Holoprosencephaly in a fetal macaque (Macaca nemestrina) following weekly exposure to ethanol

Previous studies in rodents have indicated that the facial changes of fetal alcohol syndrome (FAS) closely resemble those of a mild form of holoprosencephaly. In order to examine this relationship in non-human primates, we evaluated a 133-day gestation macaque (Macaca nemestrina) with holoprosencephaly, median cleft lip and palate, and encephalocele. The mother had been given ethanol once per week (1.8 g/kg body weight) from weeks 2 to 19 postconception. Diagnosis of holoprosencephaly was made following ultrasound evaluation for polyhydramnios and delivery of the female fetus by caesarean section. Another fetus of identical age was delivered by caesarean section for use as a control. Both fetuses were studied by anthropometric, gross, radiographic, and histologic techniques. In the fetus exposed to alcohol, no extracranial anomalies were identified and the karyotype was normal. The brain was micrencephalic, with absent olfactory bulbs, tracts, optic nerves and chiasma, fused frontal lobes, and a single, dilated lateral ventricle; a parietooccipital encephalocele consisted of thin, dysplastic cortex bordering the ventricle; the cerebellum was dysplastic and superiorly displaced. Within the craniofacial complex, anophthalmia was bilateral; premaxillary components were absent, palatal shelves separate, the maxillae closeset, and the ethmoid bone small and deformed. Most of these defects are similar to those encountered in humans with holoprosencephaly and support the hypothesis of shared etiologic and pathogenetic relations between the facial anomalies of fetal alcohol syndrome and holoprosencephaly.     

On the association profound nerve deafness, semilobar holoprosencephaly, and minor midline developmental anomalies

A two-year-old boy with the combination of profound nerve deafness and semilobar holoprosencephaly associated with minor midline developmental anomalies is reported. In a review of the literature we could not find other examples of this possible syndromic association.     

Holoprosencephaly: clinical, anatomic, and molecular dimensions

Holoprosencephaly is addressed under the following headings: alobar, semilobar, and lobar holoprosencephaly; arrhinencephaly; agenesis of the corpus callosum; pituitary abnormalities; hindbrain abnormalities; syntelencephaly; aprosencephaly/atelencephaly; neural tube defects; facial anomalies; median cleft lip; minor facial anomalies; single maxillary central incisor; holoprosencephaly-like phenotype; epidemiology; genetic causes of holoprosencephaly; teratogenic causes of holoprosencephaly; SHH mutations; ZIC2 mutations; SIX3 mutations; TGIF mutations; PTCH mutations; GLI2 mutations; FAST1 mutations; TDGF1 mutations; and DHCR7 mutations.     

A case of methotrexate embryopathy with holoprosencephaly, expanding the phenotype

BACKGROUND: Methotrexate (MTX) embryopathy was described nearly 50 years ago, when this agent began to be used as a cancer treatment and abortifacient. In this report we describe a case with typical features of MTX syndrome together with new features to expand the phenotype. CASE: A 29-year-old woman decided to terminate her unwanted pregnancy because of ill health, as she had conceived soon after her last delivery by cesarian section. At 6 weeks of gestation, she took 2.5 mg of MTX 3 times a day for 7 days. The pregnancy termination failed, and the pregnancy was carried to term. A female infant was delivered who was growth retarded and had characteristic features of MTX embryopathy in addition to holoprosencephaly and other brain malformations, facial hypertrichosis, and long eyelashes-features that have not hitherto been described. CONCLUSIONS: We report the first case of holoprosencephaly in association with MTX exposure during the first 6 weeks of gestation. Physicians and the public should be aware of the effects of MTX on the fetus during pregnancy.     

Selected clinical research involving the central nervous system

This paper updates three clinical research projects involving the central nervous system. Discussions of conditions with encephalocele include several associations: encephalocele/craniostenosis, transsphenoidal encephalocele/hypothalamic-pituitary dysfunction, encephalocele/oculo-auriculo-vertebral spectrum, and encephalocele/frontonasal dysplasia. The relationship between oculo-auriculo-vetebral spectrum with encephalocele and frontonasal dysplasia with epibulbar dermoids and ear tags is also discussed and an explanation for encephalocele formation in the Apert syndrome is provided. Studies of the central nervous system in Apert syndrome indicate that distortion ventriculomegaly is common, but progressive hydrocephalus occurs infrequently. A recurrent pattern of abnormalities was discerned consisting of megalencephaly, gyral abnormalities, and defects of the corpus callosum and limbic structures. Five neuropathologic studies lend further support to this pattern of CNS anomalies in the Apert syndrome. In a study of holoprosencephaly, eight principles governing associated facial dysmorphism were derived. Each diagnostic category was shown to have its own frequency and range of holoprosencephalic faces. Some categories, such as del(13q), have narrow ranges; others, such as trisomy 13 syndrome, have broad ranges. However, no broad diagnostic range is known to include agnathia-holoprosencephaly and other severe forms of facial dysmorphism without agnathia. Absent maxillary incisors and a single maxillary central incisor are extremely common in holoprosencephaly with severe facial dysmorphism and may occur on occasion as a striking microform of holoprosencephaly, most commonly in the autosomal dominant form.     

The Ubiquitin E3 Ligase NOSIP Modulates Protein Phosphatase 2A Activity in Craniofacial Development

Holoprosencephaly is a common developmental disorder in humans characterised by incomplete brain hemisphere separation and midface anomalies. The etiology of holoprosencephaly is heterogeneous with environmental and genetic causes, but for a majority of holoprosencephaly cases the genes associated with the pathogenesis could not be identified so far. Here we report the generation of knockout mice for the ubiquitin E3 ligase NOSIP. The loss of NOSIP in mice causes holoprosencephaly and facial anomalies including cleft lip/palate, cyclopia and facial midline clefting. By a mass spectrometry based protein interaction screen we identified NOSIP as a novel interaction partner of protein phosphatase PP2A. NOSIP mediates the monoubiquitination of the PP2A catalytic subunit and the loss of NOSIP results in an increase in PP2A activity in craniofacial tissue in NOSIP knockout mice. We conclude, that NOSIP is a critical modulator of brain and craniofacial development in mice and a candidate gene for holoprosencephaly in humans.     

Perspectives on holoprosencephaly: Part II. Central nervous system, craniofacial anatomy, syndrome commentary, diagnostic approach, and experimental studies.

This paper presents an updated analytic review of the holoprosencephalic disorders. Central nervous system findings and craniofacial anatomy are discussed in depth. Associated anomalies and syndromes are updated with a syndrome commentary that attempts to separate durable syndromes from associated anomalies and spurious entities. The differential diagnosis of various conditions that may simulate the holoprosencephalic disorders is also discussed. Various experimental approaches to holoprosencephaly are reviewed, indicating that holoprosencephaly appears to be both etiologically and pathogenetically heterogeneous.     

Cerebral midline developmental anomalies: spectrum and associated features

Cerebral midline anomalies are defects of anatomical relationships between the two hemispheres. They include holoprosencephalies, septal and commissural agenesis. Agenesis of the olfactory tract (arhinencephalies) are often included in the spectrum of holoprosencephalies and the facial phenotype is thought to be affected and characteristic in the midline development abnormalities. This work concerns a review of the literature and personal experience in two units of Fetopathology in Paris. This study confirms the relationships between various cerebral malformations and their frequent association. However, arhinencephaly and moreover agenesis of corpus callosum should be considered as heterogeneous entities, often totally distinct and independent from the malformative process of the holoprosencephaly. In addition, if major facial anomalies such as cyclopia are almost pathognomonic for holoprosencephaly, minor malformations such as lateral facial clefts of cleft palates result from a great variety of malformative processes.     

Craniofacial anomalies: from development to molecular pathogenesis

Advances in developmental biology combined with progress in human genetics are helping us decipher how the craniofacial region develops and how the consequences of misdirected development result in malformation. This review describes the molecular etiology of a number of craniofacial developmental anomalies. The more common craniofacial anomalies cleft lip and palate and craniosynostosis, as well as cleidocranial dysplasia, hemifacial microsomia, holoprosencephaly, enlarged parietal foramina, Treacher Collins syndrome and cherubism are discussed.     

植物保护遗传学研究进展

保护遗传学是过用遗传学的原理和研究手段,以生物多样性尤其是遗传多样性的研究和保护为核心的一门新兴学科,近几十年来,遗传学研究在生物多样性保护的理论和实践中发挥着越来越重要的作用。本文简要回顾了保护遗传学的发展历史,研究方向和涉及的概念,着重介绍了植物保护遗传学研究所取得的一些进展,包括植物系统发育重建和保护单元的确定,遗传多样性与物种和群体适应性之间的关系,群体遗传结构与保护策略的制定以及植物遗传资源的鉴定和利用等方面的内容,并强调保护遗传学研究是未来生物多样性和保护生物学研究中一个亟待加强的研究领域。     

Conservation genetics in a globally changing environment: present problems,paradoxes and future challenges

Despite recent advances in conservation genetics and related disciplines and the growing impact that conservation genetics is having in conservation biology, our knowledge on several key issues in the field is still insufficient. Here we identify some of these issues together with addressing several paradoxes which have to be solved before conservation genetics can face new challenges that are appearing in the transitory phase from the population genetics into the population genomics era. Most of these issues, paradoxes and challenges, like the central dogma of conservation genetics, the computational, theoretical and laboratory experiment achievements and limitations in the conservation genetics field have been discussed. Further knowledge on the consequences of inbreeding and outbreeding depression in wild populations as well as the capacity of small populations to adapt to local environmental conditions is also urgently needed. The integration of experimental, theoretical and applied conservation genetics will contribute to improve our understanding of methodological and applied aspects of conservation genetics.     

短指/趾的分子遗传学研究进展

短指/趾(Brachydactyly, BD)是指(趾)骨和/或掌(跖)骨短小、缺失或融合导致的手/足先天畸形, 是一组以骨发育障碍为特征的肢体畸形疾病。BD可单独出现, 也可作为综合征的一种体征, 还可伴随其他的手/足畸形如并指/趾、多指/趾、短缺畸形和指/趾骨关节融合出现。绝大多数单纯型BD呈常染色体显性遗传, 存在表现度不同和外显不全。大多数单纯型BD和一些综合征型BD的致病基因缺陷已经被鉴定。BMP (Bone morphogenetic protein)通路参与正常指/趾发育, 且已知的BD致病基因直接或间接参与该通路。文章综述了BD分子遗传学研究方面的新进展, 将有助于BD致病机制的研究和基因诊疗的开展。     

Aberrant forebrain signaling during early development underlies the generation of holoprosencephaly and coloboma

In this review, we highlight recent literature concerning the signaling mechanisms underlying the development of two neural birth defects, holoprosencephaly and coloboma. Holoprosencephaly, the most common forebrain defect, occurs when the cerebral hemispheres fail to separate and is typically associated with mispatterning of embryonic midline tissue. Coloboma results when the choroid fissure in the eye fails to close. It is clear that Sonic hedgehog (Shh) signaling regulates both forebrain and eye development, with defects in Shh, or components of the Shh signaling cascade leading to the generation of both birth defects. In addition, other intercellular signaling pathways are known factors in the incidence of holoprosencephaly and coloboma. This review will outline recent advances in our understanding of forebrain and eye embryonic pattern formation, with a focus on zebrafish studies of Shh and retinoic acid pathways. Given the clear overlap in the mechanisms that generate both diseases, we propose that holoprosencephaly and coloboma can represent mild and severe aspects of single phenotypic spectrum resulting from aberrant forebrain development. This article is part of a Special Issue entitled Zebrafish Models of Neurological Diseases.     

Lobar holoprosencephaly and Xq22 deletion.

A 20 weeks gestation female fetus with a lobar holoprosencephaly and Xq22 deletion is described. The phenotype correlation of the cerebral defect with the facial features is positive. On the contrary phenotypic-karyotypic correlation is non obvious.     

Aspects of Facial Contrast Decrease with Age and Are Cues for Age Perception

Age is a primary social dimension. We behave differently toward people as a function of how old we perceive them to be. Age perception relies on cues that are correlated with age, such as wrinkles. Here we report that aspects of facial contrast–the contrast between facial features and the surrounding skin–decreased with age in a large sample of adult Caucasian females. These same aspects of facial contrast were also significantly correlated with the perceived age of the faces. Individual faces were perceived as younger when these aspects of facial contrast were artificially increased, but older when these aspects of facial contrast were artificially decreased. These findings show that facial contrast plays a role in age perception, and that faces with greater facial contrast look younger. Because facial contrast is increased by typical cosmetics use, we infer that cosmetics function in part by making the face appear younger.     

Angiosperm ovules: diversity, development, evolution

Background

Ovules as developmental precursors of seeds are organs of central importance in angiosperm flowers and can be traced back in evolution to the earliest seed plants. Angiosperm ovules are diverse in their position in the ovary, nucellus thickness, number and thickness of integuments, degree and direction of curvature, and histological differentiations. There is a large body of literature on this diversity, and various views on its evolution have been proposed over the course of time. Most recently evo–devo studies have been concentrated on molecular developmental genetics in ovules of model plants.

Scope

The present review provides a synthetic treatment of several aspects of the sporophytic part of ovule diversity, development and evolution, based on extensive research on the vast original literature and on experience from my own comparative studies in a broad range of angiosperm clades.

Conclusions

In angiosperms the presence of an outer integument appears to be instrumental for ovule curvature, as indicated from studies on ovule diversity through the major clades of angiosperms, molecular developmental genetics in model species, abnormal ovules in a broad range of angiosperms, and comparison with gymnosperms with curved ovules. Lobation of integuments is not an atavism indicating evolution from telomes, but simply a morphogenetic constraint from the necessity of closure of the micropyle. Ovule shape is partly dependent on locule architecture, which is especially indicated by the occurrence of orthotropous ovules. Some ovule features are even more conservative than earlier assumed and thus of special interest in angiosperm macrosystematics.     

How to teach procedures,problem solving,and concepts in microbial genetics

Flow diagrams, algorithms, decision logic tables, and concept maps are presented as methods for teaching practical procedures, problem solving, and basic concepts in microbial genetics. For practical procedures the aim is to present the sequence of operations clearly, to diagnose and correct possible errors, and to encourage the student to design investigations efficiently. Procedures for problem solving are discussed which give a logical sequence of questions with yes/no answers leading to a finite number of possible solutions. The use of concept maps in the planning of courses and in illustrating the relationships between different aspects of microbial genetics is discussed. It is suggested that the flexible use of these methods should lead to an improved understanding of microbial genetics.     

Proboscis lateralis: a case report

A lateral proboscis usually occurs in the region of the inner canthus. We present a case of holoprosencephaly accompanied by an oblique facial cleft and an anterior encephalocele in which a proboscis lateralis occurred in a very lateral location.     

Microcephaly in familial holoprosencephaly

The holoprosencephaly sequence (HS) is characterized by abnormalities in forebrain cleavage and midface development. Familial holoprosencephaly has been reported in several families and there appears to be variable expression of the disorder in those who inherit the gene. Previous investigators have suggested hypotelorism and/or missing central incisors as mild manifestations of autosomal dominant HS. We evaluated a large kindred with three individuals with severe brain anomalies and 12 individuals with minor manifestations of the disorder. The most consistent sign in those mildly affected was microcephaly. We suggest that head circumference is an important part of the evaluation of the relatives of a patient with holoprosencephaly.     

植物分子生态学进展（II）——地理系统学、外来种、遗传保护及其它

从地理系统学、外来种、遗传保护、研究中的污染问题四个方面介绍了当前植物分子生态学的研究内容。分子标记在地理系统学的研究中有助于了解上一个冰期中物种避难地和冰期后的物种迁移路径;对于外来种,主要讨论了其通过杂交和渐渗杂交的方式适应新的环境;关于遗传保护,本文从四个方面强调了其重要性;除此之外,还介绍了分子生态学研究中不易察觉的污染问题并提示了转基因植物的生态影响。