Genetic and environmental interactions determine seizure susceptibility in epileptic EL mice

Gene identification has progressed rapidly for monogenic epilepsies, but complex gene-environmental interactions have hindered progress in gene identification for multifactorial epilepsies. We analyzed the role of environmental risk factors in the inheritance of multifactorial idiopathic generalized epilepsy in the EL mouse. Seizure susceptibility was evaluated in the EL (E) and seizure-resistant ABP/LeJ (A) parental mouse strains and in their AEF1 and AEF2 hybrid offspring using a handling-induced seizure test. The seizure test was administered in three environments (environments I, II and III) that differed with respect to the number of seizure tests administered (one test or four tests) and the age of the mice when tested (young or old). The inheritance of seizure susceptibility appeared dominant after repetitive seizure testing in young or old mice, but recessive after a single test in old mice. Heritability was high (0.67-0.77) in each environment. Significant quantitative trait loci (QTL) that were associated with environments I and III (repetitive testing) were found on chromosomes 2 and 9 and colocalized with previously mapped El2 and El4, respectively. The El2 QTL found in environment I associated only with female susceptibility. A novel QTL, El-N, for age-dependent predisposition to seizures was found on proximal chromosome 9 only in environment II. The findings indicate that environmental risk factors determine the genetic architecture of seizure susceptibility in EL mice and suggest that QTL for complex epilepsies should be defined in terms of the environment in which they are expressed.     

Segregation Analysis on Genetic System of Quantitative Traits in Plants

Based on the traditional polygene inheritance model of quantitative traits,the author suggests the major gene and polygene mixed inheritance model.The model was considered as a general one,while the pure major gene and pure polygene inheritance model was a specific case of the general model.Based on the proposed theory,the author established the segregation analysis procedure to study the genetic system of quantitative traits of plants.At present,this procedure can be used to evaluate the genetic effect of individual major genes (up to two to three major genes),the collective genetic effect of polygene,and their heritability value.This paper introduces how to establish the procedure,its main achievements,and its applications.An example is given to illustrate the steps,methods,and effectiveness of the procedure.     

Characterization of microsatellite loci in silver carp (Hypophthalmichthys molitrix), and cross‐amplification in other cyprinid species

Captive populations of silver carp (Hypophthalmichthys molitrix), a major aquaculture species in Asia, would undoubtedly benefit from genetic monitoring and improvement programs. We report the isolation and preliminary characterization of 16 microsatellite loci derived from both conventional and microsatellite‐enriched libraries. Inheritance studies confirmed the allelic nature of observed polymorphisms at all loci, while identifying null alleles at two loci. These loci, having varying degrees of polymorphism, should provide useful markers for applied genetic studies. A high degree of cross‐amplification among 10 other cyprinid species suggests that these loci may have more widespread utility.     

Oculo-facio-cardio-dental syndrome in a girl and her mother

Congenital heart defects are known to be associated with facial dysmorphism and other congenital anomalies. Oculo-facio-cardio-dental (OFCD) syndrome is one such rare multiple congenital anomaly syndrome inherited as an X-linked dominant condition characterized by congenital cataracts, multiple minor facial dysmorphic features, congenital heart defects and dental anomalies. It is unrecognized by many medical and dental professionals. Only 21 cases have been reported so far. This syndrome is often misrecognized as rubella embryopathy because of association of congenital cataract with cardiac anomalies. It is usually the orthodontists who diagnose the syndrome based on typical findings on dental panoramic radiographs. But we suspected our patient to be having OFCD syndrome based on typical facial dysmorphism, ocular and cardiac defects, and finally it was confirmed after noticing typical dental radiographic findings.     

不同寄主来源的串珠镰孢生物学性状及其在无性后代的遗传与变异

自安徽、山东、湖北、江苏等地多点采集棉花红腐病、水稻恶苗病、玉米穗腐病的病组织,经分离、鉴定和纯化,获得107个串珠镰孢（Fusarium monilifoFine）菌株。对上述来源于棉花、水稻、玉米的串珠镰孢的菌落形态、生长速率和产孢量等生物学性状及其在无性后代的遗传与变异进行了研究。结果表明,不同寄主来源的串珠镰孢菌株的菌丝生长温度范围和最适温度大致相同,但在菌落形态特别是色素方面存在明显差异,生长速率和产孢量也存在显著差异。棉花菌株的平均生长速率最大,玉米菌株生长速率最小,水稻菌株生长速率居中,相同群体的不同菌株间生长速率有极显著差异;玉米菌株产孢量最大,棉花菌株产孢量最小,水稻菌株产孢量居中。方差分析显示,不同寄主菌株群体间产孢量存在显著差异,而同一寄主群体的不同菌株间产孢量均无显著差异,说明菌株产孢量大小主要与其寄主种类有关,而与地区来源关系不大。遗传测定结果表明,分离自棉花、玉米和水稻的串珠镰孢的菌落形态和生长速率在单分生孢子后代均可稳定遗传;产孢量性状遗传有两种情况：分离自棉花和水稻的串珠镰孢菌株Fm1和Fm31的产孢量性状在单分生孢子后代均可稳定遗传,而分离白玉米的串珠镰孢菌株Fm19的产孢量性状在单分生孢子第一代（CG1）发生变异。     

Lens‐anomalies and other ophthalmic findings in a group of closely‐related angola lions (Panthera leo bleyenberghi)

After the diagnosis of bilateral, immature, nuclear, and posterior cortical cataracts in one Angola lioness, and because of the possible implications of the cataracts for a breeding program, complete ophthalmic examinations on a group of related adult Angola lions and their offspring were carried out. Five adult lions, ranging in age from 1.5–5.5 years, and five lion cubs were studied clinically. The examination included slit‐lamp biomicroscopy, indirect ophthalmoscopy, and photography. The eyes of three of the offspring were submitted for histopathologic examination and examined by light microscopy. The most significant findings were cataracts of various stages, which were observed in four adult lions and one male cub. Mild lenticular abnormalities were noted in the histopathologic examination of the lion cubs' eyes. Additional ophthalmic findings, of lesser clinical consequence, were also noted. This breeding program would benefit from further investigation by animal nutritionists and geneticists, and the animals in this group should undergo periodic ophthalmologic examinations. Zoo Biol 0:1–7, 2006. © 2006 Wiley‐Liss, Inc.     

Copy number variations (CNVs) in human pluripotent cell-derived neuroprogenitors

Results from the analysis of copy number variations (CNVs) in human pluripotent cell-derived neuroprogenitor cell lines (hiPSC and hESC-derived NPC) are presented. Two different types of CNVs were detected: a) CNVs inherited from the original source of pluripotent cells (hESC and hiPSC) and b) CNVs detected either in the original source of pluripotent cells or in the derived NPC cell lines but not in both at the same time. Our data suggest that submicroscopic chromosomal changes happened during culture and manipulation of cells and those differentiation procedures could result in gains and losses of genomic regions in pluripotent cell-derived neuroprogenitors. Overall, the results indicate that even chromosomally stable stem cell lines would need to be analyzed in detail by high resolution methodologies before their clinical use.     

Non-invasive prenatal diagnosis of single-gene disorders from maternal blood

Prenatal diagnosis (PD) is available for pregnancies at risk of monogenic disorders. However, PD requires the use of invasive obstetric techniques for fetal-sample collection and therefore, involves a risk of fetal loss. Circulating fetal DNA in the maternal bloodstream is being used to perform non-invasive prenatal diagnosis (NIPD). NIPD is a challenging discipline because of the biological features of the maternal blood sample. Maternal blood is an unequal mixture of small (and fragmented) amounts of fetal DNA within a wide background of maternal DNA. For this reason, initial NIPD studies have been based on the analysis of specific paternally inherited fetal tracts not present in the maternal genome so as to ensure their fetal origin. Following this strategy, different NIPD studies have been carried out, such as fetal-sex assessment for pregnancies at risk of X-linked disorders, RhD determination, and analysis of single-gene disorders with a paternal origin. The study of the paternal mutation can be used for fetal diagnosis of dominant disorders or to more accurately assess the risk of an affected child in case of recessive diseases. Huntington's disease, cystic fibrosis, or achondroplasia are some examples of diseases studied using NIPD. New technologies are opening NIPD to the analysis of maternally inherited fetal tracts. NIPD of trisomy 21 is the latest study derived from the use of next-generation sequencing (NGS).