ABSTRACT. The degree of genetic divergence was estimated in seven wheat genotypes, six exotic genotypes and one local variety, through random amplified polymorphic DNA methodology. A total of 112 DNA fragments were generated by the 15 random primers, with an average of about 7.4 bands per primer. Among the 112, 50 fragments showed polymorphism among the seven wheat genotypes. Nei and Li’s similarity matrix ranged from 86.2 to 93.0%, which indicated a narrow genetic base among the genotypes. The maximum similarity, 93.0%, was observed between 12WLRG/1-12 and WL-43. The local variety, Chenab-70, showed the lowest similarity with the exotic types. We conclude that random amplified polymorphic DNA analysis can be used for the characterization and grouping of wheat genotypes; these results will be helpful in our wheat breeding program.

ABSTRACT. (Co)variance components and genetic parameters were estimated for body weights of a Romosinuano herd located in Sinú Valley, Cordoba, Colombia. Restricted maximum likelihood methods were used with a univariate animal model for birth weight, weaning weight (270 days), 16-month weight (480 days), weaning daily gain, and post-weaning daily gain. Models included random animal direct and maternal genetic effects, maternal permanent environmental effect (c2), and sex-year-month of birth and age of dam, as fixed effects. Estimates of direct effect for birth weight, weaning weight, 480-day weight, weaning daily gain, and post-weaning daily gain were: 0.25 ± 0.0001, 0.34 ± 0.063, 0.33 ± 0.066, 0.32 ± 0.062, and 0.17 ± 0.052, respectively. Estimates of direct maternal genetic effects were low and ranged from 0.06 ± 0.003 for birth weight to 0.20 ± 0.054 for weaning daily gain. The genetic correlations between direct and maternal genetic effects were negative and low for 480-day weight (-0.05 ± 0.219) and showed values of -0.37 ± 0.007, -0.34 ± 0.133, -0.33 ± 0.135, and -0.38 ± 0.232 for birth, weaning weight, weaning, and post-weaning daily gain, respectively. Permanent environmental maternal effects were not significant; the highest values were found for weaning weight, and weaning daily gain (0.086 ± 0.031 and 0.078 ± 0.031, respectively). We conclude that direct and maternal effects should be included in a selection program for all of these traits, and also that selection of weaning weights would be the most productive way to improve performance in Romosinuano cattle.

ABSTRACT. Fourier transform-infrared photoacoustic spectroscopy was applied for the first time, to our knowledge, to distinguish different castes of an ant species. The method was applied directly to the abdomen of queens, workers and males of Ectatomma vizottoi ants, without any special sample preparation. The absorption bands of secondary amide and hydrocarbons were identified; using these as variables in a canonical discriminant analysis we found significant differences between the castes. Queens have a greater hydrocarbon content than do workers and males, which is related to their function in the colony. This technique can be used to analyze and distinguish small chemical differences in biological systems, even in opaque samples.

ABSTRACT. We developed a procedure for DNA extraction from small volumes of fixed cell suspensions previously prepared for conventional cytogenetic analysis. Good quality DNA was isolated with a fast and simple protocol using DNAzol reagent. This provided suitable DNA for various types of molecular analyses, including polymerase chain reaction, restriction fragment length polymorphism, denaturing high-performance liquid chromatography, and direct sequencing. This technique provides sufficient material for such test, which are important for diagnosis of neoplastic diseases in pediatric patients.

ABSTRACT. Four populations of Serrapinnus notomelas and one population of Serrapinnus sp.1, both belonging to the subfamily Cheirodontinae, were analyzed by Giemsa and silver nitrate impregnation techniques. We found 2n = 52 chromosomes for all populations, with interspecific differences in the karyotype formula; S. notomelas showed 16m + 22sm + 10st + 4a, with fundamental number (FN) = 100 for males, and 16m + 23sm + 10st + 3a, with FN = 101 for females. Serrapinnus sp.1 had 8m + 16sm + 4st + 24a, with FN = 80 for males, and 8m + 15sm + 4st + 25a, with FN = 79 for females. The difference in FN for the two sexes is due to a pair of heteromorphic chromosomes in the females of both species, which characterizes a ZZ/ZW-type mechanism of chromosome sexual determination. Interspecies differences were also found in nucleolus organizer regions (NORs). A simple NOR system was detected in three of four S. notomelas populations, while Serrapinnus sp.1 had two chromosome pairs with NOR. Although S. notomelas and Serrapinnus sp.1 have the same diploid number, differences in the karyotype structure indicate that these are different species. Apparently there was pericentric inversion during the karyotype evolution of these species.

ABSTRACT. A freshwater enterobacterial population (N = 111) was studied for antimicrobial and mercury resistance patterns, and for its possible association with biotic and abiotic factors in that environment. Conventional biochemical tests identified Klebsiella sp, Morganella sp, Serratia sp, Escherichia sp, Enterobacter sp, Edwarsiella sp, Proteus sp, Citrobacter sp, Providencia sp, and Kluyvera sp. There was no correlation between antimicrobial resistance patterns of isolates and bacterial genera, but resistance patterns varied among water samples and between seasons. Resistance to multiple antimicrobials was common (61%). The percentage of bacteria resistant to at least one antimicrobial differed between the rainy (100%) and dry seasons (89%). Resistance to β-lactams and chloramphenicol was the most frequent and resistance to amikacin, gentamicin and kanamycin was less frequent. The main water variables examined (abiotic factors pH and temperature; biotic factor chlorophyll a concentration) did not influence antimicrobial resistance. Significant impact on freshwater enterobacteria, as evidenced by antimicrobial-multiple resistance and by the presence of bla_TEM gene, may point to the fact that it has an important role in horizontal spread of resistance.

ABSTRACT. The evolutionary tree reconstruction algorithm called SEMPHY using structural expectation maximization (SEM) is an efficient approach but has local optimality problem. To improve SEMPHY, a new algorithm named HSEMPHY based on the homotopy continuation principle is proposed in the present study for reconstructing evolutionary trees. The HSEMPHY algorithm computes the condition probability of hidden variables in the structural through maximum entropy principle. It can reduce the influence of the initial value of the final resolution by simulating the process of the homotopy principle and by introducing the homotopy parameter β. HSEMPHY is tested on real datasets and simulated dataset to compare with SEMPHY and the two most popular reconstruction approaches PHYML and RAXML. Experimental results show that HSEMPHY is at least as good as PHYML and RAXML and is very robust to poor starting trees.

ABSTRACT. Vitamin D has important immuno-modulatory properties and it influences insulin secretion. It acts through a vitamin D receptor (VDR), for which several gene polymorphisms have been described. The Uruguayan population presents several epidemiological characteristics that make it different from that of other counties, including other Latin-American countries. It went through miscegenation processes, with a tri-hybrid European, Amerindian and African origin, with no contribution from isolated Amerindian communities. Such differences have important consequences for the relationship between frequencies of several genes in the general population and their association with the diabetes mellitus. We examined the prevalence of VDR gene polymorphisms in the general population and their relation to type 1 diabetes in a parent-case design. One hundred unrelated individuals from the general population and 45 parent-patient triads with a child affected with type 1 diabetes were genotyped for FokI, BsmI and TaqI VDR gene polymorphisms by RFLP-PCR. We used a transmission disequilibrium test to assess preferential transmission of parents to affected offspring. The prevalence of the three VDR polymorphisms was: allele F = 48%, B = 35%, T = 64%. The f, b, T alleles and heterozygous genotypes were found at a high frequency in this population. Among 36 informative heterozygous parental genotypes, 30 transmitted the F allele (probability of transmission = 83%). The other two polymorphisms did not show significant transmission. We suggest that FokI polymorphism indicates susceptibility to type 1 diabetes mellitus in the Uruguayan population.

ABSTRACT. Dalbergia nigra (rosewood) is a long-lived leguminous species, which is endemic to the Brazilian Atlantic forest. Because of the high economic value of its wood, this species has been over-explored in recent years. Currently, rosewood is included in the IUCN Red List as vulnerable. We examined the genetic diversity of 87 specimens of D. nigra sampled from a continuous forest in the Veracel Reserve and Brazilwood Ecological Station, Porto Seguro, Bahia state, with random amplified polymorphic DNA markers. Grouping analyses were done using unweighted pair group method with arithmetic averages. Using the 16 most informative primers, 112 markers were obtained; 39% (44 bands) were polymorphic. A genetic similarity matrix was made based on the polymorphic bands. The dispersion graph and dendrogram analyses showed three distinct sub-populations. The degree of polymorphism was high, near that of other populations of similar species; however, it was considered low for the conservation of this species.

ABSTRACT. Apoptosis has an essential function in maintaining the integrity of the gastrointestinal mucosa. Its deregulation is associated with the occurrence of lesions such as in atrophic gastritis, peptic ulcers, intestinal metaplasia, and stomach tumorigenesis. Thus, the aim of the present study was to investigate the frequency of apoptotic cells (apoptotic index, AI) by using two different immunohistochemical techniques, TUNEL and anti-activated caspase-3 antibody (CPP32), in gastric dyspepsia [chronic gastritis (CG, N = 34), chronic atrophic gastritis (CAG, N = 11), gastric ulcer (GU, N = 17), and intestinal metaplasia (IM, N = 15)], normal gastric mucosae (NM, N = 8), and gastric adenocarcinoma (GC, N = 12). The relationship was investigated between the AI and Helicobacter pylori infection, diagnosed by PCR, overexpression of p53 protein determined by immunohistochemistry, and aneuploidy by fluorescence in situ hybridization, as performed by our laboratory in previous studies. No significant differences were observed in AI between the different groups, whether by the TUNEL technique (F = 1.60; p = 0.1670) or by CPP32 antibody (F = 1.70; p = 0.1420). Nonetheless, CAG and CG groups had AI statistically higher than those of normal mucosae. These two groups (CAG and CG) also showed a higher frequency of apoptosis-positive cases (TUNEL+ or CPP32+). Generally, there was no correlation between the AI detected by the TUNEL and CPP32 techniques in the groups studied, except in the GC group (r = 0.70). Moreover, there was no significant association between apoptosis and H. pylori infection, overexpression of p53 protein and aneuploidy, but the H. pylori-positive cases only of GU (p = 0.0233) and IM (p = 0.0253) groups displayed a statistically higher AI compared to H. pylori-negative NM, when the CPP32 antibody technique was used. Thus, CG and CAG have increased apoptosis, which may occur independent of an association with H. pylori infection, aneuploidy and overexpression of p53 protein.

ABSTRACT. To ascertain whether used and re-refined lubricant oil absorbed through the skin can produce a genotoxic effect or cytotoxicity in mouse bone marrow cells, we examined the induction of micronucleated erythrocytes of peripheral blood after cutaneous application. Both re-refined and used lubricant oils showed a weak but significant induction of micronucleated polychromatic erythrocytes compared with control, while virgin oil did not show micronucleus induction. Cyclophosphamide (CP) was used not only as positive control but also to compare the sensitivity between intraperitoneal and dermal routes of administration of the test compounds in mice. The efficacy of intraperitoneal injection of CP is well known. On the other hand, dermal exposure is not so common and when CP was diluted in glycerin statistically significant values (P = 0.0036) of micronuclei were also found. Topically applied lubricant oils (virgin, re-refined and used) have the capacity to interfere with mouse bone marrow hematopoiesis evidenced by a statistically significant decrease in the proportion of polychromatic erythrocytes in the peripheral blood. Physical and chemical analysis revealed that used oil is more viscous than other lubricants, suggesting the presence of insoluble compounds, oxidized products and water as well as aromatic hydrocarbons. Used oil differs from other lubricant oils in metal and polyaromatic hydrocarbon content. Re-refined oil revealed a neutral value typical of pure mineral oil. This assay is an important tool to evaluate environmental pollutants that cause genotoxicity and/or cytotoxicity through skin exposure.

ABSTRACT. The parrotfishes (family Scaridae) are comprised of the subfamilies Sparisomatinae and Scarinae. They are important agents of marine bioerosion, which rework the substrate with their beaklike jaws. Despite their importance, there are no published cytogenetic data on this group. We made cytogenetic analyses of Sparisoma axillare (Sparisomatinae) and Scarus coelestinus (Scarinae) from the Brazilian coast. Differentiation in the diploid number in S. axillare compared to the basal karyotype of the Perciformes apparently occurred due to a Robertsonian fusion, combined with pericentric inversions. S. coelestinus presented a conserved diploid number, but showed considerable structural karyotypic changes, resulting mainly from pericentric inversions. The Ag-NOR sites were unique and located on the short arm of the 1st subtelocentric pair in both species (possibly homeologous), corresponding to the 11th pair in S. axillare and the 9th pair in S. coelestinus. The constitutive heterochromatin is reduced in these species and is distributed in centromeric and pericentromeric regions in most of the chromosomes. The low fundamental number compared to the Scarus genus suggests a more basal condition for Sparisoma. The chromosome formula in S. coelestinus was more diversified, deriving from large-scale pericentric inversions. Karyotypic evolution patterns observed for these representatives of the Sparisomatinae and Scarinae subfamilies, added to new data from a larger number of species, would allow us to determine if there is a tendency among the Sparisomatinae for centric fusion events.

ABSTRACT. Sanitation workers handling pesticides in the control of disease vectors constitute an occupationally exposed population to genotoxic substances. The aim of the present study was to investigate the relation between the occupational exposure to various pesticides and the presence of cytogenetic damage. Fifty-nine men were selected (29 sanitation workers and 30 control individuals) with ages varying between 18-57 years who lived and worked in the same area in Belo Horizonte (Brazil). The following parameters were determined for all individuals using the cytokinesis-block micronucleus (MN) assay in peripheral blood lymphocytes: MN/1000 binucleated cells (BC), BC with MN (BCMN)/1000 BC, nucleoplasmic bridges (NB)/1000 BC, apoptotic and necrotic cells/500 cells and nuclear division index. The analysis of covariance showed significantly higher (p < 0.05) mean frequencies of MN (15.81 ± 1.31 vs 4.71 ± 0.42), BCMN (15.10 ± 1.22 vs 4.62 ± 0.44), NB (4.59 ± 0.76 vs 1.00 ± 0.34), and necrotic cells (12.07 ± 1.45 vs 5.17 ± 0.70) in the exposed group when compared to the control group. There was no significant difference in the apoptotic cell frequency between the two groups, while the nuclear division index was significantly lower (1.49 ± 0.02 vs 1.61 ± 0.02) in the control group. Neither the time of exposure nor the smoking or alcohol drinking habit influenced the cytogenetic parameters examined. According to these results, occupational exposure to pesticides induced genotoxic and cytotoxic effects in sanitation workers.

ABSTRACT. A review of previous studies is presented on estimates of genetic parameters and responses to selection with traditional breeding approaches, on correlations between agonistic behavior and growth performance, and on theoretical frameworks for selection incorporating interactions among individuals and on practical methods for incorporating competition effects in breeding programs.

ABSTRACT. We examined the capacity of strains of Glomerella cin-gulata f. sp phaseoli fungus (Colletotrichum lindemuthianum sexual stage) to form recombinants, using random amplified polymorphic DNA (RAPD). Crosses of all possible combinations between strains 40, 42, 20, 21, 22, 23, 24, 25, and 26 were made on Petri dishes using M3 culture medium. The 42 x 21 cross produced the largest number of perithecia and five asci; the respective ascospores were isolated. RAPD analysis was performed on the parents and descendants. The 62 polymorphic RAPD bands obtained were used to assess the genetic similarity using the method of Sorence and Dice and clustering analysis in the form of a dendrogram by the UPGMA method. The RAPD markers allowed identification of recombinants from the cross between strains 42 and 21 of G. cingulata f. sp phaseoli and 40 ascospores presented 63 and 49% genetic similarity with parents 2 (strain 42) and 1 (strain 21), respectively.

ABSTRACT. Microsporogenesis was evaluated in the Brachiaria humidicola collection of the Embrapa Beef Cattle Center, represented by 60 accessions. One accession (H121) presented an abnormal pattern of cytokinesis that had never been reported in this genus. Among 900 meiocytes analyzed in the first division, 10.7% underwent precocious and multiple cytokinesis in metaphase I, fractionating the genome and the cytoplasm into two or more parts. The expected cytokinesis after telophase I did not occur. The abnormal meiocytes from the first division entered the second division but the second cytokinesis after telophase II was also abnormal. Among the 857 meiocytes analyzed in the second division, 10.9% presented abnormal, incomplete or total absence of cytokinesis. Dyads and binucleated microspores were recorded among the meiotic products. The use of this accession in the Embrapa breeding program is compromised.

ABSTRACT. Nijmegen breakage syndrome (NBS) is a rare auto-somal recessive condition with chromosomal instability. Clinical and biological overlap between Fanconi anemia and ataxia telangiectasia has been reported. We report two cases of NBS born to consanguineous parents. Case one had NBS and Falconi anemia clinical features but relatively little chromosome breakage. The second case had mild NBS features, while cytogenetic evaluation with mitomycin C induction showed chromosome damage. Chromosomal analysis of bone marrow cells revealed tetraploidy, which indicates progression towards leukemia. On the basis of clinical and cytogenetic evaluation, these two cases were confirmed as NBS. However, detailed molecular studies are essential for accurate diagnosis and management of this disease.

ABSTRACT. We made a cytogenetic study of the fish Rhamdia quelen collected from the Bodoquena Plateau, an isolated national park region in Mato Grosso do Sul State, Brazil. The diploid number was 2n = 58, with 36 metacentric + 16 submetacentric + 6 subtelocentric chromosomes. We found one to three B chromosomes, which were metacentric and submetacentric and of medium size, showing both intra- and interindividual variation. The nucleolus organizer region (NOR) was located in the terminal region of the short arm of submetacentric pair 20. Staining with CMA₃ fluorochrome revealed the NOR location, while there was no evidence of fluorescent staining with DAPI. C banding revealed heterochromatin mainly in the terminal regions of the chromosome arms, including the NOR pair. In addition, metacentric pair 2 showed three heterochromatic blocks in the terminal portions and in the pericentromeric region. The B chromosomes appeared euchromatic. The CB + CMA₃ staining combination demonstrated only one chromosome pair with fluorescence, probably the NOR-bearing one, while CB + DAPI gave various fluorescent signals, including metacentric pair 2, indicating that these heterochromatic regions are AT-rich in this population of R. quelen. The R. quelen population in this isolated region of Brazil is chromosomally distinct from that of other populations that have been studied.

ABSTRACT. The heterokaryotic and vegetative diploid phases of Colletotrichum lindemuthianum are described using nutritional and biochemical markers. Nitrate non-utilizing mutants (nit), derived from R2047, R89, R73, R65, and R23 isolates, were paired in all possible combinations to obtain heterokaryons. Although pairings R2047/R89, R2047/R73, R65/R73, and R73/R23 showed complete vegetative incompatibility, prototrophic heterokaryons were obtained from pairings R2047/R65, R2047/R23, R65/R89, R65/R23, R73/R89, R89/R23, R2047/R2047, R65/R65, R89/R89, R73/R73, and R23/R23. Heterokaryons gave rise to spontaneous mitotic segregants which carried markers corresponding to one or the other of the parental strains. Heterokaryons spontaneously produced prototrophic fast-growing sectors too, characterized as diploid segregants. Diploids would be expected to yield auxotrophic segregants following haploidization in basal medium or in the presence of benomyl. Parental haploid segregants were in fact recovered from diploid colonies growing in basal medium and basal medium containing the haploidizing agent. Although barriers to the formation of heterokaryons in some crosses were detected, the results demonstrate the occurrence of parasexuality among vegetative compatible mutants of C. lindemuthianum.

ABSTRACT. There have been many studies on Schistocerca gregaria and Locusta migratoria, which are important grasshopper pests in many parts of the world. However, the main pest grasshopper species in Brazil, S. pallens, Rhammatocerus schistocercoides and Stiphra robusta, are very poorly characterized genetically. We adapted a permanent in situ hybridization method to extend the genetic characterization of S. pallens by mapping the single-copy genes Hsp70, Hsp83, Hsp27, and Ubi on meiotic chromosomes. Hsp70 was mapped on the L₂ chromosome, in which 82% of the signals were observed. Hsp83 was mapped on a medium-sized chromosome, on which 81% of the signals were observed, tentatively identified as M₇. The hybridization signals for the Hsp27 gene were detected on the L₁ chromosome at a frequency of 58%. The main hybridization site of the Ubi probe was on the L₂ chromosome, with 73% of the signals. All mapped genes also presented secondary hybridization signals, always at frequencies below 30%. These are the first single-copy genes mapped for S. pallens and also for the Acrididae family. Since the Acrididae generally present very similar karyotypes, these data are useful as new landmarks for chromosome identification and as a tool for phylogenetic studies on the genus Schistocerca and for comparison with other insects.

ABSTRACT. Three populations of the genus Crenicichla, namely Crenicichla iguassuensis, Crenicichla sp 1 and Crenicichla sp 2, from the Iguaçu River, were analyzed cytogenetically, and their nucleolus organizer regions, constitutive heterochromatin distribution and chromomycin A₃ markings were studied. Karyotype analyses showed a diploid number of 48 chromosomes, made up of 2 metacentric pairs, 2 submetacentric pairs, 7 subtelocentric pairs, and 13 acrocentric pairs for the three Crenicichla species and no sexual chromosome differentiation. Nucleolus organizer regions showed strong interstitial marking on the first chromosome pair, coincident with a constriction presented by Giemsa and positive marking by chromomycin. Although constitutive heterochromatin patterns were also similar, with pericentromeric markings, small differences in the three species could be observed. Crenicichla sp 2 presented some chromosomes with bitelomeric markings absent in Crenicichla iguassuensis and Crenicichla sp 1.

ABSTRACT. DNA extraction protocols are as varied as DNA sources. When it comes to endangered species, it is especially important to pay attention to all details that ensure the completion of the study goals and effectiveness in attaining useful data for conservation. Chaetomys subspinosus (Rodentia: Erethizontidae) is a secretive arboreal porcupine endemic to certain ecosystems of the Brazilian Atlantic Forest. A multidisciplinary study (including genetic data) was performed to create a management plan for the conservation of this species. Individuals from natural populations of the states of Bahia, Espírito Santo and Sergipe were sampled. To obtain a reliable and abundant amount of starting material, non-destructive methods were tested, extracting DNA from the bristles and quills that comprise most of this animal’s hide. This method has also been innovative in adapting a DNA extraction protocol traditionally used for plants. Digestion using proteinase K was followed by protein precipitation with CTAB, a chloroform-isoamyl alcohol cleaning and DNA precipitation with isopropyl alcohol. This protocol supplies good-quality DNA for genetic analysis with molecular markers based on PCR.

ABSTRACT. Mucopolysaccharidoses are a group of inherited metabolic diseases caused by the absence or deficiency of the lysosomal enzymes that are needed for breaking down glycosaminoglycans (GAGs). Over time, GAGs collect in cells, blood and connective tissues, and increased amounts are excreted in the urine. The result is permanent and includes progressive cell damage that affects the individual’s appearance, physical abilities, organ and system functioning and, in certain cases, mental development. Enzyme replacement therapies are currently in use or are being tested for at least three different subtypes (I, II and VI). The aim of the present study was to evaluate the effectiveness and safety of laronidase for treating mucopolysaccharidosis type I. A systematic review of the literature was conducted. A computerized electronic search was then conducted using the CENTRAL, Pubmed, EMBASE, and LILACS databases, to identify any randomized controlled trials. The last date of the search was June 2006. There was no possibility of combining the results, because only one study was included. In the pivotal placebo-controlled trial conducted over a 26-week period, there was a reduction in the urinary excretion of GAGs among treated patients. Regarding adverse events, there were no laronidase-related serious adverse events or deaths. Laronidase seems to be a promising agent for treating mucopolysaccharidosis type I, as shown by the reduction in the urinary excretion of GAGs and the associated improvements in vital capacity and in the performance of defined physical tasks.

ABSTRACT. The Kayabi Indians who inhabit the Xingu Indigenous Park, located in West Central Brazil, have grown and managed peanuts for a long time. A great number of landraces are being maintained by these tribes and some of this germplasm has morphological traits that exceed the variation described in the taxonomic literature. Here, we analyzed the genetic variability of these landraces using a set of microsatellite markers. The analysis showed that, in general, the indigenous samples grouped according to the villages where they were collected. The microsatellite markers used in the present study detected high levels of genetic variation. Similarity groups, genetically distant from each other, were formed, allowing a more efficient use of the existing genetic variability. The present study also showed that these materials can extend the genetic variability available for peanut-breeding programs. Additionally, the microsatellite markers revealed a large dissimilarity among germplasm accessions representing Arachis hypogaea varieties so far included in the same subspecies fastigiata (aequatoriana + peruviana vs fastigiata + vulgaris), a subject that deserves further investigation. Finally, the Xingu Indigenous Park proved to be an important center of diversity for peanut.

ABSTRACT. We describe a simple method to compute the numerator relationship between any or all pairs of animals in the numerator relationship matrix. The method depends on output of the MTDFNRM program from the MTDFREML set of programs. An option of the MTDFNRM program creates a file that includes the inbreeding coefficient for each animal. The method also makes use of how the inbreeding coefficient is traditionally calculated: one-half of the relationship between the animal’s parents. To obtain the numerator relationship between any pair of animals, the original pedigree file is augmented with a dummy animal with an identification number (ID) greater than for any animal in the original pedigree file. The ID of the pair of animals for which the relationship is wanted is included as parents. MTDFNRM is then run with the option to create a file of ordered and original IDs for animals and their parents along with the inbreeding coefficients. We then multiply the inbreeding coefficient for a dummy animal by two to obtain the numerator relationship between the two animals designated as parents.

ABSTRACT. The present study describes a new set of 61 polymorphic microsatellite markers for beans and the construction of a genetic map using the BAT93 x Jalo EEP558 (BJ) population for the purpose of developing a reference linkage map for common bean (Phaseolus vulgaris). The main objectives were to integrate new microsatellites on the existing framework map of the BJ population, and to develop the first linkage map for the BJ population based exclusively on microsatellites. Of the total of 264 microsatellites evaluated for polymorphism, 42.8% showed polymorphism between the genitors. An integrated map was created totaling 199 mapped markers in 13 linkage groups, with an observed length of 1358 cM and a mean distance between markers of 7.23 cM. For the map constructed exclusively with microsatellites, 106 markers were placed in 12 groups with a total length of 606.8 cM and average distance of 6.8 cM. Linkage group designation and marker order for BM microsatellites generally agreed with previous mapping, while the new microsatellites were well distributed across the genome, corroborating the utility of the BJ population for a reference map. The extensive use of the microsatellites and the availability of a reference map can help in the development of other genetic maps for common bean through the transfer of information of marker order and linkage, which will allow comparative analysis and map integration, especially for future quantitative trait loci and association mapping studies.

ABSTRACT. Cratylia argentea and C. mollis (Fabaceae-Papilionoideae) are legume shrubs native to the Cerrado and Caatinga, respectively. Both species show great resistance to drought and high nutritive value, which makes them a valuable forage resource in tropical regions. Cytogenetic studies were carried out on accessions of C. argentea and C. mollis from Germplasm Banks of Embrapa Gado de Leite (Juiz de Fora, MG) and Embrapa Semi-Árido (Petrolina, PE), respectively. Root tips were treated with 3 mM 8-hydroxyquinoline and slides were made using the air-dry technique. Karyotype description for each accession took into account the following features: chromosome number; total length, relative length and arm ratio of each chromosome; haploid set length, and degree of asymmetry. Mitotic metaphases in both species showed 2n = 22 chromosomes, where this is the first report of diploid number for C. mollis. Chromosome length was also quite similar for the two species, ranging from 5.08 to 2.50 µm in C. argentea and 5.12 to 2.51 µm in C. mollis, with haploid sets of equal size, measuring 38.10 and 37.85 µm, respectively. However, they did not show the same karyotypic formula, which was 5 m + 4 sm + 2 st for C. argentea and 7 m + 2 sm + 2 st for C. mollis. This indicates the occurrence of rearrangements within chromosomes I and VI. Both karyotypes showed a tendency for asymmetry.

ABSTRACT. A comparative study of holocentric chromosomes in the triatomine species Panstrongylus megistus, Rhodnius pallescens and Triatoma infestans was carried out in order to characterize heterochromatin, rDNA active sites and nucleolar proteins. Cytological preparations of seminiferous tubules were stained by silver impregnation, C banding, fluorochromes cma₃/da and dapi/da, and fluorescent in situ hybridization (FISH) with Drosophila melanogaster 28S rDNA probe. Our results showed interesting aspects of the organization of chromatin and chromosomes in the meiotic cells of these insects. In R. pallescens, sex chromosomes (X, Y) were distinct from autosomes, when submitted to silver impregnation, C banding, CMA₃ staining, and FISH, confirming that these chromosomes bear nucleolar organizer regions (NORs). In P. megistus, two of the three sex chromosomes were CMA₃/DAPI^-; at early meiotic prophase and at diakinesis, silver impregnation corresponded with FISH signals, indicating that in this species, two chromosomes (probably a sex chromosome and an autosome) bear NORs. In T. infestans, silver nitrate and FISH also stained corresponding areas on meiotic chromosomes. Our data suggest that in triatomines, in general, the number and location of NORs are species-specific. These regions may be considered important chromosome markers for comparative studies to improve the understanding of evolutionary mechanisms in these hematophagous insects.

ABSTRACT. The present study was designed to identify nutrient-dependent changes in extracellular pH and acid phosphatase secretion in the biA1 palC4 mutant strain of Aspergillus nidulans. The palC4 mutant was selected as lacking alkaline phosphatase, but having substantially increased acid phosphatase activity when grown on solid minimal medium under phosphate starvation, pH 6.5. Gene palC was identified as a putative member of a conserved signaling cascade involved in ambient alkaline sensing whose sole function is to promote the proteolytic activation of PacC at alkaline pH. We showed that both poor growth and conidiation of the palC4 mutant strain on solid medium, alkaline pH, were relative to its hypersensitivity to Tris (hydroxymethyl) aminomethane buffer. Also, the secretion of acid phosphatase was repressed when both the wild-type and palC4 mutant strains were grown in low-phosphate yeast extract liquid medium, pH 5.0, indicating that the secretion of this enzyme is not necessary to regenerate inorganic phosphate from the organic phosphate pool present in yeast extract.