Several types of sex chromosome systems have been recorded among Gymnotiformes, including male and female heterogamety, simple and multiple sex chromosomes, and different mechanisms of origin and evolution. The X1X1X2X2/X1X2Y systems identified in three species of this order are considered homoplasic for the group. In the genus Brachyhypopomus, only B. gauderio presented this type of system. Herein we describe the karyotypes of Brachyhypopomus pinnicaudatus and B. n. sp. FLAV, which have an X1X1X2X2/X1X2Y sex chromosome system that evolved via fusion between an autosome and the Y chromosome. The morphology of the chromosomes and the meiotic pairing suggest that the sex chromosomes of B. gauderio and B. pinnicaudatus have a common origin, whereas in B . n. sp. FLAV the sex chromosome system evolved independently. However, we cannot discard the possibility of common origin followed by distinct processes of differentiation. The identification of two new karyotypes with an X1X1X2X2/X1X2Y sex chromosome system in Gymnotiformes makes it the most common among the karyotyped species of the group. Comparisons of these karyotypes and the evolutionary history of the taxa indicate independent origins for their sex chromosomes systems. The recurrent emergence of the X1X1X2X2/X1X2Y system may represent sex chromosomes turnover events in Gymnotiformes.
sex chromosome fusion; sexual trivalent; meiosis
Dystrobrevin binding protein 1 (DTNBP1) gene is pivotal in regulating the glutamatergic system. Genetic variants of the DTNBP1 affect cognition and thus may be particularly relevant to schizophrenia. We therefore evaluated the association of six single nucleotide polymorphisms (SNPs) with schizophrenia in a Malaysian population (171 cases; 171 controls). Associations between these six SNPs and schizophrenia were tested in two stages. Association signals with p < 0.05 and minor allele frequency > 0.05 in stage 1 were followed by genotyping the SNPs in a replication phase (stage 2). Genotyping was performed with sequenced specific primer (PCR-SSP) and restriction fragment length polymorphism (PCR-RFLP). In our sample, we found significant associations between rs2619522 (allele p = 0.002, OR = 1.902, 95%CI = 1.266 – 2.859; genotype p = 0.002) and rs2619528 (allele p = 0.008, OR = 1.606, 95%CI = 1.130 – 2.281; genotype p = 6.18 × 10−5) and schizophrenia. Given that these two SNPs may be associated with the pathophysiology of schizophrenia, further studies on the other DTNBP1 variants are warranted.
case-control study; DTNBP1; schizophrenia; single nucleotide polymorphism
Eucalyptus urograndis is a hybrid eucalyptus of major economic importance to the Brazilian pulp and paper industry. Although widely used in forest nurseries around the country, little is known about the biochemical changes imposed by environmental stress in this species. In this study, we evaluated the changes in the stem proteome after short-term stimulation by exposure to low temperature. Using two-dimensional gel electrophoresis coupled to high-resolution mass spectrometry-based protein identification, 12 proteins were found to be differentially regulated and successfully identified after stringent database searches against a protein database from a closely related species (Eucalyptus grandis). The identification of these proteins indicated that the E. urograndis stem proteome responded quickly to low temperature, mostly by down-regulating specific proteins involved in energy metabolism, protein synthesis and signaling. The results of this study represent the first step in understanding the molecular and biochemical responses of E. urograndis to thermal stress.
abiotic stress; mass spectrometry; omics; proteomics
Centronuclear myopathy (CNM) is a rare congenital muscle disease characterized by fibers with prominent centralized nuclei in muscle biopsies. The disease is clinically heterogeneous, ranging from severe neonatal hypotonic phenotypes to adult-onset mild muscle weakness, and can have multiple modes of inheritance in association with various genes, including MTM1, DNM2, BIN1 and RYR1. Here we analyzed 18 sporadic patients with clinical and histological diagnosis of CNM and sequenced the DNM2 gene, which codes for the dynamin 2 protein. We found DNM2 missense mutations in two patients, both in exon 8, one known (p.E368K) and one novel (p.F372C), which is found in a position of presumed pathogenicity and appeared de novo. The patients had similar phenotypes characterized by neonatal signs followed by improvement and late childhood reemergence of slowly progressive generalized muscle weakness, elongated face with ptosis and ophthalmoparesis, and histology showing fibers with radiating sarcoplasmic strands (RSS). These patients were the only ones in the series to present this histological marker, which together with previous reports in the literature suggest that, when RSS are present, direct sequencing of DNM2 mutation hot spot regions should be the first step in the molecular diagnosis of CNM, even in sporadic cases.
centronuclear myopathy; DNM2; dynamin 2; congenital myopathy
This study presents evidence, using sequences of ribosomal 16S and COI mtDNA, for the presence of two mitochondrial genomes in Perumytilus purpuratus. This may be considered evidence of doubly uniparental mtDNA inheritance. The presence of the two types of mitochondrial genomes differentiates females from males. The F genome was found in the somatic and gonadal tissues of females and in the somatic tissues of males; the M genome was found in the gonads and mantle of males only. For the mitochondrial 16S region, ten haplotypes were found for the F genome (nucleotide diversity 0.004), and 7 haplotypes for the M genome (nucleotide diversity 0.001), with a distance Dxy of 0.125 and divergence Kxy of 60.33%. For the COI gene 17 haplotypes were found for the F genome (nucleotide diversity 0.009), and 10 haplotypes for the M genome (nucleotide diversity 0.010), with a genetic distance Dxy of 0.184 and divergence Kxy of 99.97%. Our results report the presence of two well-differentiated, sex-specific types of mitochondrial genome (one present in the male gonad, the other in the female gonad), implying the presence of DUI in P. purpuratus. These results indicate that care must be taken in phylogenetic comparisons using mtDNA sequences of P. purpuratus without considering the sex of the individuals.
Mytilidae; 16S; COI; Perumytilus; DUI
Several single nucleotide polymorphisms (SNPs) in the Mu Opioid Receptor gene (OPRM1) have been identified and associated with a wide variety of clinical phenotypes related both to pain sensitivity and analgesic requirements. The A118G and other potentially functional OPRM1 SNPs show significant differences in their allele distributions among populations. However, they have not been properly addressed in a population genetic analysis. Population stratification could lead to erroneous conclusions when they are not taken into account in association studies. The aim of our study was to analyze OPRM1 SNP variability by comparing population samples of the International Hap Map database and to analyze a new population sample from the city of Corrientes, Argentina. The results confirm that OPRM1 SNP variability differs among human populations and displays a clear ancestry genetic structure, with three population clusters: Africa, Asia, and Europe-America.
OPRM1; SNPs; A118G; AMOVA; population genetics
The aim of this study was to evaluate the impact of different grazing pressures on the activity and diversity of soil bacteria. We performed a long-term experiment in Eldorado do Sul, southern Brazil, that assessed three levels of grazing pressure: high pressure (HP), with 4% herbage allowance (HA), moderate pressure (MP), with 12% HA, and low pressure (LP), with 16% HA. Two reference areas were also assessed, one of never-grazed native vegetation (NG) and another of regenerated vegetation after two years of grazing (RG). Soil samples were evaluated for microbial biomass and enzymatic (β-glucosidase, arylsulfatase and urease) activities. The structure of the bacterial community and the population of diazotrophic bacteria were evaluated by RFLP of the 16S rRNA and nifH genes, respectively. The diversity of diazotrophic bacteria was assessed by partial sequencing of the 16S rDNA gene. The presence of grazing animals increased soil microbial biomass in MP and HP. The structures of the bacterial community and the populations of diazotrophic bacteria were altered by the different grazing managements, with a greater diversity of diazotrophic bacteria in the LP treatment. Based on the characteristics evaluated, the MP treatment was the most appropriate for animal production and conservation of the Pampa biome.
bacterial diversity; diazotrophic bacteria; diversity; grasslands; soil microbial communities
Scinax species are still underrepresented in cytogenetic studies, mainly with respect to populations from northeastern and northern Brazil. In this study, we provide new chromosomal information on Scinax boesemani, S. camposseabrai, S. garbei, S. pachycrus, S. trilineatus and S. x-signatus, all belonging to clade S. ruber. They were collected at two locations in the Caatinga biome (northeastern Brazil) and at one in the Amazon (northern Brazil) biomes. Chromosomes were analyzed by conventional staining, C-banding, Ag-NOR staining, and fluorochrome staining. All species shared a modal diploid value of 2n = 24 and fundamental arm number (FN) of 48. Moreover, both chromosomal size and morphology were similar to other species in this Scinaxclade. C-banding revealed centromeric heterochromatin in all species, along with terminal species-specific C-bands in some species. Active nucleolar organizer regions (Ag-NORs) were identified at 11q in most species, except for S. boesemani and S. garbei (Ag-NORs at interstitial region of 8q). Differing from most anurans, GC-rich regions were not restricted to NORs, but also coincident with some centromeric and terminal C-bands. These data contribute to the cytotaxonomy of Scinax by providing chromosomal markers and demonstrating the occurrence of microstructural rearrangements and inversions on chromosomal evolution of Scinax.
amphibians; chromosomes; fluorochromes; heterochromatin; rDNA
Alstroemeria L., one of the most diverse genera of the Chilean flora and of high floricultural value, is represented by 35 species, most of them distributed between 28–38° S in the Mediterranean zone of Central Chile. There are 24 complex-forming taxa, of which 18 have conservation problems (8 are considered “endangered” and 10 as “vulnerable”). One of these complexes is Alstroemeria presliana Herb. with two subspecies: subsp. presliana and subsp. australis Bayer. Alstroemeria presliana grows in Chile and Argentina: subsp. presliana is distributed from Reserva Nacional Siete Tazas (35°27′ S, Region of Maule) to Antuco, (37°25′ S, Region of Bío-Bío), and is also found in Neuquén, Argentina; subsp. australis is endemic to the Cordillera of Nahuelbuta. A comparative karyotype study was carried out among six populations of A. presliana subsp. presliana and five populations of A. presliana subsp. australis. The eleven populations presented an asymmetric karyotype, with 2n = 2× = 16 chromosomes but with different karyotype formulae. A. presliana subsp. presliana shows the haploid formula 2m + 2m-sat + 1sm-sat + 1st-sat + 1t + 1 t-sat, and A. preslianasubsp. australis presents a formula 1m + 2m-sat + 1sm + 2t + 2t-sat chromosomes. The architecture of the karyotype between the subspecies is very different. The scatter plot among CVCL
vs. MCA shows different groupings between populations of the two subspecies. According to the results obtained it is possible to consider raising Alstroemeria presliana subsp. australis at species level.
Alstroemeria; asymmetry; Chile; karyotype; species complex
Several studies of the physiological responses of different organisms exposed to extremely low-frequency electromagnetic fields (ELF-EMF) have been described. In this work, we report the minimal effects of in situ exposure to ELF-EMF on the global protein expression of Chromobacterium violaceum using a gel-based proteomic approach. The protein expression profile was only slightly altered, with five differentially expressed proteins detected in the exposed cultures; two of these proteins (DNA-binding stress protein, Dps, and alcohol dehydrogenase) were identified by MS/MS. The enhanced expression of Dps possibly helped to prevent physical damage to DNA. Although small, the changes in protein expression observed here were probably beneficial in helping the bacteria to adapt to the stress generated by the electromagnetic field.
C. violaceum; electromagnetic field; proteomic analysis
Increased synthesis of galactinol and raffinose family oligosaccharides (RFOs) has been reported in vegetative tissues in response to a range of abiotic stresses. In this work, we evaluated the transcriptional profile of a Coffea canephora galactinol synthase gene (CcGolS1) in two clones that differed in tolerance to water deficit in order to assess the contribution of this gene to drought tolerance. The expression of CcGolS1 in leaves was differentially regulated by water deficit, depending on the intensity of stress and the genotype. In clone 109A (drought-susceptible), the abundance of CcGolS1 transcripts decreased upon exposure to drought, reaching minimum values during recovery from severe water deficit and stress. In contrast, CcGolS1 gene expression in clone 14 (drought-tolerant) was stimulated by water deficit. Changes in galactinol and RFO content did not correlate with variation in the steady-state transcript level. However, the magnitude of increase in RFO accumulation was higher in the tolerant cultivar, mainly under severe water deficit. The finding that the drought-tolerant coffee clone showed enhanced accumulation of CcGolS1 transcripts and RFOs under water deficit suggests the possibility of using this gene to improve drought tolerance in this important crop.
coffee; drought stress; raffinose family oligosaccharides (RFOs)
Nuclear transfer embryonic stem cells (ntESCs) show stem cell characteristics such as pluripotency but cause no immunological disorders. Although ntESCs are able to differentiate into somatic cells, the ability of ntESCs to differentiate into primordial germ cells (PGCs) has not been examined. In this work, we examined the capacity of mouse ntESCs to differentiate into PGCs in vitro. ntESCs aggregated to form embryoid bodies (EB) in EB culture medium supplemented with bone morphogenetic protein 4(BMP4) as the differentiation factor. The expression level of specific PGC genes was compared at days 4 and 8 using real time PCR. Flow cytometry and immunocytochemical staining were used to detect Mvh as a specific PGC marker. ntESCs expressed particular genes related to different stages of PGC development. Flow cytometry and immunocytochemical staining confirmed the presence of Mvh protein in a small number of cells. There were significant differences between cells that differentiated into PGCs in the group treated with Bmp4 compared to non-treated cells. These findings indicate that ntESCs can differentiate into putative PGCs. Improvement of ntESC differentiation into PGCs may be a reliable means of producing mature germ cells.
differentiation; germ cells; nuclear transfer embryonic stem cells
In this work, we examined the impact of polymorphism in the cytochrome P450 (CYP) 3A5 gene, CYP3A5*1 (6986A > G, rs 776746), on the reduction in the lipid levels caused by simvastatin and atorvastatin. We studied 350 hyperlipidemic patients who received 10-40 mg of atorvastatin (n = 175) or simvastatin (n = 175) daily. Genotyping for CYP3A5 was done by PCR-RFLP analysis. Differences in the lipid profile before and after treatment were expressed as the % difference. The frequency of CYP3A5polymorphism was 13.4% for heterozygotes and 86.6% for homozygotes. Comparison of the responses to same dose of each drug showed that the highest % difference was associated with total cholesterol (TC) in subjects receiving atorvastatin 40 mg compared with simvastatin 40 mg (p = 0.048). However, comparison of the responses to equivalent doses of atorvastatin vs. simvastatin revealed no difference in the % change in any of the lipid parameters examined. In individuals with the same CYP3A5 genotype, a head to head comparison of the efficacy of the same dose of simvastatin vs. atorvastatin revealed an advantage for atorvastatin. For equivalent doses of atorvastatin vs. simvastatin there was no difference in the % change in any of the lipid parameters examined. Within the same genotype there was a significant difference in the % change related to the drug treatment.
atorvastatin; cholesterol; CYP3A5 gene polymorphism; simvastatin
Many phylogenetic questions in the Ciconiiformes remain unresolved and complete mitogenome data are urgently needed for further molecular investigation. In this work, we determined the complete mitogenome sequence of the little egret (Egretta garzetta). The genome was 17,361 bp in length and the gene organization was typical of other avian mtDNA. In protein-coding genes (PCGs), a C insertion was found in ND3, and COIII and ND4 terminated with incomplete stop codons (T). tRNA-Val and tRNA-Ser (AGY) were unable to fold into canonical cloverleaf secondary structures because they had lost the DHU arms. Long repetitive sequences consisting of five types of tandem repeats were found at the 3′ end of Domain III in the control region. A phylogenetic analysis of 11 species of Ciconiiformes was done using complete mitogenome data and 12 PCGs. The tree topologies obtained with these two strategies were identical, which strongly confirmed the monophyly of Ardeidae, Threskiorothidae and Ciconiidae. The phylogenetic analysis also revealed that Egretta was more closely related to Ardea than to Nycticorax in the Ardeidae, and Platalea was more closely related to Threskiornis than to Nipponia in the Threskiornithidae. These findings contribute to our understanding of the phylogenetic relationships of Ciconiiformes based on complete mitogenome data.
Egretta garzetta; mitochondrial genome; phylogenomics
Drosophila mediopunctata has been used as a model organism for
genetics and evolutionary studies in the last three decades. A linkage map with 48
microsatellite loci recently published for this species showed five syntenic groups,
which had their homology determined to Drosophila melanogaster
chromosomes. Then, by inference, each of the groups was associated with one of the
five major chromosomes of D. mediopunctata. Our objective was to
carry out a genetic (chromosomal) analysis to increase the number of available loci
with known chromosomal location. We made a simultaneous analysis of visible mutant
phenotypes and microsatellite genotypes in a backcross of a standard strain and a
mutant strain, which had each major autosome marked. Hence, we could establish the
chromosomal location of seventeen loci; including one from each of the five major
linkage groups previously published, and twelve new loci. Our results were congruent
with the previous location and they open new possibilities to future work integrating
microsatellites, chromosomal inversions, and genetic determinants of physiological
and morphological variation.
tripunctata; SSR; genetic chromosomal analysis; BLAST search; Muller’s elements
Cerebrotendinous Xanthomatosis (CTX), a rare lipid storage disorder, is caused by
recessive loss-of-function mutations of the 27-sterol hydroxylase
(CYP27A1), producing an alteration of the synthesis of bile
acids, with an accumulation of cholestanol. Clinical characteristics include juvenile
cataracts, diarrhea, tendon xanthomas, cognitive impairment and other neurological
manifestations. Early diagnosis is critical, because treatment with chenodeoxycholic
acid may prevent neurological damage. We studied the CYP27A1 gene in
two Chilean CTX patients by sequencing its nine exons, exon-intron boundaries, and
cDNA from peripheral blood mononuclear cells. Patient 1 is a compound heterozygote
for the novel substitution c.256-1G > T that causes exon 2 skipping, leading to a
premature stop codon in exon 3, and for the previously-known pathogenic mutation
c.1183C > T (p.Arg395Cys). Patient 2 is homozygous for the novel mutation
c.1185-1G > A that causes exon 7 skipping and the generation of a premature stop
codon in exon 8, leading to the loss of the crucial adrenoxin binding domain of
Cerebrotendinous Xanthomatosis; splicing; mutation; exon skipping
Peach palm (Bactris gasipaes) is cultivated by many indigenous and
traditional communities from Amazonia to Central America for its edible fruits, and
is currently important for its heart-of-palm. The objective of this study was to
investigate the mating system of peach palm, as this is important for conservation
and breeding. Eight microsatellite loci were used to genotype 24 open-pollinated
progenies from three populations of the Pampa Hermosa landrace maintained in a
progeny trial for genetic improvement. Both the multi-locus outcrossing rates (0.95
to 0.99) and the progeny level multi-locus outcrossing rates (0.9 to 1.0) were high,
indicating that peach palm is predominantly allogamous. The outcrossing rates among
relatives were significantly different from zero (0.101 to 0.202), providing evidence
for considerable biparental inbreeding within populations, probably due to farmers
planting seeds of a small number of open-pollinated progenies in the same plot. The
correlations of paternity estimates were low (0.051 to 0.112), suggesting a large
number of pollen sources (9 to 20) participating in pollination of individual fruit
bunches. Effective population size estimates suggest that current germplasm
collections are insufficient for long-term ex situ conservation. As
with most underutilized crops, on farm conservation is the most important component
of an integrated conservation strategy.
Bactris gasipaes; bi-parental inbreeding; genetic improvement; genetic conservation; outcrossing
In this study, we genetically characterized the Uruguayan pig breed Pampa Rocha.
Genetic variability was assessed by analyzing a panel of 25 microsatellite markers
from a sample of 39 individuals. Pampa Rocha pigs showed high genetic variability
with observed and expected heterozygosities of 0.583 and 0.603, respectively. The
mean number of alleles was 5.72. Twenty-four markers were polymorphic, with 95.8% of
them in Hardy Weinberg equilibrium. The level of endogamy was low (FIS =
0.0475). A factorial analysis of correspondence was used to assess the genetic
differences between Pampa Rocha and other pig breeds; genetic distances were
calculated, and a tree was designed to reflect the distance matrix. Individuals were
also allocated into clusters. This analysis showed that the Pampa Rocha breed was
separated from the other breeds along the first and second axes. The
neighbour-joining tree generated by the genetic distances DA showed
clustering of Pampa Rocha with the Meishan breed. The allocation of individuals to
clusters showed a clear separation of Pampa Rocha pigs. These results provide
insights into the genetic variability of Pampa Rocha pigs and indicate that this
breed is a well-defined genetic entity.
genetic resources; microsatellites
Ectrodactyly – ectodermal dysplasia and cleft lip/palate (EEC) syndrome (OMIM 604292)
is a rare disorder determined by mutations in the TP63 gene. Most
cases of EEC syndrome are associated to mutations in the DNA binding domain (DBD)
region of the p63 protein. Here we report on a three-generation Brazilian family with
three individuals (mother, son and grandfather) affected by EEC syndrome, determined
by a novel mutation c.1037C > G (p.Ala346Gly). The disorder in this family
exhibits a broad spectrum of phenotypes: two individuals were personally examined,
one presenting the complete constellation of EEC syndrome manifestations and the
other presenting an intermediate phenotype; the third affected, a deceased individual
not examined personally and referred to by his daughter, exhibited only the
split-hand/foot malformation (SHFM). Our findings contribute to elucidate the complex
phenotype-genotype correlations in EEC syndrome and other related
TP63-mutation syndromes. The possibility of the mutation c.1037C
> G being related both to acro-dermato-ungual-lacrimal-tooth (ADULT) syndrome and
SHFM is also raised by the findings here reported.
EEC syndrome; TP63-mutations; p63-associated disorders; SHFM
Jatropha gossypiifolia L. (Euphorbiaceae), popularly known as
cotton-leaf physicnut, is a milky shrub notable for its medicinal properties. The
present study aimed to evaluate the toxic, cytotoxic and genotoxic effects of the
latex of J. gossypiifolia, using Allium cepa L. as
test system. Seeds of A. cepa were exposed to five concentrations of
the latex (1.25; 2.5; 5; 10 and 20 mL/L) in order to evaluate parameters of toxicity
(evaluation of root growth), cytotoxicity (mitotic index frequency) and genotoxicity
(frequency of chromosome alterations). The latex showed a significant decrease in
root mean growth value as well as mitotic index for the tested concentrations, except
for 1.25 mL/L, when compared to results from the negative control. The 1.25, 2.5 and
5 mL/L concentrations induced significant chromo-some adherences, C-metaphases and/or
chromosome bridges, as genotoxic effects. The significant frequency of chromosome
bridges also indicated mutagenic potential for chromosomes of J.
gossypiifolia as discussed in the paper. Considering that the latex is
used in popular therapies, and that the test system A. cepa presents
good correlation with tests carried out in mammals, it can be pointed out that its
use for medicinal purposes may be harmful to human health especially if ingested.
Allium cepa test; medicinal plant; plant latex; genotoxicity evaluation
Osteogenesis imperfecta (OI) is a family of genetic disorders associated with bone
loss and fragility. Mutations associated with OI have been found in genes encoding
the type I collagen chains. People with OI type I often produce insufficient α1-chain
type I collagen because of frameshift, nonsense, or splice site mutations in
COL1A1 or COL1A2. This report is of a Chinese
daughter and mother who had both experienced two bone fractures. Because skeletal
fragility is predominantly inherited, we focused on identifying mutations in
COL1A1 and COL1A2 genes. A novel mutation in
COL1A1, c.700delG, was detected by genomic DNA sequencing in the
mother and daughter, but not in their relatives. The identification of this mutation
led to the conclusion that they were affected by mild OI type I. Open reading frame
analysis indicated that this frameshift mutation would truncate α1-chain type I
collagen at residue p263 (p.E234KfsX264), while the wild-type protein would contain
1,464 residues. The clinical data were consistent with the patients’ diagnosis of
mild OI type I caused by haploinsufficiency of α1-chain type I collagen. Combined
with previous reports, identification of the novel mutation
COL1A1-c.700delG in these patients suggests that
additional genetic and environmental factors may influence the severity of OI.
Osteogenesis imperfecta; Chinese OI type 1 family; type I collagen; sequence analysis; frameshift mutation
The WUSCHEL (WUS)-related homeobox (WOX) gene family coordinates transcription during
the early phases of embryogenesis. In this study, a putative WOX2
homolog was isolated and characterized from Aegilops tauschii, the
donor of D genome of Triticum aestivum. The sequence consisted of
2045 bp, and contained an open reading frame (ORF), encoded 322 amino acids. The
predicted protein sequence contained a highly conserved homeodomain and the WUS-box
domain, which is present in some members of the WOX protein family. The full-length
ORF was subcloned into prokaryotic expression vector pET-30a, and an approximately
34-kDa protein was expressed in Escherichia coli BL21 (DE3) cells
with IPTG induction. The molecular mass of the expressed protein was identical to
that predicted by the cDNA sequence. Phylogenetic analysis suggested that Ae.
tauschii WOX2 is closely related to the rice and maize orthologs.
Quantitative PCR analysis showed that WOX2 from Ae.
tauschii was primarily expressed in the seeds; transcription increased
during seed development and declined after the embryos matured, suggesting that
WOX2 is associated with embryo development in Ae.
WOX2; Aegilops tauschii; phylogenetic analysis; real-time quantitative PCR
Campomelic dysplasia (CD) is an autosomal, dominantly inherited, skeletal abnormality
belonging to the subgroup of bent bone dysplasias. In addition to bowed lower limbs,
CD typically includes the following: disproportionate short stature, flat face,
micrognathia, cleft palate, bell-shaped thorax, and club feet. Up to three quarters
of 46, XY individuals may be sex-reversed. Radiological signs include scapular and
pubic hypoplasia, narrow iliac wings, spaced ischia, and bowed femora and tibiae.
Lethal CD is usually due to heterozygous mutations in SOX9, a major regulator of
chondrocytic development. We present a detailed clinical and molecular
characterization of nine Brazilian CD patients. Infants were either stillborn (n = 2)
or died shortly after birth and presented similar phenotypes. Sex-reversal was
observed in one of three chromosomally male patients. Sequencing of SOX9 revealed new
heterozygous mutations in seven individuals. Six patients had mutations that resulted
in premature transcriptional termination, while one infant had a single-nucleotide
substitution at the conserved splice-site acceptor of intron 1. No clear
genotype-phenotype correlations were observed. This study highlights the diversity of
SOX9 mutations leading to lethal CD, and expands the group of known genetic
alterations associated with this skeletal dysplasia.
campomelic dysplasia; skeletal dysplasia; osteochondrodysplasias; SOX9; prenatal diagnosis
Because of the continuous introduction of germplasm from abroad, some collections
have a high number of accessions, making it difficult to explore the genetic
variability present in a germplasm bank for conservation and breeding purposes.
Therefore, the aim of this study was to quantify and analyze the structure of genetic
variability among 500 common bean accessions to construct a core collection. A total
of 58 SSRs were used for this purpose. The polymorphism information content (PIC) in
the 180 common bean accessions selected to compose the core collection ranged from
0.17 to 0.86, and the discriminatory power (DP) ranged from 0.21 to 0.90. The 500
accessions were clustered into 15 distinct groups and the 180 accessions into four
distinct groups in the Structure analysis. According to analysis of molecular
variance, the most divergent accessions comprised 97.2% of the observed genetic
variability present within the base collection, confirming the efficiency of the
selection criterion. The 180 selected accessions will be used for association mapping
in future studies and could be potentially used by breeders to direct new crosses and
generate elite cultivars that meet current and future global market needs.
molecular markers; genetic diversity; genetic structure; microsatellites; Phaseolus vulgaris L
The entomopathogenic fungi of the genus Metarhizium have several
subtilisin-like proteases that are involved in pathogenesis and these have been used
to investigate genes that are differentially expressed in response to different
growth conditions. The identification and characterization of these proteases can
provide insight into how the fungus is capable of infecting a wide variety of insects
and adapt to different substrates. In addition, the pr1A gene has
been used for the genetic improvement of strains used in pest control. In this study
we used quantitative RT-PCR to assess the relative expression levels of the
pr1A gene in M. anisopliae and M.
acridum during growth in different culture conditions and during
infection of the sugar cane borer, Diatraea saccharalis Fabricius.
We also carried out a pathogenicity test to assess the virulence of both species
against D. saccharalis and correlated the results with the pattern
of pr1A gene expression. This analysis revealed that, in both
species, the pr1A gene was differentially expressed under the growth
conditions studied and during the pathogenic process. M. anisopliae
showed higher expression of pr1A in all conditions examined, when
compared to M. acridum. Furthermore, M. anisopliae
showed a greater potential to control D. saccharalis. Taken
together, our results suggest that these species have developed different strategies
to adapt to different growing conditions.
entomopathogen; Diatraea saccharalis; quantitative RT-PCR; expression pattern