphyletic with the inclusion of Manta, a result that is in agreement with previous studies based on molecular and morphological data. A fossil-calibrated Bayesian random local clock analysis suggests that mobulids diverged from Rhinoptera around 30 Mya. Subsequent divergences are characterized by long internodes followed by short bursts of speciation extending from an initial episode of divergence in the Early and Middle Miocene (19-17 Mya) to a second episode during the Pliocene and Pleistocene (3.6 Mya - recent). Estimates of divergence dates overlap significantly with periods of global warming, during which upwelling intensity - and related high primary productivity in upwelling regions - decreased markedly. These periods are hypothesized to have led to fragmentation and isolation of feeding regions leading to possible regional extinctions, as well as the promotion of allopatric speciation. The closely shared evolutionary history of mobulids in combination with ongoing threats from fisheries and climate change effects on upwelling and food supply, reinforces the case for greater protection of this charismatic family of pelagic filter feeders., (Copyright © 2014 Elsevier Inc. All rights reserved.)

In the past decade, the study of dispersal of marine organisms has shifted from focusing predominantly on the larval stage to a recent interest in adult movement. Antitropical distributions provide a unique system to assess vagility and dispersal. In this study, we have focused on an antitropical wrasse genus, Semicossyphus, which includes the California sheephead, S. pulcher, and Darwin's sheephead, S. darwini. Using a phylogenetic approach based on mitochondrial and nuclear markers, and a population genetic approach based on mitochondrial control region sequences and 10 microsatellite loci, we compared the phylogenetic relationships of these two species, as well as the population genetic characteristics within S. pulcher. While S. pulcher and S. darwini are found in the temperate eastern Pacific regions of the northern and southern hemispheres, respectively, their genetic divergence was very small (estimated to have occurred between 200 and 600 kya). Within S. pulcher, genetic structuring was generally weak, especially along mainland California, but showed weak differentiation between Sea of Cortez and California, and between mainland California and Channel Islands. We highlight the congruence of weak genetic differentiation both within and between species and discuss possible causes for maintenance of high gene flow. In particular, we argue that deep and cooler water refugia are used as stepping stones to connect distant populations, resulting in low levels of genetic differentiation.

The complete mitochondrial genome of a widely distributed pelagic ray, the Spinetail Devilray (Mobula japanica), consists of 18,880 bp with high A+T and low G content. Gene configuration and length is similar to other vertebrates and comprises 13 protein-coding genes, 2 rRNAs genes (12S and 16S rRNA), 22 tRNAs genes, and 1 major non-coding sequence, the control region. A remarkable feature in the mitochondrial genome of M. japanica is three tandemly repeated areas in the control region, together comprising a length of almost 1500 bp, making this to our knowledge the longest elasmobranch mitochondrial genome published so far.

Eleven microsatellites were characterized for Semicossyphus pulcher (California sheephead) using an enrichment protocol. The number of alleles varied from three to 14 for a sample of 40 individuals from two populations. Expected heterozygosities ranged from 0.311 to 0.891. All loci but one were in Hardy-Weinberg equilibrium. No evidence for linkage disequilibrium was observed. These polymorphic microsatellites will be useful for genetic diversity and connectivity analyses of S. pulcher., (© 2009 The Authors. Journal compilation © 2009 Blackwell Publishing Ltd.)