Table of Contents | Genet. Mol. Res. 2018 (4)
Phosphate (Pi) unavailability is a growth-limiting factor for plants. Under Pi-limited conditions, plants activate molecular mechanisms for better acquisition and utilization of this nutrient. In maize, changes in the expression pattern of several Pi starvation-induced genes, including the A1 coding for dihydroflavonol 4-reductase (DFR) involved in anthocyanin biosynthesis, were identified through microarray analysis. In order to elucidate the molecular determinants with a potential role in P use efficiency, we carried out a study on gene expression analysis of the A1 phosphate responsive gene by northern blot analysis of total RNA from maize genotypes contrasting for Pi efficiency. Two Pi-efficient (L-03 and L-161-1) and five inefficient (L-11, L-16, L-22, L-53, and L-5046) genotypes of maize were grown for 15 days in hydroponic culture in the presence (250 mM Pi) or absence (0 mM Pi) of phosphate. All genotypes showed an increase in anthocyanin accumulation in roots in the absence of Pi (0 mM Pi). The Pi-efficient genotype L-36 and the Pi-inefficient genotypes L-16, L22, and L-5046 showed the highest levels of anthocyanin accumulation. The A1 gene exhibits temporal and spatial expression patterns associated with Pi deficiency. Although there were differences in the expression profile of Pi starvation induced genes, no consistent expression patterns could be associated with either Pi-efficient or Pi-inefficient genotypes. It appears that Pi efficiency in tropical maize is a complex trait mediated by a coordinated action of genes that are either induced or suppressed in response to Pi-deficiency.
Genipa americana (Rubiaceae) is an endemic Amazon-region species that may be subject to inbreeding, since it grows in fragmented environments. To examine this possibility, we examined the genetic diversity and population structure of three G. americana populations naturally grown in Northern Mato Grosso State using SSR markers. Sixty-four individuals were sampled from the three populations: 20 in AFL, 20 in MTP, and 24 in NBD. DNA extraction was performed according to the CTAB method, with modifications. Six SSR primers developed for the species were used. The allele frequency, the observed and expected heterozygosity, polymorphism information content), and the fixation Index were estimated. Molecular variance and principal coordinates analyses were conducted, and the most likely number of groups was inferred using the Structure software to help understand the genetic structure of the populations. The six microsatellite loci used showed 17 alleles, in total, ranging from 2 to 4 alleles per locus, with a mean of 2.83. The expected heterozygosity ranged from 0.35 to 0.67 and remained higher than the observed heterozygosity for all loci. The three populations showed genetic diversity, shared genetic material and presented high inbreeding indexes. Cluster analysis results showed genetic material sharing between populations, as well as a lack of genetic structuring among individuals according to their geographical origins. The molecular characterization revealed that the genetic diversity is higher within than between populations. The three populations had shared genetic material and a high inbreeding index due to low observed heterozygosity. This could be a consequence of the fragmented environment where these populations currently live in, since it reduces the number of G. americana individuals and can increase inbreeding.
We investigated the effects of an allogenic infusion of mesenchymal stem cells derived from adipose tissue for treatment of dogs with neurological sequelae secondary to infection with canine distemper virus. Seven dogs were selected, all of which presented positive PCR for canine distemper and later, after clinical treatment, presented negative PCR but retained at least one post-infection neurological signal. Cell therapy was performed on days 1, 15, and 30; blood samples were taken on days 1 and 30for a hemogram, and the animals were evaluated on days 1, 15, 30, 45, and 180 for walking characteristics, urinary or fecal incontinence, state of consciousness, myoclonus, and occurrence of seizures. A descriptive numerical scale was established for scoring and classifying the various parameters that were evaluated. All the animals demonstrated post-therapy clinical neurological improvement, especially for the parameters walking and urinary and fecal incontinence; this improvement was significant throughout the evaluation period. Allogenic infusion of mesenchymal stem cells derived from adipose tissue in dogs with neurological sequelae secondary to infection by the canine distemper virus proved to be an efficient treatment.
The orchid family Orchidaceae is one of the largest families of angiosperms; it includes approximately 35,000 species, displays a wide range of unique ﬂower shapes and is a valued ornamental crop. Among the various species of orchids, the Phalaenopsis genus is the most widely commercialized among blooming potted plants. Our aim was to provide in-depth sequence information for the various parts of flowers, different time treatments of the protocorm-like bodies and temperature treated shortened stems for flowering pathway regulation, in addition to adding to the available data on normal and peloric mutants. We also obtained transcriptome data from shortened stems under cool temperature for spike induction. The deep sequenced, assembled and annotated information was integrated and built into a database that we named PhalDB. Existing databases, such as OrchidBase, OrchidBase 2.0, Orchidstra, and Orchidstra 2.0 mainly contain information on expressed sequence tags, unigenes, and microRNA only from floral organs of orchid species. These databases do not include information about somaclonal variations and cool temperature treatment, which are important for commercial variety development. PhalDB provides sequence information from 24 samples and covers the above-mentioned tissues or conditions so that comprehensive gene data related to flower development, somaclonal variation and some horticulture traits are available for searching. A user can access DNA level information and miRNA structure, etc. It also provides an opportunity to explore mRNA level information and interactions between genes and miRNA. PhalDB is equipped with a BLAST tool to perform similarity searches among the various gene sequences.
The growing demand for maize creates a challenge for breeders; they need to constantly develop higher yielding and higher quality genotypes. We estimated the most relevant genetic parameters, along with heterosis and variance components. A multivariate approach was used in order to define profiles of narrow sense heritability for yield and nutritional components in half-sibling maize progenies. The applied experimental design was random blocks with a male parent (hybrid tester), five inbred lines (S5) as maternal parents and the progenies (hybrid Top Cross), totaling 11 maize genotypes arranged in six replicates. Agronomic and nutritional characters were evaluated. Half-sibling progenies revealed greater additive genetic contribution to phenotypic expression with grain width and thickness, iron content, total flavonoids and carotenoids, soluble solids, and methionine. Narrow sense heritability values between and within progenies were higher for manganese content, glycine, proline and tryptophan. Regardless of the S5 inbreeding line used, heterosis gains were obtained for ear insertion height, number of grain rows per ear, stalk diameter, zinc content, total carotenoids, soluble solids and pH. Specific heterosis was found for grain yield, glycine, serine, threonine and phenylalanine. The multivariate analysis defined eight profiles of traits according to their genetic tendencies, and indicated narrow sense heritability of the progeny mean as the main reason for this classification.