Prevalence of chromosome 9 abnormalities among pediatric specimens / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To perform cytogenetic analysis for children, especially newborns suspected for chromosome abnormalities.</p><p><b>METHODS</b>Peripheral blood or born marrow specimens were respectively cultured in proper media. Karyograms were analyzed following G-banding.</p><p><b>RESULTS</b>Of 154 blood specimens, numerical chromosomal abnormalities were identified in 20 patients, which included 19 with trisomy 21. Structural aberrations were identified in 13 patients, among which chromosome 9 aberrations were seen in 6 cases. These included 3 inversions, 1 deletion, 1 insertion and 1 duplication. All aberrations were located in pericentromere region of chromosome 9 with clinical manifestations including congenital heart disease, peculiar facial appearance, paralysis, dysplasia and/or movement disorder. Chromosome polymorphisms were found in 20 patients, most of which had absence of satellites or variation of heterochromatin on chromosome 9. Of 10 bone marrow specimens from children suspected for acute leukemia, chromosome abnormalities were identified in 5 patients.</p><p><b>CONCLUSION</b>Cytogenetic analysis is useful for children featuring multiple congenital abnormalities. Chromosome 9 abnormalities and their clinical relevance should attract more attention.</p>

Identification of a genetic locus on chromosome 4q34-35 for type 2 diabetes with overweight

The incidence of type 2 diabetes is rising rapidly because of an increase in the incidence of being overweight and obesity. Identification of genetic determinants for complex diseases, such as type 2 diabetes, may provide insight into disease pathogenesis. The aim of the study was to investigate the shared genetic factors that predispose individuals to being overweight and developing type 2 diabetes. We conducted genome-wide linkage analyses for type 2 diabetes in 386 affected individuals (269 sibpairs) from 171 Korean families and association analyses with single-nucleotide polymorphisms of candidate genes within linkage regions to identify genetic variants that predispose individuals to being overweight and developing type 2 diabetes. Through fine-mapping analysis of chromosome 4q34-35, we detected a locus potentially linked (nonparametric linkage 2.81, logarithm of odds 2.27, P=6 x 10-4) to type 2 diabetes in overweight or obese individuals (body mass index, BMI> or =23 kg m-2). Multiple regression analysis with type 2 diabetes-related phenotypes revealed a significant association (false discovery rate (FDR) P=0.006 for rs13144140; FDR P=0.002 for rs6830266) between GPM6A (rs13144140) and BMI and waist-hip ratio, and between NEIL3 (rs6830266) and insulin level from 1314 normal individuals. Our systematic search of genome-wide linkage and association studies, demonstrate that a linkage peak for type 2 diabetes on chromosome 4q34-35 contains two type 2 diabetes-related genes, GPM6A and NEIL3.

A raça Gir Mocha na região Nordeste do Brasil: estrutura genética populacional via análise de pedigree / The Polled Gir Polled in Northeastern Brazil: population genetic structure via analysis of pedigree

Foram utilizados dados de pedigree de 2.558 bovinos da raça Gir Mocha nascidos no período de 1954 a 2005. As análises foram realizadas utilizando-se o programa Endog. Do total de animais estudados, 61,9%; 10,6% e 0,1% possuíam pedigree na primeira, segunda e terceira gerações, respectivamente.O número efetivo de rebanhos que forneceram machos reprodutores foi de 10,25 para pais e 3,87 para avôs, confirmando a baixa integralidade do pedigree. O número de animais fundadores foi de 975,5, e o número efetivo de fundadores de 141,34. O número de ancestrais na população referência foi de 924 animas, dos quais apenas 39 explicaram 50% da variabilidade genética da população.O coeficiente médio de relação foi estimado em 0,75%, sendo o maior coeficiente individual de 25%. O coeficiente de endogamia foi igual a zero de 1954 a 1984. Vale salientar que, neste período, estão incluídos os animais sem ascendência conhecida. A endogamia e o coeficiente médio de relação da população foram baixos, contudo podem estar subestimados em razão da pequena integralidade do pedigree.

In this study we used data from the 2558 pedigree cattle polled Gir born from 1954 to 2005. Analyses were performed using the Endog program. Of all animals studied, 61.86%, 10.56% and 0.10% had a pedigree in the first, second and third generation, respectively. The effective number of herds that provide breeding males was 10.25 for parents and 3.87 for grandparents, corroborating the low completeness of the pedigree. The number of founder animals was 975.5 and the effective number of founders were 141.34. The number of ancestors in the reference population was 924 animals from which only 39 accounted for 50% of the genetic variability of the population. The average relationship coefficient was estimated at 0.75%, the largest individual coefficient was 25%. The inbreeding coefficient was zero from 1954 to 1894. It is noteworthy that during this period included the population was low, but may be underestimated because of the small pedigree integrity.

Cloning, mapping and molecular characterization of porcine progesterone receptor membrane component 2 (PGRMC2) gene

Progesterone plays an important role in sow reproduction by stimulating classic genomic pathways via nuclear receptors and non-genomic pathways via membrane receptors such a progesterone receptor membrane component 2 (PGRMC2). In this work, we used radiation hybrid mapping to assign PGRMC2 to pig chromosome 8 and observed that this receptor has two transcripts in pigs. The full-length cDNA of the large transcript is 1858 bp long and contains a 669-bp open reading frame (ORF) encoding a protein of 223 amino acids. The shorter transcript encodes a protein of 170 amino acids. The porcine PGRMC2 gene consists of three exons 446 bp, 156 bp and 1259 bp in length. The promoter sequence is GC-rich and lacks a typical TATA box. Several putative cis-regulatory DNA motifs were identified in the 208-bp upstream genomic region. Five single nucleotide polymorphisms (SNPs) were detected in introns* and the 3' UTR. RT-PCR indicated that the PGRMC2 gene is expressed ubiquitously in all pig tissues examined.

Chromosome number and microsporogenesis of two accessions of Brachiaria dura Stapf (Poaceae) / Número de cromossomos e microsporogênese de dois acessos de Brachiaria dura Stapf (Poaceae)

The two accessions of B. dura analyzed (DU01 and DU02) are hexaploid (2n = 6x = 54), derived from x = 9. Meiotic abnormalities, such as precocious chromosome migration to the poles, laggards and micronuclei, were recorded in low frequency in both accessions. The few multivalent chromosome association at diakinesis and meiotic stability suggested that hexaploidy probably resulted from chromosome doubling. In DU02, chromosome transfer (cytomixis) among meiocytes, involving part or the entire genome was observed. The implication of these findings for the Brachiaria breeding is discussed.

Os dois acessos de B. dura analisados (DU01 e DU02) são hexaplóides (2n = 6x = 54), derivados de x = 9. Anormalidades meióticas como migração precoce de cromossomos para os polos, cromossomos retardatários e micronúcleos foram observados em baixa frequência em ambos os acessos. A presença de poucas associações cromossômicas em diacinese e a estabilidade meiótica sugere que a hexaploidia provavelmente resultou de duplicação cromossômica. No acesso DU02 observou-se transferência de cromossomos (citomixia) entre meiócitos, envolvendo parte ou todo o genoma. As implicações destes resultados para o melhoramento de Brachiaria são discutidas.

Chromosomal localization of foreign genes in transgenic mice using dual-color fluorescence in situ hybridization / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To establish a highly sensitive and specific dual-color fluorescence in situ hybridization (D-FISH) method used for chromosomal localization of foreign genes in double transgenic mice.</p><p><b>METHODS</b>Two strains of double transgenic mice were used in this experiment, one was integrated with the herpes simplex virus thymidine kinase (HSV-tk) and the enhanced green fluorescence protein (eGFP), the other was with the short hairpin RNA interference(RNAi) and beta(654). Splenic cells cultured in vitro were arrested in metaphase by colchicine and hybridized with digoxigenin-labeled and biotinylated DNA probes, then detected by rhodamine-conjugated avidin and FITC-conjugated anti-digoxigenin.</p><p><b>RESULTS</b>Dual-color fluorescence signals were detected on the same metaphase in both transgenic mice strains. In HSV-tk/eGFP double transgenic mice, strong green fluorescence for HSV-tk and red for eGFP were observed and localized at 2E5-G3 and 8A2-A4 respectively. In beta(654)/RNAi mice, beta(654) was detected as red fluorescence on chromosome 7D3-E2, and RNAi showed random integration on chromosomes. It was detected as green fluorescence on chromosome 12B1 in one mouse, while on 1E2.3-1F and 3A3 in the other.</p><p><b>CONCLUSION</b>Highly sensitive and specific D-FISH method was established using the self-prepared DNA probes, and chromosomal localization of the foreign genes was also performed in combination with G-banding in double transgenic mice. This technology will facilitate the researches in transgenic animals and gene therapy models.</p>

Identification of candidate genes for drought stress tolerance in rice by the integration of a genetic (QTL) map with the rice genome physical map / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Genetic improvement for drought stress tolerance in rice involves the quantitative nature of the trait, which reflects the additive effects of several genetic loci throughout the genome. Yield components and related traits under stressed and well-water conditions were assayed in mapping populations derived from crosses of AzucenaxIR64 and AzucenaxBala. To find the candidate rice genes underlying Quantitative Trait Loci (QTL) in these populations, we conducted in silico analysis of a candidate region flanked by the genetic markers RM212 and RM319 on chromosome 1, proximal to the semi-dwarf (sd1) locus. A total of 175 annotated genes were identified from this region. These included 48 genes annotated by functional homology to known genes, 23 pseudogenes, 24 ab initio predicted genes supported by an alignment match to an EST (Expressed sequence tag) of unknown function, and 80 hypothetical genes predicted solely by ab initio means. Among these, 16 candidate genes could potentially be involved in drought stress response.

Structural and functional analysis of rice genome.

Rice is an excellent system for plant genomics as it represents a modest size genome of 430 Mb. It feeds more than half the population of the world. Draft sequences of the rice genome, derived by whole-genome shotgun approach at relatively low coverage (4-6 X), were published and the International Rice Genome Sequencing Project (IRGSP) declared high quality (>10 X), genetically anchored, phase 2 level sequence in 2002. In addition, phase 3 level finished sequence of chromosomes 1, 4 and 10 (out of 12 chromosomes of rice) has already been reported by scientists from IRGSP consortium. Various estimates of genes in rice place the number at >50,000. Already, over 28,000 full-length cDNAs have been sequenced, most of which map to genetically anchored genome sequence. Such information is very useful in revealing novel features of macro- and micro-level synteny of rice genome with other cereals. Microarray analysis is unraveling the identity of rice genes expressing in temporal and spatial manner and should help target candidate genes useful for improving traits of agronomic importance. Simultaneously, functional analysis of rice genome has been initiated by marker-based characterization of useful genes and employing functional knock-outs created by mutation or gene tagging. Integration of this enormous information is expected to catalyze tremendous activity on basic and applied aspects of rice genomics.

Restriction fragment analysis of the ribosomal DNA of Paratelmatobius and Scythrophrys species (Anura, Leptodactylidae)

Physical maps of the ribosomal RNA gene 28S of species belonging to the genera Paratelmatobius and Scythrophrys were constructed, using five restriction endonucleases. The restriction sites for Bam HI, Bgl II, Bst EII, and Eco RI had similar positions in all species, although there were interspecific differences in the size of the restriction fragments obtained. An additional Pvu II site was found in Scythrophrys specimens from Piraquara (State of Paraná, Brazil) and from Säo Bento do Sul (State of Santa Catarina, Brazil), but not in the Scythrophrys specimens from Rancho Queimado (State of Santa Catarina, Brazil). This finding is in agreement with the hypothesis regarding the existence of two species in the genus Scythrophrys. On the other hand, the extra Bst EII site considered in the literature to be a synapomorphy for the subfamilies Leptodactylinae and Telmatobiinae was not observed in the genera Paratelmatobius and Scythrophrys, which brings new questions about some taxonomic classifications that include Paratelmatobius in Leptodactylinae and Scythrophrys in Telmatobiinae. Interspecific variation was observed in the size of the restriction fragments analyzed and, in the case of group I Scythrophrys, there was also a variation between the individuals of the two populations. These data suggest that sequencing of the rDNA segments studied here may be useful in phylogenetic studies of the genera Paratelmatobius and Scythrophrys

Physical map and one-megabase sequencing of the human immunoglobulin lambda locus

O locus IGL humano está localizado no cromossomo 22q11.1-q11.2 e contém os genes responsáveis pelas cadeias leves de imunoglobulinas tipo lambda. Este locus foi recentemente mapeado (mapa físico) e seu 1 Mb DNA totalmente sequenciado. Neste revisäo focamos os principais resultados de caracterizaçäo dos genes v-lambda, sua localizaçäo cromossômica, a genômica e seqüenciamento do locus IGL.