Stable isotope compositions of mammoth teeth from Niederweningen, Switzerland: Implications for the Late Pleistocene climate, environment, and diet

Oxygen and carbon isotope compositions of well-preserved mammoth teeth from the Middle Wurmian (40-70 ka) peat layer of Niederweningen, the most important mammoth site in Switzerland, were analysed to reconstruct Late Pleistocene palaeoclimatic and palaeoenvironmental conditions. Drinking water (delta(18)O values of approximately -12.3 +/- 0.9 parts per thousand were calculated front oxygen isotope compositions of mammoth tooth enamel apatite using a species-specific calibration for modern elephants. These delta(18)O(H2O) values reflect the mean oxygen isotope composition of the palaeo-precipitation and are similar to those directly measured for fate Pleistocene groundwater from aquifers in northern Switzerland and southern Germany. Using a present-day delta(18)O(H2)o-precipitation-air temperature relation for Switzerland, a mean annual air temperature (MAT) of around 4.3 +/- 2.1 degrees C can be calculated for the Middle Wurmian at this site. This MAT is in good agreement with palaeotemperature estimates on the basis of Middle Wurmian groundwater recharge temperatures and beetle assemblages. Hence, the climatic conditions in this region were around 4 degrees C cooler during the Middle Wurmian interstadial phase, around 45-50ka BP, than they are today. During this period the mammoths from Niederweningen lived in an open tundra-like, C(3) plant-dominated environment as indicated by enamel (delta(13)C values of -11.5 +/- 0.3 parts per thousand and pollen and macroplant fossils found in the embedding peat. The low variability of enamel delta(13)C and delta(18)O values from different mammoth teeth reflects similar environmental conditions and supports a relatively small time frame for the fossil assemblage. (C) 2006 Elsevier Ltd and INQUA. All rights reserved.

Paleobiology and skeletochronology of Jurassic dinosaurs: implications from the histology and oxygen isotope compositions of bones

Fossil biogenic phosphate of fast-growing primary bone tissue of dinosaurs can preserve a histologic and isotopic time-series of annual seasonality in temperature variations, similar to tooth enamel and other accretionary skeletal phases such as corals or wood. On two bone fragments from sympatric dinosaurs with different histologic patterns of bone growth, high-resolution oxygen isotope profiles were analyzed along the radial direction of bone growth. The investigated specimens are from the Jurassic Shishugou Formation in the Junggar Basin, NW China and have distinct patterns of compositional variation. A fibrolamellar dinosaur bone with multiple lines of arrested growth (LAGs) and periodic growth cycles of decreasing bone laminae thickness displays a cyclic intra-bone variation in delta(18)O values of about 2parts per thousand corresponding with the LAGs. These growth cycles in fast-growing fibrolamellar bone provide evidence for seasonal growth of dinosaurs in lower latitudes ( similar to 45degreesN), possibly influenced by a monsoon-type paleoclimate. Seasonal changes in temperature and water supply are consistent with the oxygen isotope composition measured in dinosaur bone phosphate as well as with growth rings in contemporaneous fossil conifer wood from the same locality. In contrast, a plexiform sympatric sauropod bone displays continuous growth, free of LAGs and has a lower intra-bone variation of less than or equal to 0.8parts per thousand. Differences in bone histology are also reflected in the oxygen isotopic composition and its intra-bone variability, indicating different physiological responses to external climatic stress between sympatric dinosaur species. Seasonal intra-bone oxygen isotope variations combined with bone histology may thus yield new insights into species-specific response to climatic stress and its influence on dinosaur growth, formation of growth marks, growth rates, as welt as dinosaur thermophysiology. (C) 2004 Elsevier B.V All rights reserved.

Achondrogenesis Type 1B.

DISEASE CHARACTERISTICS: Clinical features of achondrogenesis type 1B (ACG1B) include extremely short limbs with short fingers and toes, hypoplasia of the thorax, protuberant abdomen, and hydropic fetal appearance caused by the abundance of soft tissue relative to the short skeleton. The face is flat, the neck is short, and the soft tissue of the neck may be thickened. Death occurs prenatally or shortly after birth. DIAGNOSIS/TESTING: The diagnosis of ACG1B rests on a combination of clinical, radiologic, and histopathologic features. SLC26A2 (DTDST) is the only gene known to be associated with ACG1B. Molecular genetic testing is available on a clinical basis. MANAGEMENT: Treatment of manifestations: palliative care for liveborn neonates. GENETIC COUNSELING: ACG1B is inherited in an autosomal recessive manner. At conception, each sib of a proband with ACG1B has a 25% chance of being affected, a 50% chance of being an asymptomatic carrier, and a 25% chance of being unaffected and not a carrier. Once an at-risk sib is known to be unaffected, the risk of his/her being a carrier is 2/3. Carrier testing for at-risk relatives and prenatal testing for pregnancies at increased risk are possible if both disease-causing alleles in the family are known and the carrier status of the parents has been confirmed. Ultrasound examination after 14-15 weeks' gestation can be diagnostic.

PAX6 mutations in Egyptian families with aniridia

Methods Ten patients with aniridia from 3 families of Egyptian origin underwent full ophthalmologic, general and neurological examination, and blood drawing. Cerebral MRI was performed in the index case of each family. Genomic DNA was prepared from venous leukocytes and direct sequencing of all the exons and intron-exon junctions of the PAX6 gene was performed after PCR amplification. Results Common features observed in the three families included absence of iris tissue, corneal pannus with different degrees of severity and foveal hypoplasia with severely reduced visual acuity. In families 2 and 3, additional findings such as lens dislocation, lens opacities or polar cataract and glaucoma were observed. We identified two novel (c.170-174delTGGGC [p.L57fs17] and c.475delC [p.R159fs47]) and one known (c.718C>T) PAX6 mutations in the affected members of the 3 families. Systemic and neurological examination was normal in all ten affected patients. Cerebral MRI showed absence of the pineal gland in all three index patients. Severe hypoplasia of the brain anterior commissure was associated to the p.L57fs17mutation, absence of the posterior commissure to both p.R159fs47 and p.R240X, and optic chiasma atrophy and almost complete agenesis of the corpus callosum to p.R240X. Conclusions We identified two novel PAX6 mutations in families with severe aniridia from Northern Egypt, an ethnic group which is not well studied. In addition to common phenotype of aniridia and despite normal neurological examination, absence of the pineal gland was observed in all 3 index patients. The heterogeneity of brain anomalies related to PAX6 mutations is underexplored and is highlighted in this study.

Congenital diaphragmatic hernia: current status and review of the literature.

Treatment of congenital diaphragmatic hernia (CDH) challenges obstetricians, pediatric surgeons, and neonatologists. Persistent pulmonary hypertension (PPHT) associated with lung hypoplasia in CDH leads to a high mortality rate at birth. PPHT is principally due to an increased muscularization of the arterioles. Management of CDH has been greatly improved by the introduction of prenatal surgical intervention with tracheal obstruction (TO) and by more appropriate postnatal care. TO appears to accelerate fetal lung growth and to increase the number of capillary vessels and alveoli. Improvement of postnatal care over the last years is mainly due to the avoidance of lung injury by applying low peak inflation pressure during ventilation. The benefits of other drugs or technical improvements such as the use of inhaled nitric oxide or extracorporeal membrane oxygenation (ECMO) are still being debated and no single strategy is accepted worldwide. Despite intensive clinical and experimental research, the treatment of newborn with CDH remains difficult.

Holt Oram syndrome: a registry-based study in Europe.

BACKGROUND: Holt-Oram syndrome (HOS) is an autosomal dominant disorder characterised by upper limb anomalies and congenital heart defects. We present epidemiological and clinical aspects of HOS patients using data from EUROCAT (European Surveillance of Congenital Anomalies) registries. METHODS: The study was based on data collected during 1990-2011 by 34 registries. The registries are population-based and use multiple sources of information to collect data on all types of birth using standardized definitions, methodology and coding. Diagnostic criteria for inclusion in the study were the presence of radial ray abnormalities and congenital heart disease (CHD), or the presence of either radial ray anomaly or CHD, with family history of HOS. RESULTS: A total of 73 cases of HOS were identified, including 11 (15.1%) TOPFA and 62 (84.9%) LB. Out of 73 HOS cases, 30.8% (20/65) were suspected prenatally, 55.4% (36/65) at birth, 10.7% (7/65) in the first week of life, and 3.1% (2/65) in the first year of life. The prenatal detection rate was 39.2% (20/51), with no significant change over the study period. In 55% (11/20) of prenatally detected cases, parents decided to terminate pregnancy. Thumb anomalies were reported in all cases. Agenesis/hypoplasia of radius was present in 49.2% (30/61), ulnar aplasia/hypoplasia in 24.6% (15/61) and humerus hypoplasia/phocomelia in 42.6% (26/61) of patients. Congenital heart defects (CHD) were recorded in 78.7% (48/61) of patients. Isolated septal defects were present in 54.2 (26/48), while 25% (12/48) of patients had complex/severe CHD. The mean prevalence of HOS diagnosed prenatally or in the early years of life in European registries was 0.7 per 100,000 births or 1:135,615 births. CONCLUSIONS: HOS is a rare genetic condition showing regional variation in its prevalence. It is often missed prenatally, in spite of the existence of major structural anomalies. When discovered, parents in 45% (9/20) of cases opt for the continuation of pregnancy. Although a quarter of patients have severe CHD, the overall first week survival is very good, which is important information for counselling purposes.

Verteilung des roten Zahnschmelzes im Gebiss der Soricidae (Mammalia, Insectivora)

The distribution of red, iron-containing enamel in the teeth of shrews (Soricidae) was investigated by optical and scanning electron microscopy in order to determine its function. Transverse and longitudinal sections of crania with mandibles in occlusion demonstrate that the red enamel in molars is restricted to corresponding wear facets (lingual side of upper molars, buccal side of lower molars). The projecting, scissor-like cutting edges produced by wear are composed of iron-containing enamel which wears away more slowly than adjacent white enamel. Therefore, this red enamel must be more resistant to abrasion and serves to prolong the usefullness of cutting edges. Finally, two alternative hypotheses are proposed to explain the secondary loss of the red, iron-bearing enamel in members of the Soricidae which lack this material.

MMP13 mutations are the cause of recessive metaphyseal dysplasia, Spahr type.

Metaphyseal dysplasia, Spahr type (MDST; OMIM 250400) was described in 1961 based on the observation of four children in one family who had rickets-like metaphyseal changes but normal blood chemistry and moderate short stature. Its molecular basis and nosologic status remained unknown. We followed up on those individuals and diagnosed the disorder in an additional member of the family. We used exome sequencing to ascertain the underlying mutation and explored its consequences on three-dimensional models of the affected protein. The MDST phenotype is associated with moderate short stature and knee pain in adults, while extra-skeletal complications are not observed. The sequencing showed that MDST segregated with a c.619T>G single nucleotide transversion in MMP13. The predicted non-conservative amino acid substitution, p.Trp207Gly, disrupts a crucial hydrogen bond in the calcium-binding region of the catalytic domain of the matrix metalloproteinase, MMP13. The MDST phenotype is associated with recessive MMP13 mutations, confirming the importance of this metalloproteinase in the metaphyseal growth plate. Dominant MMP13 mutations have been associated with metaphyseal anadysplasia (OMIM 602111), while a single child homozygous for a MMP13 mutation had been previously diagnosed as "recessive metaphyseal anadysplasia," that we conclude is the same nosologic entity as MDST. Molecular confirmation of MDST allows distinction of it from dominant conditions (e.g., metaphyseal dysplasia, Schmid type; OMIM # 156500) and from more severe multi-system conditions (such as cartilage-hair hypoplasia; OMIM # 250250) and to give precise recurrence risks and prognosis. © 2014 Wiley Periodicals, Inc.

BRF1 mutations alter RNA polymerase III-dependent transcription and cause neurodevelopmental anomalies.

RNA polymerase III (Pol III) synthesizes tRNAs and other small noncoding RNAs to regulate protein synthesis. Dysregulation of Pol III transcription has been linked to cancer, and germline mutations in genes encoding Pol III subunits or tRNA processing factors cause neurogenetic disorders in humans, such as hypomyelinating leukodystrophies and pontocerebellar hypoplasia. Here we describe an autosomal recessive disorder characterized by cerebellar hypoplasia and intellectual disability, as well as facial dysmorphic features, short stature, microcephaly, and dental anomalies. Whole-exome sequencing revealed biallelic missense alterations of BRF1 in three families. In support of the pathogenic potential of the discovered alleles, suppression or CRISPR-mediated deletion of brf1 in zebrafish embryos recapitulated key neurodevelopmental phenotypes; in vivo complementation showed all four candidate mutations to be pathogenic in an apparent isoform-specific context. BRF1 associates with BDP1 and TBP to form the transcription factor IIIB (TFIIIB), which recruits Pol III to target genes. We show that disease-causing mutations reduce Brf1 occupancy at tRNA target genes in Saccharomyces cerevisiae and impair cell growth. Moreover, BRF1 mutations reduce Pol III-related transcription activity in vitro. Taken together, our data show that BRF1 mutations that reduce protein activity cause neurodevelopmental anomalies, suggesting that BRF1-mediated Pol III transcription is required for normal cerebellar and cognitive development.

Nd and Sr isotope compositions in modern and fossil bones - Proxies for vertebrate provenance and taphonomy

Rare earth elements (REE), while not essential for the physiologic functions of animals, are ingested and incorporated in ppb concentrations in bones and teeth. Nd isotope compositions of modern bones of animals from isotopically distinct habitats demonstrate that the (143)Nd/(144)Nd of the apatite can be used as a fingerprint for bedrock geology or ambient water mass. This potentially allows the provenance and migration of extant vertebrates to be traced, similar to the use of Sr isotopes. Although REE may be enriched by up to 5 orders of magnitude during diagenesis and recrystallization of bone apatite, in vivo (143)Nd/(144)Nd may be preserved in the inner cortex of fossil bones or enamel. However, tracking the provenance of ancient or extinct vertebrates is possible only for well-preserved archeological and paleontological skeletal remains with in vivo-like Nd contents at the ppb-level. Intra-bone and -tooth REE analysis can be used to screen for appropriate areas. Large intra-bone Nd concentration gradients of 10(1)-10(3) are often measured. Nd concentrations in the inner bone cortex increase over timescales of millions of years, while bone rims may be enriched over millenial timescales. Nevertheless, epsilon(Nd) values are often similar within one epsilon(Nd) unit within a single bone. Larger intra-bone differences in specimens may either reflect a partial preservation of in vivo values or changing epsilon(Nd) values of the diagenetic fluid during fossilization. However, most fossil specimens and the outer rims of bones will record taphonomic (143)Nd/(144)Nd incorporated post mortem during diagenesis. Unlike REE patterns, (143)Nd/(144)Nd are not biased by fractionation processes during REE-uptake into the apatite crystal lattice, hence the epsilon(Nd) value is an important tracer for taphonomy and reworking. Bones and teeth from autochthonous fossil assemblages have small variations of +/- 1 epsilon(Nd) unit only. In contrast, fossil bones and teeth from over 20 different marine and terrestrial fossil sites have a total range of epsilon(Nd) values from -13.0 to 4.9 (n = 80), often matching the composition of the embedding sediment. This implies that the surrounding sediment is the source of Nd in the fossil bones and that the specimens of this study seem not to have been reworked. Differences in epsilon(Nd) values between skeletal remains and embedding sediment may either indicate reworking of fossils and/or a REE-uptake from a diagenetic fluid with non-sediment derived epsilon(Nd) values. The latter often applies to fossil shark teeth, which may preserve paleo-seawater values. Complementary to epsilon(Nd) values, (87)Sr/(86)Sr can help to further constrain the fossil provenance and reworking. (C) 2011 Elsevier Ltd. All rights reserved.

Evolutionary comparison provides evidence for pathogenicity of RMRP mutations.

Cartilage-hair hypoplasia (CHH) is a pleiotropic disease caused by recessive mutations in the RMRP gene that result in a wide spectrum of manifestations including short stature, sparse hair, metaphyseal dysplasia, anemia, immune deficiency, and increased incidence of cancer. Molecular diagnosis of CHH has implications for management, prognosis, follow-up, and genetic counseling of affected patients and their families. We report 20 novel mutations in 36 patients with CHH and describe the associated phenotypic spectrum. Given the high mutational heterogeneity (62 mutations reported to date), the high frequency of variations in the region (eight single nucleotide polymorphisms in and around RMRP), and the fact that RMRP is not translated into protein, prediction of mutation pathogenicity is difficult. We addressed this issue by a comparative genomic approach and aligned the genomic sequences of RMRP gene in the entire class of mammals. We found that putative pathogenic mutations are located in highly conserved nucleotides, whereas polymorphisms are located in non-conserved positions. We conclude that the abundance of variations in this small gene is remarkable and at odds with its high conservation through species; it is unclear whether these variations are caused by a high local mutation rate, a failure of repair mechanisms, or a relaxed selective pressure. The marked diversity of mutations in RMRP and the low homozygosity rate in our patient population indicate that CHH is more common than previously estimated, but may go unrecognized because of its variable clinical presentation. Thus, RMRP molecular testing may be indicated in individuals with isolated metaphyseal dysplasia, anemia, or immune dysregulation.

Early diagenesis of bone and tooth apatite in fluvial and marine settings: Constraints from combined oxygen isotope, nitrogen and REE analysis

Fossil bones and teeth of Late Pleistocene terrestrial mammals from Rhine River gravels (RS) and the North Sea (NS), that have been exposed to chemically and isotopically distinct diagenetic fluids (fresh water versus seawater), were investigated to study the effects of early diagenesis on biogenic apatite. Changes in phosphate oxygen isotopic composition (delta O-18(PO4)), nitrogen content (wt.% N) and rare earth element (REE) concentrations were measured along profiles within bones that have not been completely fossilized, and in skeletal tissues (bone, dentine, enamel) with different susceptibilities to diagenetic alteration. Early diagenetic changes of elemental and isotopic compositions of apatite in fossil bone are related to the loss of the stabilizing collagen matrix. The REE concentration is negatively correlated with the nitrogen content, and therefore the amount of collagen provides a sensitive proxy for early diagenetic alteration. REE patterns of RS and NS bones indicate initial fossilization in a fresh water fluid with similar REE compositions. Bones from both settings have nearly collagen-free, REE-, U-, F- and Sr-enriched altered outer rims, while the collagen-bearing bone compacta in the central part often display early diagenetic pyrite void-fillings. However, NS bones exposed to Holocene seawater have outer rim delta O-18(PO4) values that are 1.1 to 2.6 parts per thousand higher compared to the central part of the same bones (delta O-18(PO4) = 18.2 +/- 0.9 parts per thousand, n = 19). Surprisingly, even the collagen-rich bone compacta with low REE contents and apatite crystallinity seems altered, as NS tooth enamel (delta O-18(PO4) =15.0 +/- 0.3 parts per thousand, n=4) has about 3%. lower delta O-18(PO4) values, values that are also similar to those of enamel from RS teeth. Therefore, REE concentration, N content and apatite crystallinity are in this case only poor proxies for the alteration of delta O-18(PO4) values. Seawater exposure of a few years up to 8 kyr can change the delta O-18(PO4) values of the bone apatite by > 3 parts per thousand. Therefore, bones fossilized in marine settings must be treated with caution for palaeoclimatic reconstructions. However, enamel seems to preserve pristine delta O-18(PO4) values on this time scale. Using species-specific calibrations for modern mammals, a mean delta O-18(H2O) value can be reconstructed for Late Pleistocene mammalian drinking water of around -9.2 +/- 0.5 parts per thousand, which is similar to that of Late Pleistocene groundwater from central Europe. (c) 2008 Elsevier B.V. All rights reserved.

Axial spondylometaphyseal dysplasia: Additional reports.

Axial spondylometaphyseal dysplasia (SMD) (OMIM 602271) is an uncommon skeletal dysplasia characterized by metaphyseal changes of truncal-juxtatruncal bones, including the proximal femora, and retinal abnormalities. The disorder has not attracted much attention since initially reported; however, it has been included in the nosology of genetic skeletal disorders [Warman et al. (2011); Am J Med Genet Part A 155A:943-968] in part because of a recent publication of two additional cases [Isidor et al. (2010); Am J Med Genet Part A 152A:1550-1554]. We report here on the clinical and radiological manifestations in seven affected individuals from five families (three sporadic cases and two familial cases). Based on our observations and Isidor's report, the clinical and radiological hallmarks of axial SMD can be defined: The main clinical findings are postnatal growth failure, rhizomelic short stature in early childhood evolving into short trunk in late childhood, and thoracic hypoplasia that may cause mild to moderate respiratory problems in the neonatal period and later susceptibility to airway infection. Impaired visual acuity comes to medical attention in early life and function rapidly deteriorates. Retinal changes are diagnosed as retinitis pigmentosa or pigmentary retinal degeneration on fundoscopic examination and cone-rod dystrophy on electroretinogram. The radiological hallmarks include short ribs with flared, cupped anterior ends, mild spondylar dysplasia, lacy iliac crests, and metaphyseal irregularities essentially confined to the proximal femora. Equally affected sibling pairs of opposite gender and parental consanguinity are strongly suggestive of autosomal recessive inheritance. © 2011 Wiley-Liss, Inc.

Ubiquitin Ligases of the N-End Rule Pathway: Assessment of Mutations in UBR1 That Cause the Johanson-Blizzard Syndrome.

Background: Johanson-Blizzard syndrome (JBS; OMIM 243800) is an autosomal recessive disorder that includes congenital exocrine pancreatic insufficiency, facial dysmorphism with the characteristic nasal wing hypoplasia, multiple malformations, and frequent mental retardation. Our previous work has shown that JBS is caused by mutations in human UBR1, which encodes one of the E3 ubiquitin ligases of the N-end rule pathway. The N-end rule relates the regulation of the in vivo half-life of a protein to the identity of its N-terminal residue. One class of degradation signals (degrons) recognized by UBR1 are destabilizing N-terminal residues of protein substrates.Methodology/Principal Findings: Most JBS-causing alterations of UBR1 are nonsense, frameshift or splice-site mutations that abolish UBR1 activity. We report here missense mutations of human UBR1 in patients with milder variants of JBS. These single-residue changes, including a previously reported missense mutation, involve positions in the RING-H2 and UBR domains of UBR1 that are conserved among eukaryotes. Taking advantage of this conservation, we constructed alleles of the yeast Saccharomyces cerevisiae UBR1 that were counterparts of missense JBS-UBR1 alleles. Among these yeast Ubr1 mutants, one of them (H160R) was inactive in yeast-based activity assays, the other one (Q1224E) had a detectable but weak activity, and the third one (V146L) exhibited a decreased but significant activity, in agreement with manifestations of JBS in the corresponding JBS patients.Conclusions/Significance: These results, made possible by modeling defects of a human ubiquitin ligase in its yeast counterpart, verified and confirmed the relevance of specific missense UBR1 alleles to JBS, and suggested that a residual activity of a missense allele is causally associated with milder variants of JBS.

Mutations in tubulin genes are frequent causes of various foetal malformations of cortical development including microlissencephaly.

Complex cortical malformations associated with mutations in tubulin genes are commonly referred to as "Tubulinopathies". To further characterize the mutation frequency and phenotypes associated with tubulin mutations, we studied a cohort of 60 foetal cases. Twenty-six tubulin mutations were identified, of which TUBA1A mutations were the most prevalent (19 cases), followed by TUBB2B (6 cases) and TUBB3 (one case). Three subtypes clearly emerged. The most frequent (n = 13) was microlissencephaly with corpus callosum agenesis, severely hypoplastic brainstem and cerebellum. The cortical plate was either absent (6/13), with a 2-3 layered pattern (5/13) or less frequently thickened (2/13), often associated with neuroglial overmigration (4/13). All cases had voluminous germinal zones and ganglionic eminences. The second subtype was lissencephaly (n = 7), either classical (4/7) or associated with cerebellar hypoplasia (3/7) with corpus callosum agenesis (6/7). All foetuses with lissencephaly and cerebellar hypoplasia carried distinct TUBA1A mutations, while those with classical lissencephaly harbored recurrent mutations in TUBA1A (3 cases) or TUBB2B (1 case). The third group was polymicrogyria-like cortical dysplasia (n = 6), consisting of asymmetric multifocal or generalized polymicrogyria with inconstant corpus callosum agenesis (4/6) and hypoplastic brainstem and cerebellum (3/6). Polymicrogyria was either unlayered or 4-layered with neuronal heterotopias (5/6) and occasional focal neuroglial overmigration (2/6). Three had TUBA1A mutations and 3 TUBB2B mutations. Foetal TUBA1A tubulinopathies most often consist in microlissencephaly or classical lissencephaly with corpus callosum agenesis, but polymicrogyria may also occur. Conversely, TUBB2B mutations are responsible for either polymicrogyria (4/6) or microlissencephaly (2/6).