ATP5PO levels regulate enteric nervous system development in zebrafish, linking Hirschsprung disease to Down Syndrome.

Hirschsprung disease (HSCR) is a complex genetic disorder characterized by the absence of enteric nervous system (ENS) in the distal region of the intestine. Down Syndrome (DS) patients have a >50-fold higher risk of developing HSCR than the general population, suggesting that overexpression of human chromosome 21 (Hsa21) genes contribute to HSCR etiology. However, identification of responsible genes remains challenging. Here, we describe a genetic screening of potential candidate genes located on Hsa21, using the zebrafish. Candidate genes were located in the DS-HSCR susceptibility region, expressed in the human intestine, were known potential biomarkers for DS prenatal diagnosis, and were present in the zebrafish genome. With this approach, four genes were selected: RCAN1, ITSN1, ATP5PO and SUMO3. However, only overexpression of ATP5PO, coding for a component of the mitochondrial ATPase, led to significant reduction of ENS cells. Paradoxically, in vitro studies showed that overexpression of ATP5PO led to a reduction of ATP5PO protein levels. Impaired neuronal differentiation and reduced mitochondrial ATP production, were also detected in vitro, after overexpression of ATP5PO in a neuroblastoma cell line. Finally, epistasis was observed between ATP5PO and ret, the most important HSCR gene. Taken together, our results identify ATP5PO as the gene responsible for the increased risk of HSCR in DS patients in particular if RET variants are also present, and show that a balanced expression of ATP5PO is required for normal ENS development.

[Genome-wide diagnostics; after the results the real work begins]. / Genoombrede diagnostiek.

Introduction of new genetic test technologies in the last decade have accelerated genetic diagnosis in many medical specialties and have increased diagnostic yield considerably. SNP-arrays have been established as first tier diagnostic tools, more and more being replaced by next generation sequencing strategies, like targeted genomic panels and whole exome sequencing. We present the diagnostic work-up of a clinical case, a girl with congenital vertebral and rib anomalies. This case illustrates the complexity of genetic tests and the need for knowledge and experience to interpret the results. Intensive collaboration between pediatrician, clinical geneticist and laboratory specialist is mandatory, as is long-term commitment to involve parents in the diagnostic journey .

A middle stone age worked bone industry from Katanda, Upper Semliki Valley, Zaire.

Three archaeological sites at Katanda on the Upper Semliki River in the Western Rift Valley of Zaire have provided evidence for a well-developed bone industry in a Middle Stone Age context. Artifacts include both barbed and unbarbed points as well as a daggerlike object. Dating by both direct and indirect means indicate an age of approximately 90,000 years or older. Together with abundant fish (primarily catfish) remains, the bone technology indicates that a complex subsistence specialization had developed in Africa by this time. The level of behavioral competence required is consistent with that of upper Paleolithic Homo sapiens sapiens. These data support an African origin of behaviorally as well as biologically modern humans.

Dating pleistocene archeological sites by protein diagenesis in ostrich eggshell.

Eggshells of the African ostrich (Struthio camelus), ubiquitous in archeological sites in Africa, have been shown by laboratory simulation experiments to retain their indigenous organic matrix residues during diagenesis far better than any other calcified tissue yet studied. The rate of L-isoleucine epimerization to D-alloisoleucine follows reversible first-order kinetics and has been calibrated for local temperature effects and used to estimate the age range of stratified archeological sites. Age estimates are consistent with radiocarbon dates from several stratified archeological sites. With adequate calibration, this technique can provide accurate ages to within 10 to 15 percent for strata deposited within the last 200,000 years in the tropics and the last 1,000,000 years in colder regions such as China.

Dating and context of three middle stone age sites with bone points in the Upper Semliki Valley, Zaire.

The extent to which the earliest anatomically modern humans in Africa exhibited behavioral and cognitive traits typical of Homo sapiens sapiens is controversial. In eastern Zaire, archaeological sites with bone points have yielded dates older than 89(-15)+22 thousand years ago by several techniques. These include electron spin resonance, thermoluminescence, optically stimulated luminescence, uranium series, and amino acid racemization. Faunal and stratigraphic data are consistent with this age.

Hirschsprung disease, associated syndromes and genetics: a review.

Hirschsprung disease (HSCR, aganglionic megacolon) represents the main genetic cause of functional intestinal obstruction with an incidence of 1/5000 live births. This developmental disorder is a neurocristopathy and is characterised by the absence of the enteric ganglia along a variable length of the intestine. In the last decades, the development of surgical approaches has importantly decreased mortality and morbidity which allowed the emergence of familial cases. Isolated HSCR appears to be a non-Mendelian malformation with low, sex-dependent penetrance, and variable expression according to the length of the aganglionic segment. While all Mendelian modes of inheritance have been described in syndromic HSCR, isolated HSCR stands as a model for genetic disorders with complex patterns of inheritance. The tyrosine kinase receptor RET is the major gene with both rare coding sequence mutations and/or a frequent variant located in an enhancer element predisposing to the disease. Hitherto, 10 genes and five loci have been found to be involved in HSCR development.

A novel susceptibility locus for Hirschsprung's disease maps to 4q31.3-q32.3.

We report on a multigenerational family with isolated Hirschsprung's disease (HSCR). Five patients were affected by either short segment or long segment HSCR. The family consists of two main branches: one with four patients (three siblings and one maternal uncle) and one with one patient. Analysis of the RET gene, the major gene involved in HSCR susceptibility, revealed neither linkage nor mutations. A genome wide linkage analysis was performed, revealing suggestive linkage to a region on 4q31-q32 with a maximum parametric multipoint LOD score of 2.7. Furthermore, non-parametric linkage (NPL) analysis of the genome wide scan data revealed a NPL score of 2.54 (p = 0.003) for the same region on chromosome 4q (D4S413-D4S3351). The minimum linkage interval spans a region of 11.7 cM (12.2 Mb). No genes within this chromosomal interval have previously been implicated in HSCR. Considering the low penetrance of disease in this family, the 4q locus may be necessary but not sufficient to cause HSCR in the absence of modifying loci elsewhere in the genome. Our results suggest the existence of a new susceptibility locus for HSCR at 4q31.3-q32.3.

9-(5-Carboxypentylamino)-acridine. An affinity adsorbent ligand for Electrophorus acetylcholinesterase.

We have developed a simple method for the synthesis of the ligand 9-(5-carboxypentylamino)-acridine and the resulting affinity adsorbent using Sepharose CL-4B. This affinity adsorbent is efficient and specific for purification acetylcholinesterase (acetylcholine acetylhydrolase, EC 3.1.1.7) from Electrophorus electricus electric organ.

Purification and binding properties of porcine plasma ficolin that binds Actinobacillus pleuropneumoniae.

Previous studies demonstrated that porcine plasma ficolin binds the important pig pathogen Actinobacillus pleuropneumoniae (APP) in an N-acetylglucosamine-dependent manner. In the present study, attempts to characterize the bacterial-binding properties of ficolin indicated ficolin is the major porcine plasma protein that binds directly to epoxy-activated chromatography matrices. We developed an efficient method for purifying ficolin using epoxy-activated Toyopearl and compared these with forms retrieved from other chromatography matrices and from intact APP. Purified ficolins retained their GlcNAc- and bacterial-binding properties, and migrated as two high molecular weight multimers composed of 38, 40 and 42 kDa reduced forms (pI 5.2-6.0). An N-acetylated amine-activated Toyopearl matrix bound ficolin, and ficolin was dissociated from this matrix with acetamide. Acetate, acetamide, and GlcNAc, but not glucose or glucosamine, dissociated plasma ficolin from the surface of intact APP serotype 5b, which contains N-acetylated saccharides in the capsule. These studies indicate that porcine ficolin binds APP 5b and an N-acetylated matrix in a similar manner, supporting the view that N-acetyl groups may be important for binding of porcine plasma ficolin to some microbial surfaces.

Unexpected life-threatening complications in Kabuki syndrome.

Kabuki syndrome is a rare multiple congenital anomalies/mental retardation syndrome comprising a distinct facial appearance and fetal fingertip pads. We observed two patients with Kabuki syndrome and describe unusual life-threatening complications, including stenosis of the central airways (not previously reported), extrahepatic biliary atresia, and congenital diaphragmatic hernia.

[From gene to disease: arteriohepatic dysplasia or Alagille syndrome]. / Van gen naar ziekte; arteriohepatische dysplasie--het syndroom van Alagille.

Alagille syndrome (AGS), also known as arteriohepatic dysplasia, is an autosomal dominant disorder with a prevalence of approximately one in 70,000 live births. AGS is characterised by intrahepatic bile duct paucity and other developmental abnormalities affecting the heart, liver, eyes, vertebrae and the craniofacial region. Mutations in the JAG1 gene have been demonstrated to cause Alagille syndrome. JAG1 encodes a cellular membrane-bound ligand for the Notch receptor and is expressed during the normal development of tissues affected in Alagille syndrome. JAG1 mutations are detected in approximately 70% of AGS patients and are mostly protein truncating mutations. JAG1 mutations have also been described in patients that do not demonstrate the complete AGS phenotype, suggesting that the phenotypic spectrum of JAG1 mutations is broader than thus far assumed.

[Genes and genetics in Hirschsprung's disease]. / Genen en genetica bij de ziekte van Hirschsprung.

Hirschsprung's disease (HSCR) is a congenital disorder characterized by intestinal obstruction due to the absence of intramural ganglia along variable lengths of the colon. Occurrence among family members and recurrence risks among siblings are indications for involvement of genetic predispositions. Mutations have been discovered in five different susceptibility genes. One of the most important findings is the detection of specific mutations in the so-called RET gene, which can also be responsible for the multiple endocrine neoplasia type 2A (MEN2A) syndrome. HSCR patients with such specific mutations run an increased risk of developing MEN type 2A related tumours.

Single nucleotide polymorphisms in collagenous lectins and other innate immune genes in pigs with common infectious diseases.

Innate immune recognition of pathogens involves various surface receptors and soluble proteins that precede agglutination, complement activation, phagocytosis, and the adaptive immune response. Mannan-binding lectins (MBLs), ficolins (FCNs) and surfactant protein A (SP-A) are soluble collagenous lectins that bind surface structures of various bacteria, viruses and fungi. Some single nucleotide polymorphisms (SNPs) in collagenous lectin genes of humans and other species, including pigs, have been implicated in variation in susceptibility to infectious and inflammatory diseases. In this study we determined the frequencies of 13 SNP alleles of MBL-A, MBL-C, ficolin-α, ficolin-ß, and SP-A in 1324 healthy pigs and 461 pigs diagnosed with common infectious diseases at necropsy. For comparison, we also analyzed 12 other SNP alleles in several other innate immune genes, including galectins and TLRs. Several SNPs within genes encoding porcine MBL-A, MBL-C and SP-A were more frequent in pigs diagnosed at necropsy with various diseases or pathogens. These findings suggest that several collagenous lectin SNPs are associated with disease susceptibility and therefore might be genetic markers of impaired innate immune function.

Studying the genetics of Hirschsprung's disease: unraveling an oligogenic disorder.

Hirschsprung's disease is characterized by the absence of ganglion cells in the myenteric and submucosal plexuses of the gastrointestinal tract. Genetic dissection was successful as nine genes and four loci for Hirschsprung's disease susceptibility were identified. Different approaches were used to find these loci such as classical linkage in large families, identity by descent mapping in an inbred kindred, candidate gene approaches based on naturally occurring mutant mice models, and finally the use of model-free linkage and association analyzes. In this study, we review the identification of genes and loci involved in the non-syndromic common form and syndromic Mendelian forms of Hirschsprung's disease. The majority of the identified genes are related to Mendelian syndromic forms of Hirschsprung's disease. The non-Mendelian inheritance of sporadic non-syndromic Hirschsprung's disease proved to be complex; involvement of multiple loci was demonstrated in a multiplicative model. We discuss the practical implications of the elucidation of genes associated with Hirschsprung's disease susceptibility for genetic counseling. Finally, we speculate on possible strategies to identify new genes for Hirschsprung's disease.

Selenium compounds in the fathead minnow (Pimephales promelas)--I. Uptake, distribution, and elimination of orally administered selenate, selenite and l-selenomethionine.

Treatment of fathead minnows (Pimephales promelas) with either [75Se]selenate, -selenite or -l-selenomethionine by gavage at 20 ng Se/g resulted in organ uptake and early distribution patterns which differed significantly between compounds. The greatest differences in uptake between compounds was observed in liver tissue which accumulated much less [75Se]selenate than either selenite or l-selenomethionine. The 75Se burdens and relative distribution among the various organs were nearly identical during the elimination phase for [75Se]selenate and -selenite. This suggests that selenium derived from these compounds converge to a common metabolic pool. The whole body T1/2, rate of 75Se uptake and magnitude of 75Se accumulation were generally greater for [75Se]selenomethionine than the inorganic forms. Selenium-75 was present in the bile following the oral administration of each compound. The partitioning of selenate and selenite into the plasma and cellular fraction of blood differs with both the compound and time following exposure.

Selenium compounds in the fathead minnow (Pimephales promelas)--II. Quantitative approach to gastrointestinal absorption, routes of elimination and influence of dietary pretreatment.

Following administration by gavage [75Se]selenate and [75Se]selenite were absorbed from the gastrointestinal tract of fathead minnows (Pimephales promelas) at 94 and 80% efficiency, respectively. Approximately 12% of the [75Se]selenate administered by i.p. injection was eliminated via the urine, and across the gill within 2 hr. The urine was the primary route of elimination followed by the gill. The bile contained significantly lower amounts of 75Se than that eliminated either across the gill or in the urine. The mucus is capable of binding significant amounts of 75Se. Dietary pretreatment with selenite reduced the retention of a subsequent [75Se]selenite dose administered by gavage.

The revolution that wasn't: a new interpretation of the origin of modern human behavior.

Proponents of the model known as the "human revolution" claim that modern human behaviors arose suddenly, and nearly simultaneously, throughout the Old World ca. 40-50 ka. This fundamental behavioral shift is purported to signal a cognitive advance, a possible reorganization of the brain, and the origin of language. Because the earliest modern human fossils, Homo sapiens sensu stricto, are found in Africa and the adjacent region of the Levant at >100 ka, the "human revolution" model creates a time lag between the appearance of anatomical modernity and perceived behavioral modernity, and creates the impression that the earliest modern Africans were behaviorally primitive. This view of events stems from a profound Eurocentric bias and a failure to appreciate the depth and breadth of the African archaeological record. In fact, many of the components of the "human revolution" claimed to appear at 40-50 ka are found in the African Middle Stone Age tens of thousands of years earlier. These features include blade and microlithic technology, bone tools, increased geographic range, specialized hunting, the use of aquatic resources, long distance trade, systematic processing and use of pigment, and art and decoration. These items do not occur suddenly together as predicted by the "human revolution" model, but at sites that are widely separated in space and time. This suggests a gradual assembling of the package of modern human behaviors in Africa, and its later export to other regions of the Old World. The African Middle and early Late Pleistocene hominid fossil record is fairly continuous and in it can be recognized a number of probably distinct species that provide plausible ancestors for H. sapiens. The appearance of Middle Stone Age technology and the first signs of modern behavior coincide with the appearance of fossils that have been attributed to H. helmei, suggesting the behavior of H. helmei is distinct from that of earlier hominid species and quite similar to that of modern people. If on anatomical and behavioral grounds H. helmei is sunk into H. sapiens, the origin of our species is linked with the appearance of Middle Stone Age technology at 250-300 ka.

Macronuclear differentiation during oral regeneration in Stentor coeruleus.

The moniliform macronucleus of Stentor coeruleus coalesces and renodulates during division, reorganization and regeneration. These nuclear events are spatially and temporally synchronized with oral primordium development occurring at stages six and seven of membranellar morphogenesis. Coalesced, elongating and early renodulating macronuclei at states six and seven contained microtubules within double membrane-bound channels, passing through the nucleus parallel to the long axis. The number of microtubules per channel varied between 4 and 23. Microtubules were also found in the perinuclear cytoplasm at these stages, forming a loose network around the nucleus. The microtubules and channels are absent in control cells and macronuclei of regenerating cells prior to stage six. These transient microtubules and channels appearing in late stage six and stage seven may provide the axial plane on which elongation of the macronucleus proceeds.